From 7d6bd448606592655e072afefedde862f9e8eb32 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Thu, 11 Nov 2021 10:21:50 -0500
Subject: [PATCH 01/24] Updated compiler flags to consolidate include and link
 flags into Makefile.Defines, and modified advisor profiling flags

---
 Makefile         | 18 +++++++++---------
 Makefile.Defines | 43 ++++++++++++++++++++++++++++++++++---------
 2 files changed, 43 insertions(+), 18 deletions(-)

diff --git a/Makefile b/Makefile
index d1da4b19f..09fcfcc0b 100644
--- a/Makefile
+++ b/Makefile
@@ -65,8 +65,8 @@ MODULES         = $(SWIFTEST_MODULES) $(USER_MODULES)
 .PHONY : all mod fast strict drivers bin clean force 
 
 % : %.f90 force
-	$(FORTRAN) $(FFLAGS) -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include $(IMKL) $(IADVIXE) $< -o $@ \
-	  -L$(SWIFTEST_HOME)/lib -lswiftest -L$(NETCDF_FORTRAN_HOME)/lib -lnetcdf -lnetcdff $(LMKL) $(LADVIXE)
+	$(FORTRAN) $(FFLAGS) $(INCLUDES) $< -o $@ \
+	  -L$(SWIFTEST_HOME)/lib $(LINKS) 
 	$(INSTALL_PROGRAM) $@ $(SWIFTEST_HOME)/bin
 	rm -f $@
 
@@ -79,7 +79,7 @@ all:
 
 mod:
 	cd $(SWIFTEST_HOME)/src/modules/; \
-	  $(FORTRAN) $(FFLAGS) -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include $(IMKL) $(IADVIXE) -c $(MODULES); \
+	  $(FORTRAN) $(FFLAGS) $(INCLUDES) -c $(MODULES); \
 	  $(AR) rv $(SWIFTEST_HOME)/lib/libswiftest.a *.o; \
 	  $(INSTALL_DATA) *.mod *.smod $(SWIFTEST_HOME)/include; \
 	  rm -f *.o *.mod  *.smod
@@ -188,34 +188,34 @@ strict:
 	  ln -s $(SWIFTEST_HOME)/Makefile .; \
 	  make strictdir
 	cd $(SWIFTEST_HOME)/src/helio; \
-		$(FORTRAN) $(FSTRICTFLAGS) -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include $(IMKL) $(IADVIXE) -c helio_kick.f90; \
+		$(FORTRAN) $(FSTRICTFLAGS) $(INCLUDES) -c helio_kick.f90; \
 		$(AR) rv $(SWIFTEST_HOME)/lib/libswiftest.a *.o *.smod; \
 		$(INSTALL_DATA) *.smod $(SWIFTEST_HOME)/include; \
 		rm -f *.o *.smod	
 	cd $(SWIFTEST_HOME)/src/symba; \
-		$(FORTRAN) $(FSTRICTFLAGS) -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include $(IMKL) $(IADVIXE) -c symba_kick.f90; \
+		$(FORTRAN) $(FSTRICTFLAGS) $(INCLUDES) -c symba_kick.f90; \
 		$(AR) rv $(SWIFTEST_HOME)/lib/libswiftest.a *.o *.smod; \
 		$(INSTALL_DATA) *.smod $(SWIFTEST_HOME)/include; \
 		rm -f *.o *.smod
 	cd $(SWIFTEST_HOME)/src/rmvs; \
-		$(FORTRAN) $(FSTRICTFLAGS) -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include $(IMKL) $(IADVIXE) -c rmvs_kick.f90; \
+		$(FORTRAN) $(FSTRICTFLAGS) $(INCLUDES) -c rmvs_kick.f90; \
 		$(AR) rv $(SWIFTEST_HOME)/lib/libswiftest.a *.o *.smod; \
 		$(INSTALL_DATA) *.smod $(SWIFTEST_HOME)/include; \
 		rm -f *.o *.smod	
 	cd $(SWIFTEST_HOME)/src/whm; \
-		$(FORTRAN) $(FSTRICTFLAGS) -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include $(IMKL) $(IADVIXE) -c whm_kick.f90; \
+		$(FORTRAN) $(FSTRICTFLAGS) $(INCLUDES) -c whm_kick.f90; \
 		$(AR) rv $(SWIFTEST_HOME)/lib/libswiftest.a *.o *.smod; \
 		$(INSTALL_DATA) *.smod $(SWIFTEST_HOME)/include; \
 		rm -f *.o *.smod
 
 fastdir:
-	$(FORTRAN) $(FFLAGS) -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include $(IMKL) $(IADVIXE) -c *.f90; \
+	$(FORTRAN) $(FFLAGS) $(INCLUDES) -c *.f90; \
 	$(AR) rv $(SWIFTEST_HOME)/lib/libswiftest.a *.o *.smod; \
 	$(INSTALL_DATA) *.smod $(SWIFTEST_HOME)/include; \
 	rm -f *.o *.smod
 
 strictdir:
-	$(FORTRAN) $(FSTRICTFLAGS) -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include $(IMKL) $(IADVIXE) -c *.f90; \
+	$(FORTRAN) $(FSTRICTFLAGS) $(INCLUDES) -c *.f90; \
 	$(AR) rv $(SWIFTEST_HOME)/lib/libswiftest.a *.o *.smod; \
 	$(INSTALL_DATA) *.smod $(SWIFTEST_HOME)/include; \
 	rm -f *.o *.smo	
diff --git a/Makefile.Defines b/Makefile.Defines
index 1fdf74d45..7511981dd 100644
--- a/Makefile.Defines
+++ b/Makefile.Defines
@@ -41,28 +41,53 @@ SWIFTEST_HOME    = $(ROOT_DIR)
 USER_MODULES    =
 COLLRESOLVE_HOME = $(ROOT_DIR)/collresolve/
 
+#NETCDF_FORTRAN_HOME = /home/daminton/local
+
+
 # Compiler definitions
 
 # DO NOT include in FFLAGS the "-c" option to compile object only
 # this is done explicitly as needed in the Makefile
-ADVIXE_FLAGS = -g -O2 -qopt-report=5 -vec -shared-intel -ldl -debug inline-debug-info -DTBB_DEBUG -DTBB_USE_THREADING_TOOLS -traceback 
-#Be sure to set the environment variable KMP_FORKJOIN_FRAMES=1 for OpenMP debuging in vtune
 
+IDEBUG = -O0 -init=snan,arrays  -nogen-interfaces -no-pie -no-ftz -fpe-all=0 -g -traceback -mp1 -qopt-matmul -fp-model strict -fpe0 -debug all -align all -pad -ip -prec-div -prec-sqrt -assume protect-parens -CB -no-wrap-margin
 STRICTREAL = -fp-model=precise -prec-div -prec-sqrt -assume protect-parens 
-SIMDVEC = -simd -xhost -align all -assume contiguous_assumed_shape -vecabi=cmdtarget -fp-model no-except -fma
+SIMDVEC = -simd -xhost -align all -pad -assume contiguous_assumed_shape -vecabi=cmdtarget -fp-model no-except -fma
 PAR = -qopenmp -parallel  
+HEAPARR = -heap-arrays 4194304 
+OPTREPORT = -qopt-report=5 
+ADVIXE_FLAGS = -g -O2 -qopt-report=5 -shared-intel -traceback $(SIMDVEC) $(PAR)
+#Be sure to set the environment variable KMP_FORKJOIN_FRAMES=1 for OpenMP debuging in vtune/advisor
+
+IPRODUCTION = -no-wrap-margin -O3 -qopt-prefetch=0 -qopt-matmul -sox $(PAR) $(SIMDVEC) #$(HEAPARR)
+
+#gfortran flags
+GDEBUG = -g -Og -fbacktrace -fbounds-check -ffree-line-length-none
+GPAR = -fopenmp -ftree-parallelize-loops=4
+GMEM =  -fsanitize-address-use-after-scope -fstack-check  -fsanitize=bounds-strict -fsanitize=undefined -fsanitize=signed-integer-overflow -fsanitize=object-size -fstack-protector-all
+GWARNINGS = -Wall -Warray-bounds  -Wimplicit-interface -Wextra -Warray-temporaries
+GPRODUCTION = -O3 -ffree-line-length-none $(GPAR)
 
-MKL_ROOT = /apps/spack/bell/apps/intel-parallel-studio/cluster.2019.5-intel-19.0.5-4brgqlf/mkl/lib
-IMKL = -I$(MKLROOT)/include
-LMKL = -L$(MKLROOT)/lib/intel64 -qopt-matmul 
+INCLUDES = -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include -I$(MKLROOT)/include -I$(ADVISOR_2019_DIR)/include/intel64
+LINKS = -L$(MKLROOT)/lib/intel64 -L$(NETCDF_FORTRAN_HOME)/lib -L$(ADVISOR_2019_DIR)/lib64 -lswiftest -lnetcdf -lnetcdff -ladvisor 
 
-FSTRICTFLAGS = $(ADVIXE_FLAGS) $(STRICTREAL) $(SIMDVEC) $(PAR)
-FFLAGS = $(ADVIXE_FLAGS) -fp-model=fast $(SIMDVEC) $(PAR)
+# FSTRICTFLAGS  = $(IDEBUG) $(SIMDVEC) $(PAR)
+# FFLAGS  = $(IDEBUG) $(SIMDVEC) $(PAR)
+
+FSTRICTFLAGS = $(ADVIXE_FLAGS) $(STRICTREAL) 
+FFLAGS = $(ADVIXE_FLAGS) -fp-model=fast 
 FORTRAN = ifort
 AR     = xiar
 CC    = icc
 
-CC              = icc
+#FORTRAN = gfortran
+#FFLAGS =  $(GDEBUG)  $(GMEM) #$(GPAR)
+#FSTRICTFLAGS =  $(GDEBUG)  $(GMEM) #$(GPAR)
+#AR     = ar 
+#CC     = cc
+
+# DO NOT include in CFLAGS the "-c" option to compile object only
+# this is done explicitly as needed in the Makefile
+
 CFLAGS          = -O3 -w -m64 -std=c99
 
 64_BIT_REALS    = -r8

From b4f397f6cef2c6d9f490a282f2097c48dcd1434c Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Fri, 12 Nov 2021 16:14:45 -0500
Subject: [PATCH 02/24] Updated profiling branch with better flags and tweaks
 to the encounter checking

---
 Makefile.Defines                  |  18 ++-
 src/encounter/encounter_check.f90 | 189 ++++++++++++++----------------
 2 files changed, 103 insertions(+), 104 deletions(-)

diff --git a/Makefile.Defines b/Makefile.Defines
index 760e05e25..9264c39c6 100644
--- a/Makefile.Defines
+++ b/Makefile.Defines
@@ -48,13 +48,15 @@ COLLRESOLVE_HOME = $(ROOT_DIR)/collresolve/
 
 # DO NOT include in FFLAGS the "-c" option to compile object only
 # this is done explicitly as needed in the Makefile
-ADVIXE_FLAGS = -g -O2 -qopt-report=5 -vecabi=cmdtarget -simd -shared-intel -debug inline-debug-info -DTBB_DEBUG -DTBB_USE_THREADING_TOOLS -xhost -traceback -I$(ADVISOR_2019_DIR)/include/intel64 -parallel-source-info=2 
+ADVIXE_INCLUDE = -I$(ADVISOR_2019_DIR)/include/intel64 
+ADVIXE_LINK = -L$(ADVISOR_2019_DIR)/lib64 -ladvisor
+ADVIXE_FLAGS = -g -O2 -qopt-report=5 -vecabi=cmdtarget -simd -shared-intel -debug inline-debug-info -DTBB_DEBUG -DTBB_USE_THREADING_TOOLS -xhost -traceback 
 #Be sure to set the environment variable KMP_FORKJOIN_FRAMES=1 for OpenMP debuging in vtune
 
 IDEBUG = -O0 -init=snan,arrays  -nogen-interfaces -no-pie -no-ftz -fpe-all=0 -g -traceback -mp1 -qopt-matmul -fp-model strict -fpe0 -debug all -align all -pad -ip -prec-div -prec-sqrt -assume protect-parens -CB -no-wrap-margin
 STRICTREAL = -fp-model=precise -prec-div -prec-sqrt -assume protect-parens 
-SIMDVEC = -simd -xhost -align all -assume contiguous_assumed_shape -vecabi=cmdtarget -fp-model no-except -fma
-PAR = -qopenmp -parallel
+SIMDVEC = -simd -xhost -align all -pad -assume contiguous_assumed_shape -vecabi=cmdtarget -fp-model no-except -fma 
+PAR = -qopenmp -parallel -parallel-source-info=2 
 HEAPARR = -heap-arrays 4194304 
 OPTREPORT = -qopt-report=5 
 IPRODUCTION = -no-wrap-margin -O3 -qopt-prefetch=0 -qopt-matmul -sox $(PAR) $(SIMDVEC) #$(HEAPARR)
@@ -67,9 +69,13 @@ GWARNINGS = -Wall -Warray-bounds  -Wimplicit-interface -Wextra -Warray-temporari
 GPRODUCTION = -O3 -ffree-line-length-none $(GPAR)
 
 INCLUDES = -I$(SWIFTEST_HOME)/include -I$(NETCDF_FORTRAN_HOME)/include -I$(MKLROOT)/include 
-LINKS = -L$(MKLROOT)/lib/intel64 -L$(NETCDF_FORTRAN_HOME)/lib -L$(ADVISOR_2019_DIR)/lib64 -lswiftest -lnetcdf -lnetcdff  -qopt-matmul $(PAR)
-FSTRICTFLAGS = $(ADVIXE_FLAGS) $(STRICTREAL) 
-FFLAGS = $(ADVIXE_FLAGS) -fp-model=fast 
+LINKS = -L$(MKLROOT)/lib/intel64 -L$(NETCDF_FORTRAN_HOME)/lib -lswiftest -lnetcdf -lnetcdff -qopt-matmul $(PAR)
+
+#FSTRICTFLAGS  = $(IDEBUG) $(SIMDVEC) $(PAR)
+#FFLAGS  = $(IDEBUG) $(SIMDVEC) $(PAR)
+
+FSTRICTFLAGS = $(ADVIXE_FLAGS) $(PAR) $(SIMDVEC) $(STRICTREAL) 
+FFLAGS = $(ADVIXE_FLAGS) $(PAR) $(SIMDVEC)  -fp-model=fast 
 FORTRAN = ifort
 AR     = xiar
 CC    = icc
diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index b125d0ff9..1f7550125 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -476,8 +476,6 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
          ntot_last = ntot
       end if
     
-      call timer%reset()
-      call timer%start()
       !$omp parallel do default(private) schedule(static) &
       !$omp shared(xplm, xplt, vplm, vplt, rencm, renct, boundingbox) &
       !$omp firstprivate(dt, nplm, nplt, ntot)
@@ -872,7 +870,7 @@ module subroutine encounter_check_collapse_ragged_list(ragged_list, n1, nenc, in
          j0 = j0 + nenci
       end do
 
-      !$omp parallel do default(private) &
+      !$omp parallel do simd default(private) schedule(simd: static)&
       !$omp shared(ragged_list, index1, index2, ibeg, lvdotr) &
       !$omp firstprivate(n1)
       do i = 1,n1
@@ -884,7 +882,7 @@ module subroutine encounter_check_collapse_ragged_list(ragged_list, n1, nenc, in
          index2(j0:j1) = ragged_list(i)%index2(:)
          if (present(lvdotr)) lvdotr(j0:j1) = ragged_list(i)%lvdotr(:)
       end do
-      !$omp end parallel do
+      !$omp end parallel do simd
 
       return
    end subroutine encounter_check_collapse_ragged_list
@@ -954,18 +952,15 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
       integer(I4B) :: i, k, ntot, dim
       type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
-      integer(I4B), dimension(:), allocatable :: ibeg, iend
+      integer(I4B), dimension(SWEEPDIM * (n1 + n2)) :: ibeg, iend
 
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
-      allocate(ibeg(SWEEPDIM * ntot))
-      allocate(iend(SWEEPDIM * ntot))
-      do i = 1, ntot
-         do dim = 1, SWEEPDIM
-            ibeg((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%ibeg(i)
-            iend((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%iend(i)
-         end do
+      do concurrent (dim=1:SWEEPDIM, i = 1:ntot)
+         ibeg((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%ibeg(i)
+         iend((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%iend(i)
       end do
+
       ! Sweep the intervals for each of the massive bodies along one dimension
       ! This will build a ragged pair of index lists inside of the lenc data structure
       call encounter_check_sweep_aabb_all_double_list(n1, n2, self%aabb(1)%ind(:), reshape(ibeg(:), [SWEEPDIM, ntot]), reshape(iend(:), [SWEEPDIM, ntot]), ind_arr(:), lenc(:))
@@ -1000,16 +995,12 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, nenc, index1,
       type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       type(walltimer) :: timer 
-      integer(I4B), dimension(:), allocatable :: ibeg, iend
+      integer(I4B), dimension(SWEEPDIM * n) :: ibeg, iend
 
       call util_index_array(ind_arr, n)
-      allocate(ibeg(SWEEPDIM * n))
-      allocate(iend(SWEEPDIM * n))
-      do i = 1, n
-         do dim = 1, SWEEPDIM
-            ibeg((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%ibeg(i)
-            iend((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%iend(i)
-         end do
+      do concurrent(dim = 1:SWEEPDIM, i = 1:n)
+         ibeg((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%ibeg(i)
+         iend((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%iend(i)
       end do
 
       ! Sweep the intervals for each of the massive bodies along one dimension
@@ -1049,13 +1040,13 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
       !$omp parallel do default(private) schedule(dynamic)&
       !$omp shared(ext_ind, ibeg, iend, ind_arr, lenc) &
       !$omp firstprivate(ntot, n1, n2) 
-      do i = 1, ntot
+      do i = 1,ntot
          ibegi(1) = ibeg(1,i) + 1
          iendi(1) = iend(1,i) - 1
          if (iendi(1) >= ibegi(1)) then
             ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
             iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            call encounter_check_sweep_aabb_one_double_list(i, n1, n2, ntot, ext_ind(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
+            call sweep_dl(i, n1, n2, ntot, ext_ind(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
             call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), lenc(i)%nenc, lenc(i)%index2)
          else
             lenc(i)%nenc = 0
@@ -1064,6 +1055,45 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
       !$omp end parallel do
 
       return
+
+      contains
+         pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
+            !! author: David A. Minton
+            !!
+            !! Performs a sweep operation on a single body. Encounters from the same lists not allowed (e.g. pl-tp encounters only)
+            implicit none
+            ! Arguments
+            integer(I4B),                 intent(in)  :: i            !! The current index of the ith body
+            integer(I4B),                 intent(in)  :: n1           !! Number of bodies 1
+            integer(I4B),                 intent(in)  :: n2           !! Number of bodies 2
+            integer(I4B),                 intent(in)  :: ntot         !! n1 + n2
+            integer(I4B), dimension(:),   intent(in)  :: ext_ind      !! Sorted index array of extents
+            integer(I4B), dimension(:),   intent(in)  :: ibegi, iendi !! The beginning and ending indices of the ith bounding box in the n-dimensions
+            integer(I4B), dimension(:,:), intent(in)  :: ibeg, iend   !! Beginning and ending index lists in the n-dimensions
+            logical, dimension(:),        intent(out) :: lencounteri    !! Encounter list for the ith body
+            ! Internals
+            integer(I4B) :: j, jbox, dim, jlo, jhi
+            integer(I4B), dimension(ibegi(1):iendi(1)) :: box
+
+            lencounteri(:) = .false.
+            jlo = ibegi(1)
+            jhi = iendi(1)
+            box(:) = ext_ind(jlo:jhi)
+            where(box(:) > ntot)
+               box(:) = box(:) - ntot
+            endwhere
+            
+            do concurrent (jbox = jlo:jhi)
+               j = box(jbox)
+               if (((i <= n1) .and. (j <= n1)) .or. ((i > n1) .and. (j > n1))) cycle  ! only pairs from the two different lists allowed
+               ! Check the other dimensions
+               !lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
+               if ((iend(2,j) < ibegi(2)) .or. ibeg(2,j) > iendi(2)) cycle
+               lencounteri(j) = (iend(SWEEPDIM,j) > ibegi(SWEEPDIM)) .and. (ibeg(SWEEPDIM,j) < iendi(SWEEPDIM))
+            end do
+
+            return
+         end subroutine sweep_dl
    end subroutine encounter_check_sweep_aabb_all_double_list
 
 
@@ -1093,7 +1123,7 @@ subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, in
          if (iendi(1) >= ibegi(1)) then
             ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
             iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            call encounter_check_sweep_aabb_one_single_list(n, ext_ind(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
+            call sweep_sl(n, ext_ind(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
             call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), lenc(i)%nenc, lenc(i)%index2)
          else
             lenc(i)%nenc = 0
@@ -1102,81 +1132,44 @@ subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, in
       !$omp end parallel do
 
       return
-   end subroutine encounter_check_sweep_aabb_all_single_list
-
-
-   pure subroutine encounter_check_sweep_aabb_one_double_list(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
-      !! author: David A. Minton
-      !!
-      !! Performs a sweep operation on a single body. Encounters from the same lists not allowed (e.g. pl-tp encounters only)
-      implicit none
-      ! Arguments
-      integer(I4B),                 intent(in)  :: i            !! The current index of the ith body
-      integer(I4B),                 intent(in)  :: n1           !! Number of bodies 1
-      integer(I4B),                 intent(in)  :: n2           !! Number of bodies 2
-      integer(I4B),                 intent(in)  :: ntot         !! n1 + n2
-      integer(I4B), dimension(:),   intent(in)  :: ext_ind      !! Sorted index array of extents
-      integer(I4B), dimension(:),   intent(in)  :: ibegi, iendi !! The beginning and ending indices of the ith bounding box in the n-dimensions
-      integer(I4B), dimension(:,:), intent(in)  :: ibeg, iend   !! Beginning and ending index lists in the n-dimensions
-      logical, dimension(:),        intent(out) :: lencounteri    !! Encounter list for the ith body
-      ! Internals
-      integer(I4B) :: j, jbox, dim, jlo, jhi
-      integer(I4B), dimension(:), allocatable :: box
-
-      lencounteri(:) = .false.
-      jlo = ibegi(1)
-      jhi = iendi(1)
-      allocate(box(jlo:jhi))
-      box(:) = ext_ind(jlo:jhi)
-      where(box(:) > ntot)
-         box(:) = box(:) - ntot
-      endwhere
       
-      do concurrent (jbox = jlo:jhi)
-         j = box(jbox)
-         if (((i <= n1) .and. (j <= n1)) .or. ((i > n1) .and. (j > n1))) cycle  ! only pairs from the two different lists allowed
-         ! Check the other dimensions
-         lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
-      end do
-
-      return
-   end subroutine encounter_check_sweep_aabb_one_double_list
- 
-
-   pure subroutine encounter_check_sweep_aabb_one_single_list(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
-      !! author: David A. Minton
-      !!
-      !! Performs a sweep operation on a single body. Mutual encounters allowed (e.g. pl-pl)
-      implicit none
-      ! Arguments
-      integer(I4B),                 intent(in)  :: n            !! Number of bodies
-      integer(I4B), dimension(:),   intent(in)  :: ext_ind      !! Sorted index array of extents
-      integer(I4B), dimension(:),   intent(in)  :: ibegi, iendi !! The beginning and ending indices of the ith bounding box in the n-dimensions
-      integer(I4B), dimension(:,:), intent(in)  :: ibeg, iend   !! Beginning and ending index lists in the x-dimension
-      logical, dimension(:),        intent(out) :: lencounteri  !! Encounter list for the ith body
-      ! Internals
-      integer(I4B) :: j, jbox, dim, jlo, jhi
-      integer(I4B), dimension(:), allocatable :: box
-
-      lencounteri(:) = .false.
-
-      jlo = ibegi(1)
-      jhi = iendi(1)
-
-      allocate(box(jlo:jhi))
-      box(:) = ext_ind(jlo:jhi)
-
-      where(box(:) > n)
-         box(:) = box(:) - n
-      endwhere
-
-      do concurrent(jbox = jlo:jhi) ! Sweep forward until the end of the interval
-         j = box(jbox)
-         ! Check the other dimensions
-         lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
-      end do
-
-      return
-   end subroutine encounter_check_sweep_aabb_one_single_list
+      contains
+         pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
+            !! author: David A. Minton
+            !!
+            !! Performs a sweep operation on a single body. Mutual encounters allowed (e.g. pl-pl)
+            implicit none
+            ! Arguments
+            integer(I4B),                 intent(in)  :: n            !! Number of bodies
+            integer(I4B), dimension(:),   intent(in)  :: ext_ind      !! Sorted index array of extents
+            integer(I4B), dimension(:),   intent(in)  :: ibegi, iendi !! The beginning and ending indices of the ith bounding box in the n-dimensions
+            integer(I4B), dimension(:,:), intent(in)  :: ibeg, iend   !! Beginning and ending index lists in the x-dimension
+            logical, dimension(:),        intent(out) :: lencounteri  !! Encounter list for the ith body
+            ! Internals
+            integer(I4B) :: j, jbox, dim, jlo, jhi
+            integer(I4B), dimension(ibegi(1):iendi(1)) :: box
+
+            lencounteri(:) = .false.
+
+            jlo = ibegi(1)
+            jhi = iendi(1)
+
+            box(:) = ext_ind(jlo:jhi)
+
+            where(box(:) > n)
+               box(:) = box(:) - n
+            endwhere
+
+            do concurrent(jbox = jlo:jhi) ! Sweep forward until the end of the interval
+               j = box(jbox)
+               ! Check the other dimensions
+               !lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
+               if ((iend(2,j) < ibegi(2)) .or. ibeg(2,j) > iendi(2)) cycle
+               lencounteri(j) = (iend(SWEEPDIM,j) > ibegi(SWEEPDIM)) .and. (ibeg(SWEEPDIM,j) < iendi(SWEEPDIM))
+            end do
+
+            return
+         end subroutine sweep_sl
+   end subroutine encounter_check_sweep_aabb_all_single_list
 
 end submodule s_encounter_check

From 2e13e188b2bf4358a60e79fd4aba56fe88dd17e6 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Tue, 16 Nov 2021 14:53:07 -0500
Subject: [PATCH 03/24] Updated OpenMP directrives and restructured some loops

---
 src/encounter/encounter_check.f90     | 75 ++++++++++++++++++---------
 src/symba/symba_util.f90              | 18 ++-----
 src/util/util_get_energy_momentum.f90 | 20 +++++--
 3 files changed, 69 insertions(+), 44 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 1f7550125..a29aab6eb 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -1074,23 +1074,43 @@ pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, len
             ! Internals
             integer(I4B) :: j, jbox, dim, jlo, jhi
             integer(I4B), dimension(ibegi(1):iendi(1)) :: box
+            logical, dimension(ibegi(1):iendi(1)) :: lencounterj
 
-            lencounteri(:) = .false.
             jlo = ibegi(1)
             jhi = iendi(1)
-            box(:) = ext_ind(jlo:jhi)
-            where(box(:) > ntot)
-               box(:) = box(:) - ntot
+
+            lencounteri(:) = .false.
+            lencounterj(jlo:jhi) = .false.
+            box(jlo:jhi) = ext_ind(jlo:jhi)
+
+            where(box(jlo:jhi) > ntot)
+               box(jlo:jhi) = box(jlo:jhi) - ntot
             endwhere
+
+            ! only pairs from the two different lists allowed
+            where (box(jlo:jhi) > n1)
+               lencounterj(jlo:jhi) = (i <= n1)
+            elsewhere
+               lencounterj(jlo:jhi) = (i > n1)
+            end where
+
+            where (lencounterj(jlo:jhi) .and. (iend(2,box(jlo:jhi)) > ibegi(2)) .and. (ibeg(2,box(jlo:jhi)) < iendi(2)) )
+               lencounterj(jlo:jhi) = (iend(3,box(jlo:jhi)) > ibegi(3)) .and. (ibeg(3,box(jlo:jhi)) < iendi(3))
+            end where
+            
+            do concurrent(jbox = jlo:jhi)
+               lencounteri(box(jbox)) = lencounterj(jbox)
+            end do
             
-            do concurrent (jbox = jlo:jhi)
-               j = box(jbox)
-               if (((i <= n1) .and. (j <= n1)) .or. ((i > n1) .and. (j > n1))) cycle  ! only pairs from the two different lists allowed
+            !do concurrent (jbox = jlo:jhi, ( ( (i <= n1).and.(box(jbox) > n1) ) .or. ( (i > n1).and.(box(jbox) <= n1) ) ) .and. & 
+               !                              ( ( iend(2,box(j)) >= ibegi(2) )    .and. ( ibeg(2,box(j)) <= iendi(2)   ) ) )
+               !j = box(jbox)
+               !if (((i <= n1) .and. (j <= n1)) .or. ((i > n1) .and. (j > n1))) cycle  ! only pairs from the two different lists allowed
                ! Check the other dimensions
                !lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
-               if ((iend(2,j) < ibegi(2)) .or. ibeg(2,j) > iendi(2)) cycle
-               lencounteri(j) = (iend(SWEEPDIM,j) > ibegi(SWEEPDIM)) .and. (ibeg(SWEEPDIM,j) < iendi(SWEEPDIM))
-            end do
+               !if ((iend(2,j) < ibegi(2)) .or. ibeg(2,j) > iendi(2)) cycle
+            !   lencounteri(box(jbox)) = (iend(SWEEPDIM,box(jbox)) > ibegi(SWEEPDIM)) .and. (ibeg(SWEEPDIM,box(jbox)) < iendi(SWEEPDIM))
+            !end do
 
             return
          end subroutine sweep_dl
@@ -1115,8 +1135,7 @@ subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, in
 
       !$omp parallel do default(private) schedule(dynamic)&
       !$omp shared(ext_ind, ibeg, iend, ind_arr, lenc) &
-      !$omp firstprivate(n) &
-      !$omp lastprivate(ibegi, iendi, lencounteri) 
+      !$omp firstprivate(n) 
       do i = 1, n
          ibegi(1) = ibeg(1,i) + 1
          iendi(1) = iend(1,i) - 1
@@ -1148,26 +1167,34 @@ pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             ! Internals
             integer(I4B) :: j, jbox, dim, jlo, jhi
             integer(I4B), dimension(ibegi(1):iendi(1)) :: box
-
-            lencounteri(:) = .false.
+            logical, dimension(ibegi(1):iendi(1)) :: lencounterj
 
             jlo = ibegi(1)
             jhi = iendi(1)
+            lencounteri(:) = .false.
+            lencounterj(jlo:jhi) = .false.
+            box(jlo:jhi) = ext_ind(jlo:jhi)
 
-            box(:) = ext_ind(jlo:jhi)
-
-            where(box(:) > n)
-               box(:) = box(:) - n
+            where(box(jlo:jhi) > n)
+               box(jlo:jhi) = box(jlo:jhi) - n
             endwhere
 
-            do concurrent(jbox = jlo:jhi) ! Sweep forward until the end of the interval
-               j = box(jbox)
-               ! Check the other dimensions
-               !lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
-               if ((iend(2,j) < ibegi(2)) .or. ibeg(2,j) > iendi(2)) cycle
-               lencounteri(j) = (iend(SWEEPDIM,j) > ibegi(SWEEPDIM)) .and. (ibeg(SWEEPDIM,j) < iendi(SWEEPDIM))
+            where ((iend(2,box(jlo:jhi)) > ibegi(2) ) .and. (ibeg(2,box(jlo:jhi)) < iendi(2)) )
+               lencounterj(jlo:jhi) = (iend(3,box(jlo:jhi)) > ibegi(3)) .and. (ibeg(3,box(jlo:jhi)) < iendi(3))
+            end where
+
+            do concurrent(jbox = jlo:jhi)
+               lencounteri(box(jbox)) = lencounterj(jbox)
             end do
 
+            ! do concurrent(jbox = jlo:jhi) ! Sweep forward until the end of the interval
+            !    j = box(jbox)
+            !    ! Check the other dimensions
+            !    !lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
+            !    if ((iend(2,j) < ibegi(2)) .or. ibeg(2,j) > iendi(2)) cycle
+            !    lencounteri(j) = (iend(SWEEPDIM,j) > ibegi(SWEEPDIM)) .and. (ibeg(SWEEPDIM,j) < iendi(SWEEPDIM))
+            ! end do
+
             return
          end subroutine sweep_sl
    end subroutine encounter_check_sweep_aabb_all_single_list
diff --git a/src/symba/symba_util.f90 b/src/symba/symba_util.f90
index 5a985faea..fcb576d0f 100644
--- a/src/symba/symba_util.f90
+++ b/src/symba/symba_util.f90
@@ -403,7 +403,7 @@ module subroutine symba_util_flatten_eucl_plpl(self, param)
       integer(I8B) :: k, npl, nplm
       integer(I4B) :: i, j, err
 
-      associate(pl => self, nplpl => self%nplpl, nplplm => self%nplplm)
+      associate(pl => self, nplplm => self%nplplm)
          npl = int(self%nbody, kind=I8B)
          select type(param)
          class is (symba_parameters)
@@ -411,21 +411,9 @@ module subroutine symba_util_flatten_eucl_plpl(self, param)
          end select
          nplm = count(.not. pl%lmtiny(1:npl))
          pl%nplm = int(nplm, kind=I4B)
-         nplpl = (npl * (npl - 1_I8B)) / 2_I8B ! number of entries in a strict lower triangle, npl x npl, minus first column
          nplplm = nplm * npl - nplm * (nplm + 1_I8B) / 2_I8B ! number of entries in a strict lower triangle, npl x npl, minus first column including only mutually interacting bodies
-         if (param%lflatten_interactions) then
-            if (allocated(self%k_plpl)) deallocate(self%k_plpl) ! Reset the index array if it's been set previously
-            allocate(self%k_plpl(2, nplpl), stat=err)
-            if (err /= 0) then ! An error occurred trying to allocate this big array. This probably means it's too big to fit in memory, and so we will force the run back into triangular mode
-               param%lflatten_interactions = .false.
-            else
-               do concurrent (i=1:npl, j=1:npl, j>i)
-                  call util_flatten_eucl_ij_to_k(self%nbody, i, j, k)
-                  self%k_plpl(1, k) = i
-                  self%k_plpl(2, k) = j
-               end do
-            end if
-         end if
+
+         call util_flatten_eucl_plpl(pl, param)
       end associate
 
       return
diff --git a/src/util/util_get_energy_momentum.f90 b/src/util/util_get_energy_momentum.f90
index 3474e2921..b935a680c 100644
--- a/src/util/util_get_energy_momentum.f90
+++ b/src/util/util_get_energy_momentum.f90
@@ -144,7 +144,8 @@ subroutine util_get_energy_potential_flat(npl, nplpl, k_plpl, lmask, GMcb, Gmass
       end do
 
       !$omp parallel do default(private) schedule(static)&
-      !$omp shared(nplpl, k_plpl, xb, mass, Gmass, pepl, lstatpl, lmask)
+      !$omp shared(k_plpl, xb, mass, Gmass, pepl, lstatpl, lmask) &
+      !$omp firstprivate(nplpl)
       do k = 1, nplpl
          i = k_plpl(1,k)
          j = k_plpl(2,k)
@@ -178,7 +179,7 @@ subroutine util_get_energy_potential_triangular(npl, lmask, GMcb, Gmass, mass, x
       real(DP),                     intent(out) :: pe
       ! Internals
       integer(I4B) :: i, j
-      real(DP), dimension(npl) :: pecb
+      real(DP), dimension(npl) :: pecb, pepl
 
       ! Do the central body potential energy component first
       where(.not. lmask(1:npl))
@@ -189,10 +190,19 @@ subroutine util_get_energy_potential_triangular(npl, lmask, GMcb, Gmass, mass, x
          pecb(i) = -GMcb * mass(i) / norm2(xb(:,i)) 
       end do
 
-      pe = sum(pecb(1:npl), lmask(1:npl))
-      do concurrent(i = 1:npl, j = 1:npl, (j > i) .and. lmask(i) .and. lmask(j))
-         pe = pe - (Gmass(i) * mass(j)) / norm2(xb(:, i) - xb(:, j))
+      pe = 0.0_DP
+      !$omp parallel do default(private) schedule(static)&
+      !$omp shared(lmask, Gmass, mass, xb) &
+      !$omp firstprivate(npl) &
+      !$omp reduction(+:pe) 
+      do i = 1, npl
+         do concurrent(j = i+1:npl, lmask(i) .and. lmask(j))
+            pepl(j) = - (Gmass(i) * mass(j)) / norm2(xb(:, i) - xb(:, j))
+         end do
+         pe = pe + sum(pepl(i+1:npl), lmask(i) .and. lmask(j))
       end do
+      !$omp end parallel do
+      pe = pe + sum(pecb(1:npl), lmask(1:npl))
 
       return
    end subroutine util_get_energy_potential_triangular

From 8328c7ae11e1560d3499fcd75e7b67a9abb91f18 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Wed, 17 Nov 2021 00:41:59 -0500
Subject: [PATCH 04/24] Rearranged sweep step to be much more efficient

---
 src/encounter/encounter_check.f90 | 59 +++++++++++++++++--------------
 1 file changed, 32 insertions(+), 27 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index a29aab6eb..fe1cfae2e 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -1057,6 +1057,7 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
       return
 
       contains
+
          pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             !! author: David A. Minton
             !!
@@ -1075,13 +1076,14 @@ pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, len
             integer(I4B) :: j, jbox, dim, jlo, jhi
             integer(I4B), dimension(ibegi(1):iendi(1)) :: box
             logical, dimension(ibegi(1):iendi(1)) :: lencounterj
+            integer(I4B), dimension(NDIM, ibegi(1):iendi(1)) :: iend_box, ibeg_box
 
             jlo = ibegi(1)
             jhi = iendi(1)
 
             lencounteri(:) = .false.
             lencounterj(jlo:jhi) = .false.
-            box(jlo:jhi) = ext_ind(jlo:jhi)
+            box(:) = ext_ind(jlo:jhi)
 
             where(box(jlo:jhi) > ntot)
                box(jlo:jhi) = box(jlo:jhi) - ntot
@@ -1094,24 +1096,23 @@ pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, len
                lencounterj(jlo:jhi) = (i > n1)
             end where
 
-            where (lencounterj(jlo:jhi) .and. (iend(2,box(jlo:jhi)) > ibegi(2)) .and. (ibeg(2,box(jlo:jhi)) < iendi(2)) )
-               lencounterj(jlo:jhi) = (iend(3,box(jlo:jhi)) > ibegi(3)) .and. (ibeg(3,box(jlo:jhi)) < iendi(3))
+            ibeg_box(1:NDIM,jlo:jhi) = ibeg(1:NDIM,box(jlo:jhi))
+            iend_box(1:NDIM,jlo:jhi) = iend(1:NDIM,box(jlo:jhi))
+
+            where (lencounterj(jlo:jhi))
+               where (iend_box(2,jlo:jhi) > ibegi(2))
+                  where (ibeg_box(2,jlo:jhi) < iendi(2))
+                     where (iend_box(3,jlo:jhi) > ibegi(3))
+                        lencounterj(jlo:jhi) = (ibeg_box(3,jlo:jhi) < iendi(3))
+                     end where
+                  end where
+               end where
             end where
             
             do concurrent(jbox = jlo:jhi)
                lencounteri(box(jbox)) = lencounterj(jbox)
             end do
             
-            !do concurrent (jbox = jlo:jhi, ( ( (i <= n1).and.(box(jbox) > n1) ) .or. ( (i > n1).and.(box(jbox) <= n1) ) ) .and. & 
-               !                              ( ( iend(2,box(j)) >= ibegi(2) )    .and. ( ibeg(2,box(j)) <= iendi(2)   ) ) )
-               !j = box(jbox)
-               !if (((i <= n1) .and. (j <= n1)) .or. ((i > n1) .and. (j > n1))) cycle  ! only pairs from the two different lists allowed
-               ! Check the other dimensions
-               !lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
-               !if ((iend(2,j) < ibegi(2)) .or. ibeg(2,j) > iendi(2)) cycle
-            !   lencounteri(box(jbox)) = (iend(SWEEPDIM,box(jbox)) > ibegi(SWEEPDIM)) .and. (ibeg(SWEEPDIM,box(jbox)) < iendi(SWEEPDIM))
-            !end do
-
             return
          end subroutine sweep_dl
    end subroutine encounter_check_sweep_aabb_all_double_list
@@ -1135,7 +1136,8 @@ subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, in
 
       !$omp parallel do default(private) schedule(dynamic)&
       !$omp shared(ext_ind, ibeg, iend, ind_arr, lenc) &
-      !$omp firstprivate(n) 
+      !$omp firstprivate(n) &
+      !$omp lastprivate(ibegi, iendi, lencounteri) 
       do i = 1, n
          ibegi(1) = ibeg(1,i) + 1
          iendi(1) = iend(1,i) - 1
@@ -1153,6 +1155,7 @@ subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, in
       return
       
       contains
+
          pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             !! author: David A. Minton
             !!
@@ -1168,35 +1171,37 @@ pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             integer(I4B) :: j, jbox, dim, jlo, jhi
             integer(I4B), dimension(ibegi(1):iendi(1)) :: box
             logical, dimension(ibegi(1):iendi(1)) :: lencounterj
+            integer(I4B), dimension(NDIM, ibegi(1):iendi(1)) :: iend_box, ibeg_box
 
             jlo = ibegi(1)
             jhi = iendi(1)
+
             lencounteri(:) = .false.
             lencounterj(jlo:jhi) = .false.
-            box(jlo:jhi) = ext_ind(jlo:jhi)
+            box(:) = ext_ind(jlo:jhi)
 
-            where(box(jlo:jhi) > n)
-               box(jlo:jhi) = box(jlo:jhi) - n
+            where(box(:) > n)
+               box(:) = box(:) - n
             endwhere
 
-            where ((iend(2,box(jlo:jhi)) > ibegi(2) ) .and. (ibeg(2,box(jlo:jhi)) < iendi(2)) )
-               lencounterj(jlo:jhi) = (iend(3,box(jlo:jhi)) > ibegi(3)) .and. (ibeg(3,box(jlo:jhi)) < iendi(3))
+            ibeg_box(:,jlo:jhi) = ibeg(:,box(jlo:jhi))
+            iend_box(:,jlo:jhi) = iend(:,box(jlo:jhi))
+
+            where (iend_box(2,jlo:jhi) > ibegi(2))
+               where (ibeg_box(2,jlo:jhi) < iendi(2))
+                  where (iend_box(3,jlo:jhi) > ibegi(3))
+                     lencounterj(jlo:jhi) = (ibeg_box(3,jlo:jhi) < iendi(3))
+                  end where
+               end where
             end where
 
             do concurrent(jbox = jlo:jhi)
                lencounteri(box(jbox)) = lencounterj(jbox)
             end do
 
-            ! do concurrent(jbox = jlo:jhi) ! Sweep forward until the end of the interval
-            !    j = box(jbox)
-            !    ! Check the other dimensions
-            !    !lencounteri(j) = all((iend(2:SWEEPDIM,j) > ibegi(2:SWEEPDIM)) .and. (ibeg(2:SWEEPDIM,j) < iendi(2:SWEEPDIM)))
-            !    if ((iend(2,j) < ibegi(2)) .or. ibeg(2,j) > iendi(2)) cycle
-            !    lencounteri(j) = (iend(SWEEPDIM,j) > ibegi(SWEEPDIM)) .and. (ibeg(SWEEPDIM,j) < iendi(SWEEPDIM))
-            ! end do
-
             return
          end subroutine sweep_sl
+
    end subroutine encounter_check_sweep_aabb_all_single_list
 
 end submodule s_encounter_check

From c6ece4e61f2f366bc3c910134358bc4ab28bc1fa Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Wed, 17 Nov 2021 12:42:26 -0500
Subject: [PATCH 05/24] More streamlining of the sweep step.

---
 src/encounter/encounter_check.f90 | 102 ++++++++++++++++++++----------
 1 file changed, 69 insertions(+), 33 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index fe1cfae2e..14e666855 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -464,7 +464,7 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
       logical, dimension(:), allocatable :: lencounter
       integer(I2B), dimension(nplm) :: vplmshift_min, vplmshift_max
       integer(I2B), dimension(nplt) :: vpltshift_min, vpltshift_max
-      type(walltimer) :: timer 
+      logical, save :: lfirst=.true.
 
       ! If this is the first time through, build the index lists
       if ((nplm == 0) .or. (nplt == 0)) return
@@ -475,7 +475,7 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
          call boundingbox%setup(ntot, ntot_last)
          ntot_last = ntot
       end if
-    
+
       !$omp parallel do default(private) schedule(static) &
       !$omp shared(xplm, xplt, vplm, vplt, rencm, renct, boundingbox) &
       !$omp firstprivate(dt, nplm, nplt, ntot)
@@ -502,7 +502,7 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
                                                 xplt(dim,1:nplt) + renct(1:nplt) + vpltshift_max(1:nplt) * vplt(dim,1:nplt) * dt])
       end do
       !$omp end parallel do
-      
+
       call boundingbox%sweep(nplm, nplt, nenc, index1, index2)
 
       if (nenc > 0) then
@@ -953,6 +953,13 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
       type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I4B), dimension(SWEEPDIM * (n1 + n2)) :: ibeg, iend
+      type(walltimer), save :: sweep_timer
+      logical, save :: lfirst=.true.
+
+      if (lfirst) then
+         call sweep_timer%reset()
+         lfirst = .false.
+      end if
 
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
@@ -961,9 +968,12 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
          iend((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%iend(i)
       end do
 
+      call sweep_timer%start()
       ! Sweep the intervals for each of the massive bodies along one dimension
       ! This will build a ragged pair of index lists inside of the lenc data structure
       call encounter_check_sweep_aabb_all_double_list(n1, n2, self%aabb(1)%ind(:), reshape(ibeg(:), [SWEEPDIM, ntot]), reshape(iend(:), [SWEEPDIM, ntot]), ind_arr(:), lenc(:))
+      call sweep_timer%stop()
+      call sweep_timer%report(nsubsteps=1, message="double sweep    (total / total per thread):")
       
       call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2)
 
@@ -1035,11 +1045,22 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
       integer(I4B) :: i, ntot
       logical, dimension(n1+n2) :: lencounteri
       integer(I4B), dimension(SWEEPDIM) :: ibegi, iendi
-
+      type(walltimer), save :: timer1, timer2, timer3, timer4, timer5
+      logical, save :: lfirst=.true.
+
+      if (lfirst) then
+         call timer1%reset()
+         call timer2%reset()
+         call timer3%reset()
+         call timer4%reset()
+         call timer5%reset()
+         lfirst = .false.
+      end if     
+      
       ntot = n1 + n2
-      !$omp parallel do default(private) schedule(dynamic)&
-      !$omp shared(ext_ind, ibeg, iend, ind_arr, lenc) &
-      !$omp firstprivate(ntot, n1, n2) 
+      !!$omp parallel do default(private) schedule(dynamic)&
+      !!$omp shared(ext_ind, ibeg, iend, ind_arr, lenc) &
+      !!$omp firstprivate(ntot, n1, n2) 
       do i = 1,ntot
          ibegi(1) = ibeg(1,i) + 1
          iendi(1) = iend(1,i) - 1
@@ -1052,13 +1073,19 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
             lenc(i)%nenc = 0
          end if
       end do
-      !$omp end parallel do
+      !!$omp end parallel do
+
+      call timer1%report(nsubsteps=1, message="timer1          (total / total per thread):")
+      call timer2%report(nsubsteps=1, message="timer2          (total / total per thread):")
+      call timer3%report(nsubsteps=1, message="timer3          (total / total per thread):")
+      call timer4%report(nsubsteps=1, message="timer4          (total / total per thread):")
+      call timer5%report(nsubsteps=1, message="timer5          (total / total per thread):")
 
       return
 
       contains
 
-         pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
+         subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             !! author: David A. Minton
             !!
             !! Performs a sweep operation on a single body. Encounters from the same lists not allowed (e.g. pl-tp encounters only)
@@ -1076,8 +1103,10 @@ pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, len
             integer(I4B) :: j, jbox, dim, jlo, jhi
             integer(I4B), dimension(ibegi(1):iendi(1)) :: box
             logical, dimension(ibegi(1):iendi(1)) :: lencounterj
-            integer(I4B), dimension(NDIM, ibegi(1):iendi(1)) :: iend_box, ibeg_box
+            integer(I4B), dimension(ibegi(1):iendi(1)) :: iendy, ibegy
+            integer(I4B), dimension(ibegi(1):iendi(1)) :: iendz, ibegz
 
+            call timer1%start()
             jlo = ibegi(1)
             jhi = iendi(1)
 
@@ -1089,29 +1118,36 @@ pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, len
                box(jlo:jhi) = box(jlo:jhi) - ntot
             endwhere
 
+            call timer1%stop()
+
+            call timer2%start()
             ! only pairs from the two different lists allowed
             where (box(jlo:jhi) > n1)
                lencounterj(jlo:jhi) = (i <= n1)
             elsewhere
                lencounterj(jlo:jhi) = (i > n1)
             end where
-
-            ibeg_box(1:NDIM,jlo:jhi) = ibeg(1:NDIM,box(jlo:jhi))
-            iend_box(1:NDIM,jlo:jhi) = iend(1:NDIM,box(jlo:jhi))
-
-            where (lencounterj(jlo:jhi))
-               where (iend_box(2,jlo:jhi) > ibegi(2))
-                  where (ibeg_box(2,jlo:jhi) < iendi(2))
-                     where (iend_box(3,jlo:jhi) > ibegi(3))
-                        lencounterj(jlo:jhi) = (ibeg_box(3,jlo:jhi) < iendi(3))
-                     end where
-                  end where
-               end where
-            end where
+            call timer2%stop()
+
+            call timer3%start()
+            ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))
+            iendy(jlo:jhi) = iend(2,box(jlo:jhi))
+            ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
+            iendz(jlo:jhi) = iend(3,box(jlo:jhi))
+            call timer3%stop()
+
+            call timer4%start()
+            lencounterj(jlo:jhi) = lencounterj(jlo:jhi) .and. (iendy(jlo:jhi) > ibegi(2)) &
+                                                        .and. (ibegy(jlo:jhi) < iendi(2)) &
+                                                        .and. (iendz(jlo:jhi) > ibegi(3)) &
+                                                        .and. (ibegz(jlo:jhi) < iendi(3))
             
+            call timer4%stop()
+            call timer5%start()
             do concurrent(jbox = jlo:jhi)
                lencounteri(box(jbox)) = lencounterj(jbox)
             end do
+            call timer5%stop()
             
             return
          end subroutine sweep_dl
@@ -1171,7 +1207,8 @@ pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             integer(I4B) :: j, jbox, dim, jlo, jhi
             integer(I4B), dimension(ibegi(1):iendi(1)) :: box
             logical, dimension(ibegi(1):iendi(1)) :: lencounterj
-            integer(I4B), dimension(NDIM, ibegi(1):iendi(1)) :: iend_box, ibeg_box
+            integer(I4B), dimension(ibegi(1):iendi(1)) :: iendy, ibegy
+            integer(I4B), dimension(ibegi(1):iendi(1)) :: iendz, ibegz
 
             jlo = ibegi(1)
             jhi = iendi(1)
@@ -1184,16 +1221,15 @@ pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
                box(:) = box(:) - n
             endwhere
 
-            ibeg_box(:,jlo:jhi) = ibeg(:,box(jlo:jhi))
-            iend_box(:,jlo:jhi) = iend(:,box(jlo:jhi))
+            ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))
+            iendy(jlo:jhi) = iend(2,box(jlo:jhi))
+            ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
+            iendz(jlo:jhi) = iend(3,box(jlo:jhi))
 
-            where (iend_box(2,jlo:jhi) > ibegi(2))
-               where (ibeg_box(2,jlo:jhi) < iendi(2))
-                  where (iend_box(3,jlo:jhi) > ibegi(3))
-                     lencounterj(jlo:jhi) = (ibeg_box(3,jlo:jhi) < iendi(3))
-                  end where
-               end where
-            end where
+            lencounterj(jlo:jhi) = lencounterj(jlo:jhi) .and. (iendy(jlo:jhi) > ibegi(2)) &
+                                                        .and. (ibegy(jlo:jhi) < iendi(2)) &
+                                                        .and. (iendz(jlo:jhi) > ibegi(3)) &
+                                                        .and. (ibegz(jlo:jhi) < iendi(3)) 
 
             do concurrent(jbox = jlo:jhi)
                lencounteri(box(jbox)) = lencounterj(jbox)

From 5df4bc409fad990990d39b5e88960d05b6e2001f Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Wed, 17 Nov 2021 12:43:20 -0500
Subject: [PATCH 06/24] Fixed bad boolean operation resulting from copying the
 double list version of the sweep function to the single list version

---
 src/encounter/encounter_check.f90 | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 14e666855..4fc06b559 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -1226,10 +1226,10 @@ pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
             iendz(jlo:jhi) = iend(3,box(jlo:jhi))
 
-            lencounterj(jlo:jhi) = lencounterj(jlo:jhi) .and. (iendy(jlo:jhi) > ibegi(2)) &
-                                                        .and. (ibegy(jlo:jhi) < iendi(2)) &
-                                                        .and. (iendz(jlo:jhi) > ibegi(3)) &
-                                                        .and. (ibegz(jlo:jhi) < iendi(3)) 
+            lencounterj(jlo:jhi) =       iendy(jlo:jhi) > ibegi(2) &
+                                   .and. (ibegy(jlo:jhi) < iendi(2)) &
+                                   .and. (iendz(jlo:jhi) > ibegi(3)) &
+                                   .and. (ibegz(jlo:jhi) < iendi(3)) 
 
             do concurrent(jbox = jlo:jhi)
                lencounteri(box(jbox)) = lencounterj(jbox)

From 6aaa4a63f5b2ca525ecb014221bc1b5f8e67922e Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Wed, 17 Nov 2021 12:44:04 -0500
Subject: [PATCH 07/24] Added parens for consistency

---
 src/encounter/encounter_check.f90 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 4fc06b559..6e5e11c88 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -1226,7 +1226,7 @@ pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
             iendz(jlo:jhi) = iend(3,box(jlo:jhi))
 
-            lencounterj(jlo:jhi) =       iendy(jlo:jhi) > ibegi(2) &
+            lencounterj(jlo:jhi) =       (iendy(jlo:jhi) > ibegi(2)) &
                                    .and. (ibegy(jlo:jhi) < iendi(2)) &
                                    .and. (iendz(jlo:jhi) > ibegi(3)) &
                                    .and. (ibegz(jlo:jhi) < iendi(3)) 

From fc37e042c2f43b6a5cb7c685a19c9a5b0583a11d Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Wed, 17 Nov 2021 12:53:17 -0500
Subject: [PATCH 08/24] Consolidated box index creation and endpoint index
 shift operations

---
 src/encounter/encounter_check.f90 | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 6e5e11c88..749252d54 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -1112,10 +1112,11 @@ subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencount
 
             lencounteri(:) = .false.
             lencounterj(jlo:jhi) = .false.
-            box(:) = ext_ind(jlo:jhi)
 
-            where(box(jlo:jhi) > ntot)
-               box(jlo:jhi) = box(jlo:jhi) - ntot
+            where(ext_ind(jlo:jhi) > ntot)
+               box(jlo:jhi) = ext_ind(jlo:jhi) - ntot
+            elsewhere
+               box(jlo:jhi) = ext_ind(jlo:jhi)
             endwhere
 
             call timer1%stop()
@@ -1215,10 +1216,11 @@ pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
 
             lencounteri(:) = .false.
             lencounterj(jlo:jhi) = .false.
-            box(:) = ext_ind(jlo:jhi)
 
-            where(box(:) > n)
-               box(:) = box(:) - n
+            where(ext_ind(jlo:jhi) > n)
+               box(jlo:jhi) = ext_ind(jlo:jhi) - n
+            elsewhere
+               box(jlo:jhi) = ext_ind(jlo:jhi)
             endwhere
 
             ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))

From 95d55d4840e07e1e0fdf52faeead7a355406a615 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Wed, 17 Nov 2021 17:49:06 -0500
Subject: [PATCH 09/24] More refinements to sweep algorithm for efficiency and
 parallel performance

---
 src/encounter/encounter_check.f90 | 123 +++++++++++++-----------------
 src/modules/encounter_classes.f90 |   2 +-
 2 files changed, 52 insertions(+), 73 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 749252d54..3e5190dae 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -139,12 +139,14 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       class(swiftest_parameters), allocatable :: tmp_param     !! Temporary parameter structure to turn off adaptive timer for the pl-pl phase if necessary
       integer(I4B), dimension(:), allocatable :: itmp, ind
       logical, dimension(:), allocatable :: ltmp
+      type(walltimer), save :: timer
 
       if (param%ladaptive_encounters_plpl .and. (.not. skipit)) then
          npl = nplm + nplt
          nplplm = nplm * npl - nplm * (nplm + 1) / 2 
          if (nplplm > 0) then
             if (lfirst) then  
+               call timer%reset()
                write(itimer%loopname, *) "encounter_check_all_plpl"
                write(itimer%looptype, *) "ENCOUNTER_PLPL"
                lfirst = .false.
@@ -162,6 +164,7 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       ! Turn off adaptive encounter checks for the pl-pl group
       tmp_param%ladaptive_encounters_plpl = .false.
 
+      call timer%start()
       ! Start with the pl-pl group
       call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, lvdotr, index1, index2, nenc)
 
@@ -171,6 +174,9 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_lvdotr, plmplt_index1, plmplt_index2, plmplt_nenc) 
       end if
 
+      call timer%stop()
+      call timer%report(nsubsteps=1, message="encounter check :")
+
       if (skipit) then
          skipit = .false.
       else
@@ -973,7 +979,7 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
       ! This will build a ragged pair of index lists inside of the lenc data structure
       call encounter_check_sweep_aabb_all_double_list(n1, n2, self%aabb(1)%ind(:), reshape(ibeg(:), [SWEEPDIM, ntot]), reshape(iend(:), [SWEEPDIM, ntot]), ind_arr(:), lenc(:))
       call sweep_timer%stop()
-      call sweep_timer%report(nsubsteps=1, message="double sweep    (total / total per thread):")
+      call sweep_timer%report(nsubsteps=1, message="double sweep    :")
       
       call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2)
 
@@ -1043,49 +1049,42 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
       type(encounter_list), dimension(:),   intent(inout) :: lenc       !! Encounter list for the ith body   
       ! Internals
       integer(I4B) :: i, ntot
-      logical, dimension(n1+n2) :: lencounteri
+      logical, dimension(n1+n2) :: lencounteri, loverlap
       integer(I4B), dimension(SWEEPDIM) :: ibegi, iendi
       type(walltimer), save :: timer1, timer2, timer3, timer4, timer5
-      logical, save :: lfirst=.true.
+      integer(I4B), dimension(:), allocatable :: ext_ind_true
 
-      if (lfirst) then
-         call timer1%reset()
-         call timer2%reset()
-         call timer3%reset()
-         call timer4%reset()
-         call timer5%reset()
-         lfirst = .false.
-      end if     
-      
       ntot = n1 + n2
-      !!$omp parallel do default(private) schedule(dynamic)&
-      !!$omp shared(ext_ind, ibeg, iend, ind_arr, lenc) &
-      !!$omp firstprivate(ntot, n1, n2) 
+      allocate(ext_ind_true, mold=ext_ind)
+      where(ext_ind(:) > ntot)
+         ext_ind_true(:) = ext_ind(:) - ntot
+      elsewhere
+         ext_ind_true(:) = ext_ind(:)
+      endwhere
+
+      loverlap(:) = (iend(1,:) + 1) > (ibeg(1,:) - 1)
+      where(.not.loverlap(:)) lenc(:)%nenc = 0
+      
+      !$omp parallel do default(private) schedule(static)&
+      !$omp shared(ext_ind_true, ibeg, iend, ind_arr, lenc, loverlap) &
+      !$omp firstprivate(ntot, n1, n2) 
       do i = 1,ntot
-         ibegi(1) = ibeg(1,i) + 1
-         iendi(1) = iend(1,i) - 1
-         if (iendi(1) >= ibegi(1)) then
+         if (loverlap(i)) then
+            ibegi(1) = ibeg(1,i) + 1
+            iendi(1) = iend(1,i) - 1
             ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
             iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            call sweep_dl(i, n1, n2, ntot, ext_ind(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
+            call sweep_dl(i, n1, n2, ntot, ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
             call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), lenc(i)%nenc, lenc(i)%index2)
-         else
-            lenc(i)%nenc = 0
          end if
       end do
-      !!$omp end parallel do
-
-      call timer1%report(nsubsteps=1, message="timer1          (total / total per thread):")
-      call timer2%report(nsubsteps=1, message="timer2          (total / total per thread):")
-      call timer3%report(nsubsteps=1, message="timer3          (total / total per thread):")
-      call timer4%report(nsubsteps=1, message="timer4          (total / total per thread):")
-      call timer5%report(nsubsteps=1, message="timer5          (total / total per thread):")
+      !$omp end parallel do
 
       return
 
       contains
 
-         subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
+         pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             !! author: David A. Minton
             !!
             !! Performs a sweep operation on a single body. Encounters from the same lists not allowed (e.g. pl-tp encounters only)
@@ -1106,49 +1105,25 @@ subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencount
             integer(I4B), dimension(ibegi(1):iendi(1)) :: iendy, ibegy
             integer(I4B), dimension(ibegi(1):iendi(1)) :: iendz, ibegz
 
-            call timer1%start()
             jlo = ibegi(1)
             jhi = iendi(1)
 
             lencounteri(:) = .false.
             lencounterj(jlo:jhi) = .false.
-
-            where(ext_ind(jlo:jhi) > ntot)
-               box(jlo:jhi) = ext_ind(jlo:jhi) - ntot
-            elsewhere
-               box(jlo:jhi) = ext_ind(jlo:jhi)
-            endwhere
-
-            call timer1%stop()
-
-            call timer2%start()
-            ! only pairs from the two different lists allowed
-            where (box(jlo:jhi) > n1)
-               lencounterj(jlo:jhi) = (i <= n1)
-            elsewhere
-               lencounterj(jlo:jhi) = (i > n1)
-            end where
-            call timer2%stop()
-
-            call timer3%start()
+            
+            box(jlo:jhi) = ext_ind(jlo:jhi)
+            
             ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))
             iendy(jlo:jhi) = iend(2,box(jlo:jhi))
             ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
             iendz(jlo:jhi) = iend(3,box(jlo:jhi))
-            call timer3%stop()
-
-            call timer4%start()
+            
             lencounterj(jlo:jhi) = lencounterj(jlo:jhi) .and. (iendy(jlo:jhi) > ibegi(2)) &
                                                         .and. (ibegy(jlo:jhi) < iendi(2)) &
                                                         .and. (iendz(jlo:jhi) > ibegi(3)) &
                                                         .and. (ibegz(jlo:jhi) < iendi(3))
             
-            call timer4%stop()
-            call timer5%start()
-            do concurrent(jbox = jlo:jhi)
-               lencounteri(box(jbox)) = lencounterj(jbox)
-            end do
-            call timer5%stop()
+            where (lencounterj(jlo:jhi)) lencounteri(box(jlo:jhi)) = .true. 
             
             return
          end subroutine sweep_dl
@@ -1168,23 +1143,31 @@ subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, in
       type(encounter_list), dimension(:),   intent(inout) :: lenc       !! Encounter list for the ith body   
       ! Internals
       integer(I4B) :: i
-      logical, dimension(n) :: lencounteri
+      logical, dimension(n) :: lencounteri, loverlap
       integer(I4B), dimension(SWEEPDIM) :: ibegi, iendi
+      integer(I4B), dimension(:), allocatable :: ext_ind_true
 
-      !$omp parallel do default(private) schedule(dynamic)&
-      !$omp shared(ext_ind, ibeg, iend, ind_arr, lenc) &
+      allocate(ext_ind_true, mold=ext_ind)
+      where(ext_ind(:) > n)
+         ext_ind_true(:) = ext_ind(:) - n
+      elsewhere
+         ext_ind_true(:) = ext_ind(:)
+      endwhere
+
+      loverlap(:) = (iend(1,:) + 1) > (ibeg(1,:) - 1)
+      where(.not.loverlap(:)) lenc(:)%nenc = 0
+      !$omp parallel do default(private) schedule(static)&
+      !$omp shared(ext_ind_true, ibeg, iend, ind_arr, lenc, loverlap) &
       !$omp firstprivate(n) &
       !$omp lastprivate(ibegi, iendi, lencounteri) 
       do i = 1, n
-         ibegi(1) = ibeg(1,i) + 1
-         iendi(1) = iend(1,i) - 1
-         if (iendi(1) >= ibegi(1)) then
+         if (loverlap(i)) then
+            ibegi(1) = ibeg(1,i) + 1
+            iendi(1) = iend(1,i) - 1
             ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
             iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            call sweep_sl(n, ext_ind(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
+            call sweep_sl(n, ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
             call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), lenc(i)%nenc, lenc(i)%index2)
-         else
-            lenc(i)%nenc = 0
          end if
       end do
       !$omp end parallel do
@@ -1217,11 +1200,7 @@ pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
             lencounteri(:) = .false.
             lencounterj(jlo:jhi) = .false.
 
-            where(ext_ind(jlo:jhi) > n)
-               box(jlo:jhi) = ext_ind(jlo:jhi) - n
-            elsewhere
-               box(jlo:jhi) = ext_ind(jlo:jhi)
-            endwhere
+            box(jlo:jhi) = ext_ind(jlo:jhi)
 
             ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))
             iendy(jlo:jhi) = iend(2,box(jlo:jhi))
diff --git a/src/modules/encounter_classes.f90 b/src/modules/encounter_classes.f90
index 1c182619b..e9959316b 100644
--- a/src/modules/encounter_classes.f90
+++ b/src/modules/encounter_classes.f90
@@ -35,7 +35,7 @@ module encounter_classes
 
    type encounter_bounding_box_1D
       integer(I4B)                            :: n    !! Number of bodies with extents
-      integer(I4B), dimension(:), allocatable :: ind  !! Sorted minimum/maximum extent indices
+      integer(I4B), dimension(:), allocatable :: ind  !! Sorted minimum/maximum extent indices (value > n indicates an ending index)
       integer(I4B), dimension(:), allocatable :: ibeg !! Beginning index for box
       integer(I4B), dimension(:), allocatable :: iend !! Ending index for box
    contains

From 393cd4a68ce733047798b336cb721c8241898727 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Wed, 17 Nov 2021 17:54:07 -0500
Subject: [PATCH 10/24] Removed timers

---
 src/encounter/encounter_check.f90 | 16 ----------------
 1 file changed, 16 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 3e5190dae..ae431b9c8 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -164,7 +164,6 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       ! Turn off adaptive encounter checks for the pl-pl group
       tmp_param%ladaptive_encounters_plpl = .false.
 
-      call timer%start()
       ! Start with the pl-pl group
       call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, lvdotr, index1, index2, nenc)
 
@@ -174,9 +173,6 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_lvdotr, plmplt_index1, plmplt_index2, plmplt_nenc) 
       end if
 
-      call timer%stop()
-      call timer%report(nsubsteps=1, message="encounter check :")
-
       if (skipit) then
          skipit = .false.
       else
@@ -959,13 +955,6 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
       type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I4B), dimension(SWEEPDIM * (n1 + n2)) :: ibeg, iend
-      type(walltimer), save :: sweep_timer
-      logical, save :: lfirst=.true.
-
-      if (lfirst) then
-         call sweep_timer%reset()
-         lfirst = .false.
-      end if
 
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
@@ -974,12 +963,9 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
          iend((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%iend(i)
       end do
 
-      call sweep_timer%start()
       ! Sweep the intervals for each of the massive bodies along one dimension
       ! This will build a ragged pair of index lists inside of the lenc data structure
       call encounter_check_sweep_aabb_all_double_list(n1, n2, self%aabb(1)%ind(:), reshape(ibeg(:), [SWEEPDIM, ntot]), reshape(iend(:), [SWEEPDIM, ntot]), ind_arr(:), lenc(:))
-      call sweep_timer%stop()
-      call sweep_timer%report(nsubsteps=1, message="double sweep    :")
       
       call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2)
 
@@ -1010,7 +996,6 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, nenc, index1,
       Integer(I4B) :: i, k, dim
       type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
-      type(walltimer) :: timer 
       integer(I4B), dimension(SWEEPDIM * n) :: ibeg, iend
 
       call util_index_array(ind_arr, n)
@@ -1051,7 +1036,6 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
       integer(I4B) :: i, ntot
       logical, dimension(n1+n2) :: lencounteri, loverlap
       integer(I4B), dimension(SWEEPDIM) :: ibegi, iendi
-      type(walltimer), save :: timer1, timer2, timer3, timer4, timer5
       integer(I4B), dimension(:), allocatable :: ext_ind_true
 
       ntot = n1 + n2

From 1b2a17fa58d9eab459ebef50f56c22bb7c08467d Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Mon, 22 Nov 2021 15:13:50 -0500
Subject: [PATCH 11/24] Updated integer variables involved in tracking number
 of encoutners to be 8-byte. Restructured the double-list version of the
 sort-sweep algorithm to remove some inefficiencies. Timers still active, so
 this is not production ready.

---
 src/encounter/encounter_check.f90   | 577 +++++++++++++++++++---------
 src/encounter/encounter_setup.f90   |   4 +-
 src/encounter/encounter_util.f90    |  12 +-
 src/modules/encounter_classes.f90   |  32 +-
 src/modules/swiftest_classes.f90    |  20 +
 src/modules/symba_classes.f90       |   2 +-
 src/rmvs/rmvs_encounter_check.f90   |   7 +-
 src/symba/symba_encounter_check.f90 |  13 +-
 src/symba/symba_setup.f90           |   6 +-
 src/symba/symba_step.f90            |   3 +-
 src/symba/symba_util.f90            |  22 +-
 src/util/util_sort.f90              | 162 +++++++-
 12 files changed, 621 insertions(+), 239 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index ae431b9c8..ac6d71d38 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -10,7 +10,7 @@ module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc
       !!
       implicit none
       ! Arguments
-      integer(I4B),                 intent(in)  :: nenc       !! Number of encounters in the encounter lists
+      integer(I8B),                 intent(in)  :: nenc       !! Number of encounters in the encounter lists
       integer(I4B), dimension(:),   intent(in)  :: index1     !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:),   intent(in)  :: index2     !! List of indices for body 2 in each encounter1
       real(DP),     dimension(:,:), intent(in)  :: x1, v1     !! Array of indices of bodies 1
@@ -21,13 +21,14 @@ module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc
       logical,      dimension(:),   intent(out) :: lencounter !! Logical array indicating which pairs are in a close encounter state
       logical,      dimension(:),   intent(out) :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
-      integer(I4B) :: i, j, k
+      integer(I4B) :: i, j
+      integer(I8B) :: k
       real(DP)     :: xr, yr, zr, vxr, vyr, vzr, renc12
 
       !$omp parallel do simd default(firstprivate) schedule(static)&
       !$omp shared(lencounter, lvdotr, index1, index2, x1, v1, x2, v2) &
       !$omp lastprivate(i, j, xr, yr, zr, vxr, vyr, vzr, renc12)
-      do k = 1, nenc
+      do k = 1_I8B, nenc
          i = index1(k)
          j = index2(k)
          xr = x2(1, j) - x1(1, i)
@@ -61,7 +62,7 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, lvdotr, i
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out)   :: nenc   !! Total number of encounters
+      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       ! Internals
       type(interaction_timer), save :: itimer
       logical, save :: lfirst = .true.
@@ -125,19 +126,21 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out)   :: nenc   !! Total number of encounters
+      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       ! Internals
       type(interaction_timer), save :: itimer
       logical, save :: lfirst = .true.
       logical, save :: skipit = .false.
       integer(I8B) :: nplplm = 0_I8B
       integer(I4B) :: npl, i
+      integer(I8B) :: k
       logical,      dimension(:), allocatable :: plmplt_lvdotr !! Logical flag indicating the sign of v .dot. x in the plm-plt group
       integer(I4B), dimension(:), allocatable :: plmplt_index1 !! List of indices for body 1 in each encounter in the plm-plt group
       integer(I4B), dimension(:), allocatable :: plmplt_index2 !! List of indices for body 2 in each encounter in the plm-lt group
-      integer(I4B)                            :: plmplt_nenc   !! Number of encounters of the plm-plt group
+      integer(I8B)                            :: plmplt_nenc   !! Number of encounters of the plm-plt group
       class(swiftest_parameters), allocatable :: tmp_param     !! Temporary parameter structure to turn off adaptive timer for the pl-pl phase if necessary
-      integer(I4B), dimension(:), allocatable :: itmp, ind
+      integer(I8B), dimension(:), allocatable :: ind
+      integer(I4B), dimension(:), allocatable :: itmp
       logical, dimension(:), allocatable :: ltmp
       type(walltimer), save :: timer
 
@@ -165,6 +168,7 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       tmp_param%ladaptive_encounters_plpl = .false.
 
       ! Start with the pl-pl group
+      call timer%start()
       call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, lvdotr, index1, index2, nenc)
 
       if (param%lencounter_sas_plpl) then
@@ -172,6 +176,8 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       else
          call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_lvdotr, plmplt_index1, plmplt_index2, plmplt_nenc) 
       end if
+      call timer%stop()
+      call timer%report(nsubsteps=1, message="Encounter check  :")
 
       if (skipit) then
          skipit = .false.
@@ -199,10 +205,17 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call move_alloc(ltmp, lvdotr)
          nenc = nenc + plmplt_nenc
 
-         call util_sort(index1, itmp)
-         call util_sort_rearrange(index1, itmp, nenc)
-         call util_sort_rearrange(index2, itmp, nenc)
-         call util_sort_rearrange(lvdotr, itmp, nenc)
+         call util_sort(index1, ind)
+         call util_sort_rearrange(index1, ind, nenc)
+         call util_sort_rearrange(index2, ind, nenc)
+         call util_sort_rearrange(lvdotr, ind, nenc)
+
+         ! TEMP FOR TESTING
+         open(unit=22,file="enclist.csv", status="replace")
+         do k = 1_I8B, nenc
+            write(22,*) index1(k), index2(k)
+         end do
+         close(22)
       end if
 
       return
@@ -228,7 +241,7 @@ module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp,
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out)   :: nenc   !! Total number of encounters
+      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       ! Internals
       type(interaction_timer), save :: itimer
       logical, save :: lfirst = .true.
@@ -271,23 +284,24 @@ module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp,
    end subroutine encounter_check_all_pltp
 
 
-   subroutine encounter_check_reduce_broadphase(n, nenc, index1, index2, lencounter, lvdotr)
+   pure subroutine encounter_check_reduce_broadphase(n, nenc, index1, index2, lencounter, lvdotr)
       !! author: David A. Minton
       !!
       !! Takes the candidate encounter lists that came out of the broad phase and narrow it down to the true encounters
       implicit none
       ! Arguments
       integer(I4B),                            intent(in)    :: n          !! Number of bodies 
-      integer(I4B),                            intent(inout) :: nenc       !! Number of encountering bodies (input is the broad phase value, output is the final narrow phase value)
+      integer(I8B),                            intent(inout) :: nenc       !! Number of encountering bodies (input is the broad phase value, output is the final narrow phase value)
       integer(I4B), dimension(:), allocatable, intent(inout) :: index1     !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(inout) :: index2     !! List of indices for body 2 in each encounter
       logical,      dimension(:), allocatable, intent(inout) :: lencounter !! Logical flag indicating which of the pairs identified in the broad phase was selected in the narrow phase
       logical,      dimension(:), allocatable, intent(inout) :: lvdotr     !! Logical flag indicating the sign of v .dot. x
       ! Internals
-      integer(I4B) :: i, i0, j, k, nenci, klo, khi
+      integer(I4B) :: i, i0, j
+      integer(I8B) :: k, klo, khi, nenci
       integer(I4B), dimension(:), allocatable :: itmp
-      integer(I4B), dimension(:), allocatable :: ind
-      integer(I4B), dimension(n) :: ibeg, iend
+      integer(I8B), dimension(:), allocatable :: ind
+      integer(I8B), dimension(n) :: ibeg, iend
       logical, dimension(:), allocatable :: ltmp
 
       nenc = count(lencounter(:)) ! Count the true number of encounters
@@ -298,21 +312,23 @@ subroutine encounter_check_reduce_broadphase(n, nenc, index1, index2, lencounter
          return
       end if
 
-      allocate(itmp(nenc))
-      itmp(:) = pack(index1(:), lencounter(:))
-      call move_alloc(itmp, index1)
+      if (any(.not.lencounter(:))) then
+         allocate(itmp(nenc))
+         itmp(:) = pack(index1(:), lencounter(:))
+         call move_alloc(itmp, index1)
 
-      allocate(itmp(nenc))
-      itmp(:) = pack(index2(:), lencounter(:))
-      call move_alloc(itmp, index2)
+         allocate(itmp(nenc))
+         itmp(:) = pack(index2(:), lencounter(:))
+         call move_alloc(itmp, index2)
 
-      allocate(ltmp(nenc))
-      ltmp(:) = pack(lvdotr(:), lencounter(:))
-      call move_alloc(ltmp, lvdotr)
+         allocate(ltmp(nenc))
+         ltmp(:) = pack(lvdotr(:), lencounter(:))
+         call move_alloc(ltmp, lvdotr)
 
-      if (allocated(lencounter)) deallocate(lencounter)
-      allocate(lencounter(nenc))
-      lencounter(:) = .true.
+         if (allocated(lencounter)) deallocate(lencounter)
+         allocate(lencounter(nenc))
+         lencounter(:) = .true.
+      end if
 
       call util_sort(index1, ind)
       call util_sort_rearrange(index1, ind, nenc)
@@ -386,7 +402,7 @@ subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, lvdotr,
       logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out) :: nenc   !! Total number of encounters
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
       ! Internals
       integer(I4B) :: i, dim, n
       integer(I4B), save :: npl_last = 0
@@ -422,7 +438,7 @@ subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, lvdotr,
 
       call boundingbox%sweep(npl, nenc, index1, index2)
 
-      if (nenc > 0) then
+      if (nenc > 0_I8B) then
          ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
          allocate(lencounter(nenc))
          allocate(lvdotr(nenc))
@@ -458,7 +474,7 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
       logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out) :: nenc   !! Total number of encounter
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounter
       ! Internals
       type(encounter_bounding_box), save :: boundingbox
       integer(I4B) :: i, dim, n, ntot
@@ -505,24 +521,221 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
       end do
       !$omp end parallel do
 
-      call boundingbox%sweep(nplm, nplt, nenc, index1, index2)
+      call encounter_check_sweep_aabb_double_list_2(boundingbox, nplm, nplt, nenc, index1, index2, xplm, vplm, xplt, vplt, rencm, renct, dt, lvdotr) 
 
-      if (nenc > 0) then
-         ! Shift tiny body indices back into the range of the input position and velocity arrays
-         index2(:) = index2(:) - nplm
+      !call boundingbox%sweep(nplm, nplt, nenc, index1, index2)
 
-         ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
-         allocate(lencounter(nenc))
-         allocate(lvdotr(nenc))
+      ! if (nenc > 0_I8B) then
+      !    ! Shift tiny body indices back into the range of the input position and velocity arrays
+      !    !index2(:) = index2(:) - nplm
 
-         call encounter_check_all(nenc, index1, index2, xplm, vplm, xplt, vplt, rencm, renct, dt, lencounter, lvdotr)
+      !    ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
+      !    allocate(lencounter(nenc))
+      !    allocate(lvdotr(nenc))
 
-         call encounter_check_reduce_broadphase(ntot, nenc, index1, index2, lencounter, lvdotr)
-      end if
+      !    call encounter_check_all(nenc, index1, index2, xplm, vplm, xplt, vplt, rencm, renct, dt, lencounter, lvdotr)
+
+      !    call encounter_check_reduce_broadphase(ntot, nenc, index1, index2, lencounter, lvdotr)
+      ! end if
       return
    end subroutine encounter_check_all_sort_and_sweep_plplm
 
 
+   subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1, index2, x1, v1, x2, v2, renc1, renc2, dt, lvdotr)
+      !! author: David A. Minton
+      !!
+      !! Sweeps the sorted bounding box extents and returns the true encounters (combines broad and narrow phases)
+      implicit none
+      ! Arguments
+      class(encounter_bounding_box),           intent(inout) :: self       !! Multi-dimensional bounding box structure
+      integer(I4B),                            intent(in)    :: n1         !! Number of bodies 1
+      integer(I4B),                            intent(in)    :: n2         !! Number of bodies 2
+      integer(I8B),                            intent(out)   :: nenc       !! Total number of encounter candidates
+      integer(I4B), dimension(:), allocatable, intent(out)   :: index1     !! List of indices for body 1 in each encounter candidate pair
+      integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for body 2 in each encounter candidate pair
+      real(DP),     dimension(:,:),            intent(in)    :: x1, v1     !! Array of indices of bodies 1
+      real(DP),     dimension(:,:),            intent(in)    :: x2, v2     !! Array of indices of bodies 2
+      real(DP),     dimension(:),              intent(in)    :: renc1      !! Radius of encounter regions of bodies 1
+      real(DP),     dimension(:),              intent(in)    :: renc2      !! Radius of encounter regions of bodies 2
+      real(DP),                                intent(in)    :: dt         !! Step size
+      logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
+      ! Internals
+      integer(I4B) :: ii, i, j, jj, ntot, dim
+      integer(I8B) :: k, kk, nbox
+      logical, dimension(n1+n2) :: lencounteri, loverlap
+      logical, dimension(:), allocatable  :: lencounter, lvdotri
+      logical, dimension(:), allocatable :: lencounterj, lenctrue, ltmp, llist1
+      integer(I4B), dimension(:), allocatable :: ext_ind_true
+      type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
+      integer(I4B), dimension(:), allocatable, save :: ind_arr
+      integer(I8B) :: ibegix, iendix
+      integer(I8B), pointer :: ibegx, ibegy
+      integer(I4B), dimension(:), allocatable :: index1i, index2i, itmp
+      type(walltimer) :: timer1, timer2, timer3, timer4, timer5
+      logical, save :: lfirst = .true.
+
+      if (lfirst) then
+         call timer1%reset()
+         call timer2%reset()
+         call timer3%reset()
+         call timer4%reset()
+         call timer5%reset()
+         lfirst = .false.
+      end if
+
+      ntot = n1 + n2
+      call util_index_array(ind_arr, ntot)
+
+      associate(ext_ind => self%aabb(1)%ind(:), ibegx => self%aabb(1)%ibeg(:), iendx => self%aabb(1)%iend(:))
+         ! Sweep the intervals for each of the massive bodies along one dimension
+         ! This will build a ragged pair of index lists inside of the lenc data structure
+         allocate(ext_ind_true, mold=ext_ind)
+         allocate(llist1(size(ext_ind)))
+         where(ext_ind(:) > ntot)
+            ext_ind_true(:) = ext_ind(:) - ntot
+         elsewhere
+            ext_ind_true(:) = ext_ind(:)
+         endwhere
+         llist1(:) = ext_ind_true(:) <= n1
+
+         loverlap(:) = (iendx(:) + 1) > (ibegx(:) - 1)
+         where(.not.loverlap(:)) lenc(:)%nenc = 0
+         
+         call timer1%start()
+         !$omp parallel do default(private) schedule(static)&
+         !$omp shared(ext_ind_true, ibegx, iendx, ind_arr, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
+         !$omp firstprivate(ntot, n1, dt) 
+         do i = 1, ntot
+            if (loverlap(i)) then
+               ibegix = ibegx(i) + 1_I8B
+               iendix = iendx(i) - 1_I8B
+               call timer2%start()
+               if (i <= n1) then
+                  lenc(i)%nenc = count(.not.llist1(ibegix:iendix))
+               else
+                  lenc(i)%nenc = count(llist1(ibegix:iendix))
+               end if
+               call timer2%stop()
+               if (lenc(i)%nenc > 0_I8B) then
+                  ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
+                  call timer3%start()
+                  nbox = iendix - ibegix + 1_I8B
+                  if (allocated(lenctrue)) deallocate(lenctrue); allocate(lenctrue(nbox))
+                  if (allocated(lvdotri)) deallocate(lvdotri); allocate(lvdotri(nbox))
+                  if (allocated(index1i)) deallocate(index1i); allocate(index1i(nbox))
+                  if (allocated(index2i)) deallocate(index2i); allocate(index2i(nbox))
+                  lenctrue(:) = .false.
+                  lvdotri(:) = .false.
+                  call timer3%stop()
+
+                  call timer4%start()
+                  if (i <= n1) then
+                     do concurrent(k=ibegix:iendix, .not.llist1(k))
+                        kk = k - ibegix + 1_I8B
+                        ii = i
+                        jj = ext_ind_true(k) - n1
+                        index1i(kk) = ii
+                        index2i(kk) = jj
+                     end do
+                     do concurrent(kk=1:nbox, .not.llist1(kk+ibegix-1_I8B))
+                        ii = index1i(kk)
+                        jj = index2i(kk)
+                        call encounter_check_sweep_check_one(x1(1,ii), x1(2,ii), x1(3,ii), &
+                                                             x2(1,jj), x2(2,jj), x2(3,jj), &  
+                                                             v1(1,ii), v1(2,ii), v1(3,ii), &  
+                                                             v2(1,jj), v2(2,jj), v2(3,jj), &  
+                                                             renc1(ii), renc2(jj), dt, &
+                                                             lenctrue(kk), lvdotri(kk))
+                     end do
+                  else
+                     do concurrent(k=ibegix:iendix, llist1(k))
+                        kk = k - ibegix + 1_I8B
+                        ii = ext_ind_true(k)
+                        jj = i - n1
+                        index1i(kk) = ii
+                        index2i(kk) = jj
+                     end do
+                     do concurrent(kk=1:nbox, llist1(kk+ibegix-1_I8B))
+                        ii = index1i(kk)
+                        jj = index2i(kk)
+                        call encounter_check_sweep_check_one(x1(1,ii), x1(2,ii), x1(3,ii), &
+                                                             x2(1,jj), x2(2,jj), x2(3,jj), &  
+                                                             v1(1,ii), v1(2,ii), v1(3,ii), &  
+                                                             v2(1,jj), v2(2,jj), v2(3,jj), &  
+                                                             renc1(ii), renc2(jj), dt, &
+                                                             lenctrue(kk), lvdotri(kk))
+                     end do
+                  end if
+                  call timer4%stop()
+
+                  call timer5%start()
+                  lenc(i)%nenc = count(lenctrue(:))
+                  if (lenc(i)%nenc > 0_I8B) then
+                     allocate(itmp(lenc(i)%nenc))
+                     itmp = pack(index1i(:), lenctrue(:))
+                     call move_alloc(itmp, lenc(i)%index1)
+
+                     allocate(itmp(lenc(i)%nenc))
+                     itmp = pack(index2i(:), lenctrue(:))
+                     call move_alloc(itmp, lenc(i)%index2)
+
+                     allocate(ltmp(lenc(i)%nenc))
+                     ltmp = pack(lvdotri(:), lenctrue(:))
+                     call move_alloc(ltmp, lenc(i)%lvdotr)
+                  end if
+                  call timer5%stop()
+               end if
+            end if
+         end do
+         !$omp end parallel do
+
+         call timer1%stop()
+         call timer1%report(nsubsteps=1, message="timer1           :")
+         call timer2%report(nsubsteps=1, message="timer2           :")
+         call timer3%report(nsubsteps=1, message="timer3           :")
+         call timer4%report(nsubsteps=1, message="timer4           :")
+         call timer5%report(nsubsteps=1, message="timer5           :")
+
+      end associate
+
+      call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2, lvdotr)
+
+      if (allocated(lencounter)) deallocate(lencounter)
+      allocate(lencounter(nenc))
+      lencounter(:) = .true.
+
+      call encounter_check_reduce_broadphase(ntot, nenc, index1, index2, lencounter, lvdotr)
+
+      return
+   end subroutine encounter_check_sweep_aabb_double_list_2
+
+   pure subroutine encounter_check_sweep_check_one(x1,y1,z1,x2,y2,z2,vx1,vy1,vz1,vx2,vy2,vz2,renc1,renc2,dt,lencounter,lvdotr)
+      !$omp declare simd(encounter_check_sweep_check_one)
+      implicit none
+      ! Arguments
+      real(DP), intent(in)  :: x1,y1,z1
+      real(DP), intent(in)  :: x2,y2,z2
+      real(DP), intent(in)  :: vx1,vy1,vz1
+      real(DP), intent(in)  :: vx2,vy2,vz2
+      real(DP), intent(in)  :: renc1, renc2
+      real(DP), intent(in)  :: dt
+      logical,  intent(out) :: lencounter
+      logical,  intent(out) :: lvdotr
+      ! Internals
+      real(DP)  :: renc12,xr, yr, zr, vxr, vyr, vzr
+
+      xr = x2 - x1
+      yr = y2 - y1
+      zr = z2 - z1
+      vxr = vx2 - vx1
+      vyr = vy2 - vy1
+      vzr = vz2 - vz1
+      renc12 = renc1 + renc2
+      call encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc12, dt, lencounter, lvdotr) 
+
+      return
+   end subroutine encounter_check_sweep_check_one
+
    subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc)
       !! author: David A. Minton
       !!
@@ -543,7 +756,7 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
       logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out) :: nenc   !! Total number of encounter
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounter
       ! Internals
       type(encounter_bounding_box), save :: boundingbox
       integer(I4B) :: i, dim, n, ntot
@@ -592,7 +805,7 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
 
       call boundingbox%sweep(npl, ntp, nenc, index1, index2)
 
-      if (nenc > 0) then
+      if (nenc > 0_I8B) then
          ! Shift test particle indices back into the proper range
          index2(:) = index2(:) - npl
 
@@ -626,7 +839,8 @@ pure subroutine encounter_check_all_triangular_one(i, n, xi, yi, zi, vxi, vyi, v
       integer(I4B),         dimension(:), intent(in)  :: ind_arr
       type(encounter_list),               intent(out) :: lenci
       ! Internals
-      integer(I4B) :: j, nenci
+      integer(I4B) :: j
+      integer(I8B) :: k, nenci
       real(DP) :: xr, yr, zr, vxr, vyr, vzr, renc12
       logical, dimension(n) :: lencounteri, lvdotri
 
@@ -641,8 +855,8 @@ pure subroutine encounter_check_all_triangular_one(i, n, xi, yi, zi, vxi, vyi, v
          call encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc12, dt, lencounteri(j), lvdotri(j))
       end do
       nenci = count(lencounteri(i+1:n))
-      if (nenci > 0) then
-         allocate(lenci%lvdotr(nenci), lenci%index2(nenci))
+      if (nenci > 0_I8B) then
+         allocate(lenci%lvdotr(nenci), lenci%index1(nenci), lenci%index2(nenci))
          lenci%nenc = nenci
          lenci%lvdotr(:) = pack(lvdotri(i+1:n), lencounteri(i+1:n)) 
          lenci%index2(:) = pack(ind_arr(i+1:n), lencounteri(i+1:n)) 
@@ -667,7 +881,7 @@ subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, lvdotr, inde
       logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out) :: nenc   !! Total number of encounters
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
       ! Internals
       integer(I4B) :: i, j, k, nenci, j0, j1
       real(DP) :: xr, yr, zr, vxr, vyr, vzr, renc12
@@ -687,6 +901,7 @@ subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, lvdotr, inde
                                                          x(1,:), x(2,:), x(3,:), &
                                                          v(1,:), v(2,:), v(3,:), &
                                                          renc(i), renc(:), dt, ind_arr(:), lenc(i))
+         if (lenc(i)%nenc > 0) lenc(i)%index1(:) = i
       end do
       !$omp end parallel do
 
@@ -715,10 +930,9 @@ subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vp
       logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out) :: nenc   !! Total number of encounters
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
       ! Internals
-      integer(I4B) :: i, j, nenci, j0, j1
-      real(DP) :: xr, yr, zr, vxr, vyr, vzr, renc12
+      integer(I4B) :: i
       logical, dimension(nplt) :: lencounteri, lvdotri
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       type(encounter_list), dimension(nplm) :: lenc
@@ -735,6 +949,7 @@ subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vp
                                                           xplt(1,:), xplt(2,:), xplt(3,:), &
                                                           vplt(1,:), vplt(2,:), vplt(3,:), &
                                                           rencm(i), renct(:), dt, ind_arr(:), lenc(i))
+         if (lenc(i)%nenc > 0) lenc(i)%index1(:) = i
       end do
       !$omp end parallel do
 
@@ -762,10 +977,9 @@ subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, ren
       logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I4B),                            intent(out) :: nenc   !! Total number of encounters
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
       ! Internals
-      integer(I4B) :: i, j, nenci, j0, j1
-      real(DP) :: xr, yr, zr, vxr, vyr, vzr, renc1, renc2
+      integer(I4B) :: i
       logical, dimension(ntp) :: lencounteri, lvdotri
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       type(encounter_list), dimension(npl) :: lenc
@@ -783,6 +997,7 @@ subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, ren
                                                          xtp(1,:), xtp(2,:), xtp(3,:), &
                                                          vtp(1,:), vtp(2,:), vtp(3,:), &
                                                          renc(i), renct(:), dt, ind_arr(:), lenc(i))
+         if (lenc(i)%nenc > 0) lenc(i)%index1(:) = i
       end do
       !$omp end parallel do
 
@@ -847,12 +1062,13 @@ module subroutine encounter_check_collapse_ragged_list(ragged_list, n1, nenc, in
       ! Arguments
       type(encounter_list), dimension(:),              intent(in)            :: ragged_list !! The ragged encounter list
       integer(I4B),                                    intent(in)            :: n1          !! Number of bodies 1
-      integer(I4B),                                    intent(out)           :: nenc        !! Total number of encountersj 
+      integer(I8B),                                    intent(out)           :: nenc        !! Total number of encountersj 
       integer(I4B),         dimension(:), allocatable, intent(out)           :: index1      !! Array of indices for body 1
       integer(I4B),         dimension(:), allocatable, intent(out)           :: index2      !! Array of indices for body 1
       logical,              dimension(:), allocatable, intent(out), optional :: lvdotr      !! Array indicating which bodies are approaching
       ! Internals
-      integer(I4B) :: i, j0, j1, nenci
+      integer(I4B) :: i
+      integer(I8B) :: j1, j0, nenci
       integer(I4B), dimension(n1) :: ibeg
 
       associate(nenc_arr => ragged_list(:)%nenc)
@@ -876,11 +1092,11 @@ module subroutine encounter_check_collapse_ragged_list(ragged_list, n1, nenc, in
       !$omp shared(ragged_list, index1, index2, ibeg, lvdotr) &
       !$omp firstprivate(n1)
       do i = 1,n1
-         if (ragged_list(i)%nenc == 0) cycle
+         if (ragged_list(i)%nenc == 0_I8B) cycle
          nenci = ragged_list(i)%nenc
          j0 = ibeg(i)
-         j1 = j0 + nenci - 1
-         index1(j0:j1) = i
+         j1 = j0 + nenci - 1_I8B
+         index1(j0:j1) = ragged_list(i)%index1(:)
          index2(j0:j1) = ragged_list(i)%index2(:)
          if (present(lvdotr)) lvdotr(j0:j1) = ragged_list(i)%lvdotr(:)
       end do
@@ -890,19 +1106,24 @@ module subroutine encounter_check_collapse_ragged_list(ragged_list, n1, nenc, in
    end subroutine encounter_check_collapse_ragged_list
 
 
-   pure subroutine encounter_check_make_ragged_list(lencounteri, ind_arr, nenc,index2)
+   pure subroutine encounter_check_make_ragged_list(lencounteri, ind_arr, i, lenci)
       implicit none
       ! Arguments
-      logical, dimension(:), intent(in) :: lencounteri
-      integer(I4B), dimension(:), intent(in) :: ind_arr
-      integer(I4B),                            intent(out) :: nenc
-      integer(I4B), dimension(:), allocatable, intent(out) :: index2
+      logical,      dimension(:),              intent(in)  :: lencounteri !! Array of logicals indicating which bodies are candidates for encounter with body i
+      integer(I4B), dimension(:),              intent(in)  :: ind_arr     !! Index array 
+      integer(I4B),                            intent(in)  :: i           !! Index value of body i that will fill index1 
+      type(encounter_list),                    intent(out) :: lenci       !! The ith row of the ragged encounter list
       ! Internals
-
-      nenc = count(lencounteri(:))
-      if (nenc > 0) then
-         allocate(index2(nenc))
-         index2(:) = pack(ind_arr(:), lencounteri(:)) 
+      integer(I8B) :: k
+
+      lenci%nenc = count(lencounteri(:))
+      if (lenci%nenc > 0_I8B) then
+         if (allocated(lenci%index1)) deallocate(lenci%index1)
+         if (allocated(lenci%index2)) deallocate(lenci%index2)
+         allocate(lenci%index1(lenci%nenc))
+         allocate(lenci%index2(lenci%nenc))
+         lenci%index1(:) = [(i, k = 1_I8B, lenci%nenc)]
+         lenci%index2(:) = pack(ind_arr(:), lencounteri(:)) 
       end if
 
       return
@@ -920,12 +1141,12 @@ module pure subroutine encounter_check_sort_aabb_1D(self, n, extent_arr)
       integer(I4B),                     intent(in)    :: n          !! Number of bodies with extents
       real(DP), dimension(:),           intent(in)    :: extent_arr !! Array of extents of size 2*n
       ! Internals
-      integer(I4B) :: i, j, k, ibox, jbox
+      integer(I8B) :: i, k
       logical, dimension(:), allocatable :: lfresh
 
       call util_sort(extent_arr, self%ind)
 
-      do concurrent(k = 1:2*n)
+      do concurrent(k = 1_I8B:2_I8B*n)
          i = self%ind(k)
          if (i <= n) then
             self%ibeg(i) = k
@@ -947,14 +1168,15 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
       class(encounter_bounding_box),           intent(inout) :: self     !! Multi-dimensional bounding box structure
       integer(I4B),                            intent(in)    :: n1       !! Number of bodies 1
       integer(I4B),                            intent(in)    :: n2       !! Number of bodies 2
-      integer(I4B),                            intent(out)   :: nenc     !! Total number of encounter candidates
+      integer(I8B),                            intent(out)   :: nenc     !! Total number of encounter candidates
       integer(I4B), dimension(:), allocatable, intent(out)   :: index1   !! List of indices for body 1 in each encounter candidate pair
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2   !! List of indices for body 2 in each encounter candidate pair
-      !Internals
-      integer(I4B) :: i, k, ntot, dim
+      ! Internals
+      integer(I4B) :: i, ntot, dim
+      integer(I8B) :: k
       type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
-      integer(I4B), dimension(SWEEPDIM * (n1 + n2)) :: ibeg, iend
+      integer(I8B), dimension(SWEEPDIM * (n1 + n2)) :: ibeg, iend
 
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
@@ -970,7 +1192,7 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
       call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2)
 
       ! Reorder the pairs and sort the first index in order to remove any duplicates
-      do concurrent(k = 1:nenc, index2(k) < index1(k))
+      do concurrent(k = 1_I8B:nenc, index2(k) < index1(k))
          i = index2(k)
          index2(k) = index1(k)
          index1(k) = i
@@ -989,14 +1211,15 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, nenc, index1,
       ! Arguments
       class(encounter_bounding_box),           intent(inout) :: self    !! Multi-dimensional bounding box structure
       integer(I4B),                            intent(in)    :: n       !! Number of bodies 1
-      integer(I4B),                            intent(out)   :: nenc    !! Total number of encounter candidates
+      integer(I8B),                            intent(out)   :: nenc    !! Total number of encounter candidates
       integer(I4B), dimension(:), allocatable, intent(out)   :: index1  !! List of indices for body 1 in each encounter candidate pair
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2  !! List of indices for body 2 in each encounter candidate pair
       !Internals
-      Integer(I4B) :: i, k, dim
+      integer(I4B) :: i, dim
+      integer(I8B) :: k
       type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
-      integer(I4B), dimension(SWEEPDIM * n) :: ibeg, iend
+      integer(I8B), dimension(SWEEPDIM * n) :: ibeg, iend
 
       call util_index_array(ind_arr, n)
       do concurrent(dim = 1:SWEEPDIM, i = 1:n)
@@ -1011,7 +1234,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, nenc, index1,
       call encounter_check_collapse_ragged_list(lenc, n, nenc, index1, index2)
 
       ! Reorder the pairs and sort the first index in order to remove any duplicates
-      do concurrent(k = 1:nenc, index2(k) < index1(k))
+      do concurrent(k = 1_I8B:nenc, index2(k) < index1(k))
          i = index2(k)
          index2(k) = index1(k)
          index1(k) = i
@@ -1029,13 +1252,15 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
       ! Arguments
       integer(I4B),                         intent(in)    :: n1, n2     !! Number of bodies
       integer(I4B),         dimension(:),   intent(in)    :: ext_ind    !! Sorted index array of extents
-      integer(I4B),         dimension(:,:), intent(in)    :: ibeg, iend !! Beginning and ending index lists in the n-dimensions
+      integer(I8B),         dimension(:,:), intent(in)    :: ibeg, iend !! Beginning and ending index lists in the n-dimensions
       integer(I4B),         dimension(:),   intent(in)    :: ind_arr    !! index array for mapping body 2 indexes
       type(encounter_list), dimension(:),   intent(inout) :: lenc       !! Encounter list for the ith body   
       ! Internals
-      integer(I4B) :: i, ntot
+      integer(I4B) :: i, j, ntot
+      integer(I8B) :: ibegx, iendx
       logical, dimension(n1+n2) :: lencounteri, loverlap
-      integer(I4B), dimension(SWEEPDIM) :: ibegi, iendi
+      integer(I8B), dimension(SWEEPDIM) :: ibegi, iendi
+      logical, dimension(:), allocatable :: lencounterj
       integer(I4B), dimension(:), allocatable :: ext_ind_true
 
       ntot = n1 + n2
@@ -1049,17 +1274,42 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
       loverlap(:) = (iend(1,:) + 1) > (ibeg(1,:) - 1)
       where(.not.loverlap(:)) lenc(:)%nenc = 0
       
+      lencounteri(:) = .false.
+      !$omp parallel do default(private) schedule(static)&
+      !$omp shared(ext_ind_true, ibeg, iend, ind_arr, lenc, loverlap) &
+      !$omp firstprivate(ntot, n1, lencounteri) 
+      do i = 1,n1
+         if (loverlap(i)) then
+            ibegi(1) = ibeg(1,i) + 1_I8B
+            iendi(1) = iend(1,i) - 1_I8B
+            ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
+            iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
+            allocate(lencounterj(1 + iendi(1) - ibegi(1)))
+            lencounterj(:) = ext_ind_true(ibegi(1):iendi(1)) > n1
+            call sweep_list(ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:), lencounterj(:))
+            deallocate(lencounterj)
+            call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), i, lenc(i))
+            lencounteri(ext_ind_true(ibegi(1):iendi(1))) = .false.
+         end if
+      end do
+      !$omp end parallel do
+
+      lencounteri(:) = .false.
       !$omp parallel do default(private) schedule(static)&
       !$omp shared(ext_ind_true, ibeg, iend, ind_arr, lenc, loverlap) &
-      !$omp firstprivate(ntot, n1, n2) 
-      do i = 1,ntot
+      !$omp firstprivate(n1, n2, lencounteri) 
+      do i = n1+1, n1+n2
          if (loverlap(i)) then
-            ibegi(1) = ibeg(1,i) + 1
-            iendi(1) = iend(1,i) - 1
+            ibegi(1) = ibeg(1,i) + 1_I8B
+            iendi(1) = iend(1,i) - 1_I8B
             ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
             iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            call sweep_dl(i, n1, n2, ntot, ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
-            call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), lenc(i)%nenc, lenc(i)%index2)
+            allocate(lencounterj(1 + iendi(1) - ibegi(1)))
+            lencounterj(:) = ext_ind_true(ibegi(1):iendi(1)) <= n1
+            call sweep_list(ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:), lencounterj(:))
+            deallocate(lencounterj)
+            call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), i, lenc(i))
+            lencounteri(ext_ind_true(ibegi(1):iendi(1))) = .false.
          end if
       end do
       !$omp end parallel do
@@ -1068,49 +1318,6 @@ subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, ien
 
       contains
 
-         pure subroutine sweep_dl(i, n1, n2, ntot, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
-            !! author: David A. Minton
-            !!
-            !! Performs a sweep operation on a single body. Encounters from the same lists not allowed (e.g. pl-tp encounters only)
-            implicit none
-            ! Arguments
-            integer(I4B),                 intent(in)  :: i            !! The current index of the ith body
-            integer(I4B),                 intent(in)  :: n1           !! Number of bodies 1
-            integer(I4B),                 intent(in)  :: n2           !! Number of bodies 2
-            integer(I4B),                 intent(in)  :: ntot         !! n1 + n2
-            integer(I4B), dimension(:),   intent(in)  :: ext_ind      !! Sorted index array of extents
-            integer(I4B), dimension(:),   intent(in)  :: ibegi, iendi !! The beginning and ending indices of the ith bounding box in the n-dimensions
-            integer(I4B), dimension(:,:), intent(in)  :: ibeg, iend   !! Beginning and ending index lists in the n-dimensions
-            logical, dimension(:),        intent(out) :: lencounteri    !! Encounter list for the ith body
-            ! Internals
-            integer(I4B) :: j, jbox, dim, jlo, jhi
-            integer(I4B), dimension(ibegi(1):iendi(1)) :: box
-            logical, dimension(ibegi(1):iendi(1)) :: lencounterj
-            integer(I4B), dimension(ibegi(1):iendi(1)) :: iendy, ibegy
-            integer(I4B), dimension(ibegi(1):iendi(1)) :: iendz, ibegz
-
-            jlo = ibegi(1)
-            jhi = iendi(1)
-
-            lencounteri(:) = .false.
-            lencounterj(jlo:jhi) = .false.
-            
-            box(jlo:jhi) = ext_ind(jlo:jhi)
-            
-            ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))
-            iendy(jlo:jhi) = iend(2,box(jlo:jhi))
-            ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
-            iendz(jlo:jhi) = iend(3,box(jlo:jhi))
-            
-            lencounterj(jlo:jhi) = lencounterj(jlo:jhi) .and. (iendy(jlo:jhi) > ibegi(2)) &
-                                                        .and. (ibegy(jlo:jhi) < iendi(2)) &
-                                                        .and. (iendz(jlo:jhi) > ibegi(3)) &
-                                                        .and. (ibegz(jlo:jhi) < iendi(3))
-            
-            where (lencounterj(jlo:jhi)) lencounteri(box(jlo:jhi)) = .true. 
-            
-            return
-         end subroutine sweep_dl
    end subroutine encounter_check_sweep_aabb_all_double_list
 
 
@@ -1122,13 +1329,14 @@ subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, in
       ! Arguments
       integer(I4B),                         intent(in)    :: n          !! Number of bodies
       integer(I4B),         dimension(:),   intent(in)    :: ext_ind    !! Sorted index array of extents
-      integer(I4B),         dimension(:,:), intent(in)    :: ibeg, iend !! Beginning and ending index lists in the n-dimension
+      integer(I8B),         dimension(:,:), intent(in)    :: ibeg, iend !! Beginning and ending index lists in the n-dimension
       integer(I4B),         dimension(:),   intent(in)    :: ind_arr    !! index array for mapping body 2 indexes
       type(encounter_list), dimension(:),   intent(inout) :: lenc       !! Encounter list for the ith body   
       ! Internals
       integer(I4B) :: i
       logical, dimension(n) :: lencounteri, loverlap
-      integer(I4B), dimension(SWEEPDIM) :: ibegi, iendi
+      logical, dimension(:), allocatable :: lencounterj
+      integer(I8B), dimension(SWEEPDIM) :: ibegi, iendi
       integer(I4B), dimension(:), allocatable :: ext_ind_true
 
       allocate(ext_ind_true, mold=ext_ind)
@@ -1138,71 +1346,68 @@ subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, in
          ext_ind_true(:) = ext_ind(:)
       endwhere
 
-      loverlap(:) = (iend(1,:) + 1) > (ibeg(1,:) - 1)
+      loverlap(:) = (iend(1,:) + 1_I8B) > (ibeg(1,:) - 1_I8B)
       where(.not.loverlap(:)) lenc(:)%nenc = 0
+      lencounteri(:) = .false.
       !$omp parallel do default(private) schedule(static)&
       !$omp shared(ext_ind_true, ibeg, iend, ind_arr, lenc, loverlap) &
-      !$omp firstprivate(n) &
-      !$omp lastprivate(ibegi, iendi, lencounteri) 
+      !$omp firstprivate(n, lencounteri)
       do i = 1, n
          if (loverlap(i)) then
-            ibegi(1) = ibeg(1,i) + 1
-            iendi(1) = iend(1,i) - 1
+            ibegi(1) = ibeg(1,i) + 1_I8B
+            iendi(1) = iend(1,i) - 1_I8B
             ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
             iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            call sweep_sl(n, ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:))
-            call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), lenc(i)%nenc, lenc(i)%index2)
+            allocate(lencounterj(1 + iendi(1) - ibegi(1)))
+            lencounterj(:) = .true.
+            call sweep_list(ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:), lencounterj(:))
+            deallocate(lencounterj)
+            call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), i, lenc(i))
+            lencounteri(ext_ind_true(ibegi(1):iendi(1))) = .false.
          end if
       end do
       !$omp end parallel do
 
       return
-      
-      contains
+   end subroutine encounter_check_sweep_aabb_all_single_list
 
-         pure subroutine sweep_sl(n, ext_ind, ibegi, iendi, ibeg, iend, lencounteri)
-            !! author: David A. Minton
-            !!
-            !! Performs a sweep operation on a single body. Mutual encounters allowed (e.g. pl-pl)
-            implicit none
-            ! Arguments
-            integer(I4B),                 intent(in)  :: n            !! Number of bodies
-            integer(I4B), dimension(:),   intent(in)  :: ext_ind      !! Sorted index array of extents
-            integer(I4B), dimension(:),   intent(in)  :: ibegi, iendi !! The beginning and ending indices of the ith bounding box in the n-dimensions
-            integer(I4B), dimension(:,:), intent(in)  :: ibeg, iend   !! Beginning and ending index lists in the x-dimension
-            logical, dimension(:),        intent(out) :: lencounteri  !! Encounter list for the ith body
-            ! Internals
-            integer(I4B) :: j, jbox, dim, jlo, jhi
-            integer(I4B), dimension(ibegi(1):iendi(1)) :: box
-            logical, dimension(ibegi(1):iendi(1)) :: lencounterj
-            integer(I4B), dimension(ibegi(1):iendi(1)) :: iendy, ibegy
-            integer(I4B), dimension(ibegi(1):iendi(1)) :: iendz, ibegz
-
-            jlo = ibegi(1)
-            jhi = iendi(1)
-
-            lencounteri(:) = .false.
-            lencounterj(jlo:jhi) = .false.
-
-            box(jlo:jhi) = ext_ind(jlo:jhi)
-
-            ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))
-            iendy(jlo:jhi) = iend(2,box(jlo:jhi))
-            ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
-            iendz(jlo:jhi) = iend(3,box(jlo:jhi))
-
-            lencounterj(jlo:jhi) =       (iendy(jlo:jhi) > ibegi(2)) &
-                                   .and. (ibegy(jlo:jhi) < iendi(2)) &
-                                   .and. (iendz(jlo:jhi) > ibegi(3)) &
-                                   .and. (ibegz(jlo:jhi) < iendi(3)) 
-
-            do concurrent(jbox = jlo:jhi)
-               lencounteri(box(jbox)) = lencounterj(jbox)
-            end do
-
-            return
-         end subroutine sweep_sl
 
-   end subroutine encounter_check_sweep_aabb_all_single_list
+   pure subroutine sweep_list(ext_ind, ibegi, iendi, ibeg, iend, lencounteri, lencounterj)
+      !! author: David A. Minton
+      !!
+      !! Performs a sweep operation on a single body. Encounters from the same lists not allowed (e.g. pl-tp encounters only)
+      implicit none
+      ! Arguments
+      integer(I4B), dimension(:),   intent(in)    :: ext_ind      !! Sorted index array of extents
+      integer(I8B), dimension(:),   intent(in)    :: ibegi, iendi !! The beginning and ending indices of the ith bounding box in the n-dimensions
+      integer(I8B), dimension(:,:), intent(in)    :: ibeg, iend   !! Beginning and ending index lists in the n-dimensions
+      logical, dimension(:),        intent(out)   :: lencounteri    !! Encounter list for the ith body
+      logical, dimension(:),        intent(inout) :: lencounterj
+      ! Internals
+      integer(I8B) :: j, jbox, dim, jlo, jhi
+      integer(I4B), dimension(ibegi(1):iendi(1)) :: box
+      integer(I8B), dimension(ibegi(1):iendi(1)) :: iendy, ibegy
+      integer(I8B), dimension(ibegi(1):iendi(1)) :: iendz, ibegz
 
+      jlo = ibegi(1)
+      jhi = iendi(1)
+
+      box(jlo:jhi) = ext_ind(jlo:jhi)
+      
+      ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))
+      iendy(jlo:jhi) = iend(2,box(jlo:jhi))
+      ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
+      iendz(jlo:jhi) = iend(3,box(jlo:jhi))
+      
+      lencounterj(:) = lencounterj(:) .and. (iendy(jlo:jhi) > ibegi(2)) &
+                                      .and. (ibegy(jlo:jhi) < iendi(2)) &
+                                      .and. (iendz(jlo:jhi) > ibegi(3)) &
+                                      .and. (ibegz(jlo:jhi) < iendi(3))
+     
+      do concurrent (j = jlo:jhi, lencounterj(j - jlo + 1))
+         lencounteri(box(j)) = .true. 
+      end do
+      
+      return
+   end subroutine sweep_list
 end submodule s_encounter_check
diff --git a/src/encounter/encounter_setup.f90 b/src/encounter/encounter_setup.f90
index cb2e2f3d8..85439bd30 100644
--- a/src/encounter/encounter_setup.f90
+++ b/src/encounter/encounter_setup.f90
@@ -52,7 +52,7 @@ module subroutine encounter_setup_list(self, n)
       implicit none
       ! Arguments
       class(encounter_list), intent(inout) :: self !! Swiftest encounter structure
-      integer(I4B),              intent(in)    :: n    !! Number of encounters to allocate space for
+      integer(I8B),          intent(in)    :: n    !! Number of encounters to allocate space for
 
       if (n < 0) return
 
@@ -69,7 +69,7 @@ module subroutine encounter_setup_list(self, n)
       if (allocated(self%t)) deallocate(self%t)
 
       self%nenc = n
-      if (n == 0) return
+      if (n == 0_I8B) return
 
       allocate(self%lvdotr(n))
       allocate(self%status(n))
diff --git a/src/encounter/encounter_util.f90 b/src/encounter/encounter_util.f90
index c6dc03d7b..fb971f403 100644
--- a/src/encounter/encounter_util.f90
+++ b/src/encounter/encounter_util.f90
@@ -140,27 +140,27 @@ module subroutine encounter_util_resize_list(self, nnew)
       implicit none
       ! Arguments
       class(encounter_list), intent(inout) :: self !! Swiftest encounter list 
-      integer(I4B),              intent(in)    :: nnew !! New size of list needed
+      integer(I8B),              intent(in)    :: nnew !! New size of list needed
       ! Internals
       class(encounter_list), allocatable :: enc_temp
-      integer(I4B)                           :: nold
+      integer(I8B)                           :: nold
       logical                                :: lmalloc
 
       lmalloc = allocated(self%status)
       if (lmalloc) then
          nold = size(self%status)
       else
-         nold = 0
+         nold = 0_I8B
       end if
       if (nnew > nold) then
          if (lmalloc) allocate(enc_temp, source=self)
-         call self%setup(2 * nnew)
+         call self%setup(2_I8B * nnew)
          if (lmalloc) then
             call self%copy(enc_temp)
             deallocate(enc_temp)
          end if
       else
-         self%status(nnew+1:nold) = INACTIVE
+         self%status(nnew+1_I8B:nold) = INACTIVE
       end if
       self%nenc = nnew
 
@@ -179,7 +179,7 @@ module subroutine encounter_util_spill_list(self, discards, lspill_list, ldestru
       logical, dimension(:),     intent(in)    :: lspill_list  !! Logical array of bodies to spill into the discards
       logical,                   intent(in)    :: ldestructive !! Logical flag indicating whether or not this operation should alter body by removing the discard list
       ! Internals
-      integer(I4B) :: nenc_old
+      integer(I8B) :: nenc_old
   
       associate(keeps => self)
          call util_spill(keeps%lvdotr, discards%lvdotr, lspill_list, ldestructive)
diff --git a/src/modules/encounter_classes.f90 b/src/modules/encounter_classes.f90
index e9959316b..bf85eb626 100644
--- a/src/modules/encounter_classes.f90
+++ b/src/modules/encounter_classes.f90
@@ -10,7 +10,7 @@ module encounter_classes
    integer(I4B), parameter :: SWEEPDIM = 3
 
    type :: encounter_list
-      integer(I4B)                              :: nenc = 0  !! Total number of encounters
+      integer(I8B)                              :: nenc = 0  !! Total number of encounters
       logical,      dimension(:),   allocatable :: lvdotr !! relative vdotr flag
       integer(I4B), dimension(:),   allocatable :: status !! status of the interaction
       integer(I4B), dimension(:),   allocatable :: index1 !! position of the first body in the encounter
@@ -36,8 +36,8 @@ module encounter_classes
    type encounter_bounding_box_1D
       integer(I4B)                            :: n    !! Number of bodies with extents
       integer(I4B), dimension(:), allocatable :: ind  !! Sorted minimum/maximum extent indices (value > n indicates an ending index)
-      integer(I4B), dimension(:), allocatable :: ibeg !! Beginning index for box
-      integer(I4B), dimension(:), allocatable :: iend !! Ending index for box
+      integer(I8B), dimension(:), allocatable :: ibeg !! Beginning index for box
+      integer(I8B), dimension(:), allocatable :: iend !! Ending index for box
    contains
       procedure :: sort  => encounter_check_sort_aabb_1D !! Sorts the bounding box extents along a single dimension prior to the sweep phase
       procedure :: dealloc => encounter_util_dealloc_aabb !! Deallocates all allocatables
@@ -56,7 +56,7 @@ module encounter_classes
    interface
       module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc1, renc2, dt, lencounter, lvdotr)
          implicit none
-         integer(I4B),                 intent(in)  :: nenc         !! Number of encounters in the encounter lists
+         integer(I8B),                 intent(in)  :: nenc         !! Number of encounters in the encounter lists
          integer(I4B), dimension(:),   intent(in)  :: index1     !! List of indices for body 1 in each encounter
          integer(I4B), dimension(:),   intent(in)  :: index2     !! List of indices for body 2 in each encounter1
          real(DP),     dimension(:,:), intent(in)  :: x1, v1     !! Array of indices of bodies 1
@@ -80,7 +80,7 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, lvdotr, i
          logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
          integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
          integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-         integer(I4B),                            intent(out)   :: nenc   !! Total number of encounters
+         integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       end subroutine encounter_check_all_plpl
 
       module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, lvdotr, index1, index2, nenc)
@@ -99,7 +99,7 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
          integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
          integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-         integer(I4B),                            intent(out)   :: nenc   !! Total number of encounters
+         integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       end subroutine encounter_check_all_plplm
 
       module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc)
@@ -117,7 +117,7 @@ module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp,
          logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
          integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
          integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-         integer(I4B),                            intent(out)   :: nenc   !! Total number of encounters
+         integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       end subroutine encounter_check_all_pltp
 
       module pure subroutine encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc, dt, lencounter, lvdotr)
@@ -135,7 +135,7 @@ module subroutine encounter_check_collapse_ragged_list(ragged_list, n1, nenc, in
          implicit none
          type(encounter_list), dimension(:),              intent(in)            :: ragged_list !! The ragged encounter list
          integer(I4B),                                    intent(in)            :: n1          !! Number of bodies 1
-         integer(I4B),                                    intent(out)           :: nenc        !! Total number of encountersj 
+         integer(I8B),                                    intent(out)           :: nenc        !! Total number of encountersj 
          integer(I4B),         dimension(:), allocatable, intent(out)           :: index1      !! Array of indices for body 1
          integer(I4B),         dimension(:), allocatable, intent(out)           :: index2      !! Array of indices for body 1
          logical,              dimension(:), allocatable, intent(out), optional :: lvdotr      !! Array indicating which bodies are approaching
@@ -153,7 +153,7 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, ind
          class(encounter_bounding_box),           intent(inout) :: self     !! Multi-dimensional bounding box structure
          integer(I4B),                            intent(in)    :: n1       !! Number of bodies 1
          integer(I4B),                            intent(in)    :: n2       !! Number of bodies 2
-         integer(I4B),                            intent(out)   :: nenc     !! Total number of encounter candidates
+         integer(I8B),                            intent(out)   :: nenc     !! Total number of encounter candidates
          integer(I4B), dimension(:), allocatable, intent(out)   :: index1   !! List of indices for body 1 in each encounter candidate pair
          integer(I4B), dimension(:), allocatable, intent(out)   :: index2   !! List of indices for body 2 in each encounter candidate pair
       end subroutine encounter_check_sweep_aabb_double_list
@@ -162,7 +162,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, nenc, index1,
          implicit none
          class(encounter_bounding_box),           intent(inout) :: self    !! Multi-dimensional bounding box structure
          integer(I4B),                            intent(in)    :: n       !! Number of bodies 1
-         integer(I4B),                            intent(out)   :: nenc    !! Total number of encounter candidates
+         integer(I8B),                            intent(out)   :: nenc    !! Total number of encounter candidates
          integer(I4B), dimension(:), allocatable, intent(out)   :: index1  !! List of indices for body 1 in each encounter candidate pair
          integer(I4B), dimension(:), allocatable, intent(out)   :: index2  !! List of indices for body 2 in each encounter candidate pair
       end subroutine encounter_check_sweep_aabb_single_list
@@ -181,7 +181,7 @@ end subroutine encounter_io_write_frame
       module subroutine encounter_io_write_list(self, pl, encbody, param)
          use swiftest_classes, only : swiftest_pl, swiftest_body, swiftest_parameters
          implicit none
-         class(encounter_list),  intent(in) :: self    !! Swiftest encounter list object
+         class(encounter_list),      intent(in) :: self    !! Swiftest encounter list object
          class(swiftest_pl),         intent(in) :: pl      !! Swiftest massive body object
          class(swiftest_body),       intent(in) :: encbody !! Encountering body - Swiftest generic body object (pl or tp) 
          class(swiftest_parameters), intent(in) :: param   !! Current run configuration parameters 
@@ -197,14 +197,14 @@ end subroutine encounter_setup_aabb
       module subroutine encounter_setup_list(self, n)
          implicit none
          class(encounter_list), intent(inout) :: self !! Swiftest encounter structure
-         integer(I4B),              intent(in)    :: n    !! Number of encounters to allocate space for
+         integer(I8B),          intent(in)    :: n    !! Number of encounters to allocate space for
       end subroutine encounter_setup_list
 
       module subroutine encounter_util_append_list(self, source, lsource_mask)
          implicit none
          class(encounter_list), intent(inout) :: self         !! Swiftest encounter list object
          class(encounter_list), intent(in)    :: source       !! Source object to append
-         logical, dimension(:),     intent(in)    :: lsource_mask !! Logical mask indicating which elements to append to
+         logical, dimension(:), intent(in)    :: lsource_mask !! Logical mask indicating which elements to append to
       end subroutine encounter_util_append_list
 
       module subroutine encounter_util_copy_list(self, source)
@@ -236,15 +236,15 @@ end subroutine encounter_util_final_list
       module subroutine encounter_util_resize_list(self, nnew)
          implicit none
          class(encounter_list), intent(inout) :: self !! Swiftest encounter list 
-         integer(I4B),         intent(in)    :: nnew !! New size of list needed
+         integer(I8B),          intent(in)    :: nnew !! New size of list needed
       end subroutine encounter_util_resize_list
 
       module subroutine encounter_util_spill_list(self, discards, lspill_list, ldestructive)
          implicit none
          class(encounter_list), intent(inout) :: self         !! Swiftest encounter list 
          class(encounter_list), intent(inout) :: discards     !! Discarded object 
-         logical, dimension(:),     intent(in)    :: lspill_list  !! Logical array of bodies to spill into the discards
-         logical,                   intent(in)    :: ldestructive !! Logical flag indicating whether or not this operation should alter body by removing the discard list
+         logical, dimension(:), intent(in)    :: lspill_list  !! Logical array of bodies to spill into the discards
+         logical,               intent(in)    :: ldestructive !! Logical flag indicating whether or not this operation should alter body by removing the discard list
       end subroutine encounter_util_spill_list
 
    end interface
diff --git a/src/modules/swiftest_classes.f90 b/src/modules/swiftest_classes.f90
index eeabc092b..f93fcf517 100644
--- a/src/modules/swiftest_classes.f90
+++ b/src/modules/swiftest_classes.f90
@@ -1661,6 +1661,12 @@ module pure subroutine util_sort_index_i4b(arr,ind)
          integer(I4B), dimension(:), allocatable, intent(inout) :: ind
       end subroutine util_sort_index_i4b
 
+      module pure subroutine util_sort_index_i4b_I8Bind(arr,ind)
+         implicit none
+         integer(I4B), dimension(:), intent(in)  :: arr
+         integer(I8B), dimension(:), allocatable, intent(inout) :: ind
+      end subroutine util_sort_index_i4b_I8Bind
+
       module pure subroutine util_sort_sp(arr)
          implicit none
          real(SP), dimension(:), intent(inout) :: arr
@@ -1713,6 +1719,13 @@ module pure subroutine util_sort_rearrange_arr_I4B(arr, ind, n)
          integer(I4B),                             intent(in)    :: n   !! Number of elements in arr and ind to rearrange
       end subroutine util_sort_rearrange_arr_I4B
 
+      module pure subroutine util_sort_rearrange_arr_I4B_I8Bind(arr, ind, n)
+         implicit none
+         integer(I4B), dimension(:), allocatable, intent(inout) :: arr !! Destination array 
+         integer(I8B), dimension(:),              intent(in)    :: ind !! Index to rearrange against
+         integer(I8B),                             intent(in)    :: n   !! Number of elements in arr and ind to rearrange
+      end subroutine util_sort_rearrange_arr_I4B_I8Bind
+
       module subroutine util_sort_rearrange_arr_info(arr, ind, n)
          implicit none
          type(swiftest_particle_info), dimension(:), allocatable, intent(inout) :: arr !! Destination array 
@@ -1726,6 +1739,13 @@ module pure subroutine util_sort_rearrange_arr_logical(arr, ind, n)
          integer(I4B), dimension(:),              intent(in)    :: ind !! Index to rearrange against
          integer(I4B),                            intent(in)    :: n   !! Number of elements in arr and ind to rearrange
       end subroutine util_sort_rearrange_arr_logical
+
+      module pure subroutine util_sort_rearrange_arr_logical_I8Bind(arr, ind, n)
+         implicit none
+         logical,      dimension(:), allocatable, intent(inout) :: arr !! Destination array 
+         integer(I8B), dimension(:),              intent(in)    :: ind !! Index to rearrange against
+         integer(I8B),                            intent(in)    :: n   !! Number of elements in arr and ind to rearrange
+      end subroutine util_sort_rearrange_arr_logical_I8Bind
    end interface util_sort_rearrange
 
    interface
diff --git a/src/modules/symba_classes.f90 b/src/modules/symba_classes.f90
index 4a584eda9..2ac47be8d 100644
--- a/src/modules/symba_classes.f90
+++ b/src/modules/symba_classes.f90
@@ -427,7 +427,7 @@ end subroutine symba_setup_pl
       module subroutine symba_setup_encounter_list(self,n)
          implicit none
          class(symba_encounter), intent(inout) :: self !! SyMBA pl-tp encounter structure
-         integer(I4B),           intent(in)    :: n    !! Number of encounters to allocate space for
+         integer(I8B),           intent(in)    :: n    !! Number of encounters to allocate space for
       end subroutine symba_setup_encounter_list
 
       module subroutine symba_setup_tp(self, n, param)
diff --git a/src/rmvs/rmvs_encounter_check.f90 b/src/rmvs/rmvs_encounter_check.f90
index 68fe7a2ef..c63e7f2de 100644
--- a/src/rmvs/rmvs_encounter_check.f90
+++ b/src/rmvs/rmvs_encounter_check.f90
@@ -18,7 +18,8 @@ module function rmvs_encounter_check_tp(self, param, system, dt) result(lencount
       ! Result
       logical                                 :: lencounter  !! Returns true if there is at least one close encounter
       ! Internals
-      integer(I4B)                            :: i, j, nenc
+      integer(I4B)                            :: i, j
+      integer(I8B)                            :: nenc
       real(DP)                                :: xr, yr, zr, vxr, vyr, vzr
       real(DP), dimension(system%pl%nbody)    :: rcrit
       logical                                 :: lflag
@@ -37,9 +38,9 @@ module function rmvs_encounter_check_tp(self, param, system, dt) result(lencount
             tp%plencP(1:ntp) = 0
             call encounter_check_all_pltp(param, npl, ntp, pl%xbeg, pl%vbeg, tp%xh, tp%vh, pl%renc, dt, lvdotr, index1, index2, nenc)
 
-            lencounter = (nenc > 0)
+            lencounter = (nenc > 0_I8B)
             if (lencounter) then
-               tp%plencP(index2(1:nenc)) = index1(1:nenc)
+               tp%plencP(index2(1_I8B:nenc)) = index1(1_I8B:nenc)
                do j = 1, npl
                   pl%nenc(j) = count(tp%plencP(1:ntp) == j)
                end do
diff --git a/src/symba/symba_encounter_check.f90 b/src/symba/symba_encounter_check.f90
index f75fc49f2..241657b67 100644
--- a/src/symba/symba_encounter_check.f90
+++ b/src/symba/symba_encounter_check.f90
@@ -17,8 +17,8 @@ module function symba_encounter_check_pl(self, param, system, dt, irec) result(l
       ! Result
       logical                                   :: lany_encounter !! Returns true if there is at least one close encounter      
       ! Internals
-      integer(I8B) :: k, nplplm, kenc
-      integer(I4B) :: i, j, nenc, npl, nplm, nplt
+      integer(I8B) :: k, nplplm, kenc, nenc
+      integer(I4B) :: i, j, npl, nplm, nplt
       logical, dimension(:), allocatable :: lencounter, loc_lvdotr, lvdotr
       integer(I4B), dimension(:), allocatable :: index1, index2
       integer(I4B), dimension(:,:), allocatable :: k_plpl_enc 
@@ -43,7 +43,7 @@ module function symba_encounter_check_pl(self, param, system, dt, irec) result(l
             call encounter_check_all_plplm(param, nplm, nplt, pl%xh(:,1:nplm), pl%vh(:,1:nplm), pl%xh(:,nplm+1:npl), pl%vh(:,nplm+1:npl), pl%renc(1:nplm), pl%renc(nplm+1:npl), dt, lvdotr, index1, index2, nenc)
          end if
          
-         lany_encounter = nenc > 0
+         lany_encounter = nenc > 0_I8B
          if (lany_encounter) then
             call plplenc_list%resize(nenc)
             call move_alloc(lvdotr, plplenc_list%lvdotr)
@@ -52,7 +52,7 @@ module function symba_encounter_check_pl(self, param, system, dt, irec) result(l
          end if
 
          if (lany_encounter) then 
-            do k = 1, nenc
+            do k = 1_I8B, nenc
                i = plplenc_list%index1(k)
                j = plplenc_list%index2(k)
                plplenc_list%id1(k) = pl%id(i)
@@ -197,7 +197,8 @@ module function symba_encounter_check_tp(self, param, system, dt, irec) result(l
       logical                                   :: lany_encounter !! Returns true if there is at least one close encounter      
       ! Internals
       real(DP)                                  :: r2crit, vdotr, r2, v2, tmin, r2min, term2
-      integer(I4B)                              :: i, j, k,nenc, plind, tpind
+      integer(I4B)                              :: i, j, plind, tpind
+      integer(I8B)                              :: k, nenc
       real(DP),     dimension(NDIM)             :: xr, vr
       real(DP)                                  :: rshell_irec
       logical,      dimension(:),   allocatable :: lvdotr
@@ -224,7 +225,7 @@ module function symba_encounter_check_tp(self, param, system, dt, irec) result(l
                select type(pl)
                class is (symba_pl)
                   pl%lencounter(1:npl) = .false.
-                  do k = 1, nenc
+                  do k = 1_I8B, nenc
                      plind = pltpenc_list%index1(k)
                      tpind = pltpenc_list%index2(k)
                      pl%lencounter(plind) = .true.
diff --git a/src/symba/symba_setup.f90 b/src/symba/symba_setup.f90
index bb300f63d..cecb4d806 100644
--- a/src/symba/symba_setup.f90
+++ b/src/symba/symba_setup.f90
@@ -109,14 +109,14 @@ module subroutine symba_setup_encounter_list(self, n)
       implicit none
       ! Arguments
       class(symba_encounter), intent(inout) :: self !! SyMBA pl-tp encounter structure
-      integer(I4B),         intent(in)    :: n    !! Number of encounters to allocate space for
+      integer(I8B),           intent(in)    :: n    !! Number of encounters to allocate space for
 
       call encounter_setup_list(self, n)
-      if (n < 0) return
+      if (n < 0_I8B) return
 
       call self%dealloc()
 
-      if (n ==0) return
+      if (n ==0_I8B) return
 
       allocate(self%level(n))
 
diff --git a/src/symba/symba_step.f90 b/src/symba/symba_step.f90
index eac112dcd..7bd2ff562 100644
--- a/src/symba/symba_step.f90
+++ b/src/symba/symba_step.f90
@@ -226,7 +226,8 @@ module subroutine symba_step_reset_system(self, param)
       class(symba_nbody_system), intent(inout) :: self  !! SyMBA nbody system object
       class(symba_parameters),   intent(in)    :: param !! Current run configuration parameters with SyMBA additions
       ! Internals
-      integer(I4B) :: i, nenc_old
+      integer(I4B) :: i
+      integer(I8B) :: nenc_old
 
       associate(system => self)
          select type(pl => system%pl)
diff --git a/src/symba/symba_util.f90 b/src/symba/symba_util.f90
index fcb576d0f..892008aea 100644
--- a/src/symba/symba_util.f90
+++ b/src/symba/symba_util.f90
@@ -38,17 +38,19 @@ module subroutine symba_util_append_encounter_list(self, source, lsource_mask)
       !! This method will automatically resize the destination body if it is too small
       implicit none
       ! Arguments
-      class(symba_encounter),    intent(inout) :: self         !! SyMBA encounter list object
-      class(encounter_list), intent(in)    :: source       !! Source object to append
-      logical, dimension(:),     intent(in)    :: lsource_mask !! Logical mask indicating which elements to append to
+      class(symba_encounter), intent(inout) :: self         !! SyMBA encounter list object
+      class(encounter_list),  intent(in)    :: source       !! Source object to append
+      logical, dimension(:),  intent(in)    :: lsource_mask !! Logical mask indicating which elements to append to
+      ! Internals
+      integer(I4B) :: nold, nsrc
 
-      associate(nold => self%nenc, nsrc => source%nenc)
-         select type(source)
-         class is (symba_encounter)
-            call util_append(self%level, source%level, nold, nsrc, lsource_mask)
-         end select
-         call encounter_util_append_list(self, source, lsource_mask) 
-      end associate
+      nold = self%nenc
+      nsrc = source%nenc
+      select type(source)
+      class is (symba_encounter)
+         call util_append(self%level, source%level, nold, nsrc, lsource_mask)
+      end select
+      call encounter_util_append_list(self, source, lsource_mask) 
 
       return
    end subroutine symba_util_append_encounter_list
diff --git a/src/util/util_sort.f90 b/src/util/util_sort.f90
index 84371b773..e0dfad022 100644
--- a/src/util/util_sort.f90
+++ b/src/util/util_sort.f90
@@ -202,7 +202,7 @@ module pure subroutine util_sort_i4b(arr)
    end subroutine util_sort_i4b
 
 
-   module pure subroutine util_sort_index_i4b(arr, ind)
+   module pure subroutine util_sort_index_I4B(arr, ind)
       !! author: David A. Minton
       !!
       !! Sort input integer array by index in ascending numerical order using quicksort.
@@ -227,20 +227,48 @@ module pure subroutine util_sort_index_i4b(arr, ind)
       call qsort_I4B(tmparr, ind)
 
       return
-   end subroutine util_sort_index_i4b
+   end subroutine util_sort_index_I4B
+
+
+   module pure subroutine util_sort_index_I4B_I8Bind(arr, ind)
+      !! author: David A. Minton
+      !!
+      !! Sort input integer array by index in ascending numerical order using quicksort.
+      !! If ind is supplied already allocated, we assume it is an existing index array (e.g. a previously
+      !! sorted array). If it is not allocated, this subroutine allocates it.
+      !!
+      implicit none
+      ! Arguments
+      integer(I4B), dimension(:),              intent(in)  :: arr
+      integer(I8B), dimension(:), allocatable, intent(inout) :: ind
+      ! Internals
+      integer(I8B) :: n, i
+      integer(I4B), dimension(:), allocatable :: tmparr
+
+      n = size(arr)
+      if (.not.allocated(ind)) then
+         allocate(ind(n))
+         ind = [(i, i=1_I8B, n)]
+      end if
+      allocate(tmparr, mold=arr)
+      tmparr(:) = arr(ind(:))
+      call qsort_I4B_I8Bind(tmparr, ind)
+
+      return
+   end subroutine util_sort_index_I4B_I8Bind
 
 
    recursive pure subroutine qsort_I4B(arr, ind)
       !! author: David A. Minton
       !!
-      !! Sort input DP precision array by index in ascending numerical order using quicksort.
+      !! Sort input I4B array by index in ascending numerical order using quicksort.
       !!
       implicit none
       ! Arguments
       integer(I4B), dimension(:), intent(inout)          :: arr
       integer(I4B), dimension(:), intent(out),  optional :: ind
-      !! Internals
-      integer :: iq
+      ! Internals
+      integer(I4B) :: iq
 
       if (size(arr) > 1) then
          if (present(ind)) then
@@ -257,6 +285,33 @@ recursive pure subroutine qsort_I4B(arr, ind)
       return
    end subroutine qsort_I4B
 
+   recursive pure subroutine qsort_I4B_I8Bind(arr, ind)
+      !! author: David A. Minton
+      !!
+      !! Sort input I4B array by index in ascending numerical order using quicksort.
+      !!
+      implicit none
+      ! Arguments
+      integer(I4B), dimension(:), intent(inout)          :: arr
+      integer(I8B), dimension(:), intent(out),  optional :: ind
+      ! Internals
+      integer(I8B) :: iq
+
+      if (size(arr) > 1_I8B) then
+         if (present(ind)) then
+            call partition_I4B_I8Bind(arr, iq, ind)
+            call qsort_I4B_I8Bind(arr(:iq-1_I8B),ind(:iq-1_I8B))
+            call qsort_I4B_I8Bind(arr(iq:),  ind(iq:))
+         else
+            call partition_I4B_I8Bind(arr, iq)
+            call qsort_I4B_I8Bind(arr(:iq-1_I8B))
+            call qsort_I4B_I8Bind(arr(iq:))
+         end if
+      end if
+
+      return
+   end subroutine qsort_I4B_I8Bind
+
  
    pure subroutine partition_I4B(arr, marker, ind)
       !! author: David A. Minton
@@ -314,6 +369,62 @@ pure subroutine partition_I4B(arr, marker, ind)
       return
    end subroutine partition_I4B
 
+   pure subroutine partition_I4B_I8Bind(arr, marker, ind)
+      !! author: David A. Minton
+      !!
+      !! Partition function for quicksort on I4B type
+      !!
+      implicit none
+      ! Arguments
+      integer(I4B), intent(inout), dimension(:)           :: arr
+      integer(I8B), intent(inout), dimension(:), optional :: ind
+      integer(I8B), intent(out)                           :: marker
+      ! Internals
+      integer(I8B) :: i, j, itmp, narr, ipiv
+      integer(I4B) :: temp
+      integer(I8B) :: x   ! pivot point
+
+      narr = size(arr)
+
+      ! Get center as pivot, as this is likely partially sorted
+      ipiv = narr / 2_I8B
+      x = arr(ipiv)
+      i = 0_I8B
+      j = narr + 1_I8B
+   
+      do
+         j = j - 1_I8B
+         do
+            if (arr(j) <= x) exit
+            j = j - 1_I8B
+         end do
+         i = i + 1_I8B
+         do
+            if (arr(i) >= x) exit
+            i = i + 1_I8B
+         end do
+         if (i < j) then
+            ! exchange A(i) and A(j)
+            temp = arr(i)
+            arr(i) = arr(j)
+            arr(j) = temp
+            if (present(ind)) then
+               itmp = ind(i)
+               ind(i) = ind(j)
+               ind(j) = itmp
+            end if
+         else if (i == j) then
+            marker = i + 1_I8B
+            return
+         else
+            marker = i
+            return
+         endif
+      end do
+  
+      return
+   end subroutine partition_I4B_I8Bind
+
 
    module pure subroutine util_sort_sp(arr)
       !! author: David A. Minton
@@ -662,6 +773,26 @@ module pure subroutine util_sort_rearrange_arr_I4B(arr, ind, n)
       return
    end subroutine util_sort_rearrange_arr_I4B
 
+   module pure subroutine util_sort_rearrange_arr_I4B_I8Bind(arr, ind, n)
+      !! author: David A. Minton
+      !!
+      !! Rearrange a single array of integers in-place from an index list.
+      implicit none
+      ! Arguments
+      integer(I4B), dimension(:), allocatable, intent(inout) :: arr !! Destination array 
+      integer(I8B), dimension(:),              intent(in)    :: ind !! Index to rearrange against
+      integer(I8B),                            intent(in)    :: n   !! Number of elements in arr and ind to rearrange
+      ! Internals
+      integer(I4B), dimension(:), allocatable                :: tmp !! Temporary copy of array used during rearrange operation
+
+      if (.not. allocated(arr) .or. n <= 0_I8B) return
+      allocate(tmp, mold=arr)
+      tmp(1:n) = arr(ind)
+      call move_alloc(tmp, arr)
+
+      return
+   end subroutine util_sort_rearrange_arr_I4B_I8Bind
+
 
    module pure subroutine util_sort_rearrange_arr_logical(arr, ind, n)
       !! author: David A. Minton
@@ -684,6 +815,27 @@ module pure subroutine util_sort_rearrange_arr_logical(arr, ind, n)
    end subroutine util_sort_rearrange_arr_logical
 
 
+   module pure subroutine util_sort_rearrange_arr_logical_I8Bind(arr, ind, n)
+      !! author: David A. Minton
+      !!
+      !! Rearrange a single array of logicals in-place from an index list.
+      implicit none
+      ! Arguments
+      logical,      dimension(:), allocatable, intent(inout) :: arr !! Destination array 
+      integer(I8B), dimension(:),              intent(in)    :: ind !! Index to rearrange against
+      integer(I8B),                            intent(in)    :: n   !! Number of elements in arr and ind to rearrange
+      ! Internals
+      logical, dimension(:), allocatable                :: tmp !! Temporary copy of array used during rearrange operation
+
+      if (.not. allocated(arr) .or. n <= 0) return
+      allocate(tmp, mold=arr)
+      tmp(1:n) = arr(ind)
+      call move_alloc(tmp, arr)
+
+      return
+   end subroutine util_sort_rearrange_arr_logical_I8Bind
+
+
    module subroutine util_sort_rearrange_arr_info(arr, ind, n)
       !! author: David A. Minton
       !!

From f9ba3a85671866d35dd9ea2da708eef38299b34f Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Mon, 22 Nov 2021 17:00:26 -0500
Subject: [PATCH 12/24] More performance enhancements to the double list
 encounter sweep check

---
 src/encounter/encounter_check.f90 | 92 +++++++++++++------------------
 1 file changed, 39 insertions(+), 53 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index ac6d71d38..1c4f26360 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -570,7 +570,7 @@ subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1,
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I8B) :: ibegix, iendix
       integer(I8B), pointer :: ibegx, ibegy
-      integer(I4B), dimension(:), allocatable :: index1i, index2i, itmp
+      integer(I4B), dimension(:), allocatable :: index1i, index2i, itmp, box
       type(walltimer) :: timer1, timer2, timer3, timer4, timer5
       logical, save :: lfirst = .true.
 
@@ -603,7 +603,7 @@ subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1,
          
          call timer1%start()
          !$omp parallel do default(private) schedule(static)&
-         !$omp shared(ext_ind_true, ibegx, iendx, ind_arr, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
+         !$omp shared(ext_ind_true, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
          !$omp firstprivate(ntot, n1, dt) 
          do i = 1, ntot
             if (loverlap(i)) then
@@ -611,64 +611,51 @@ subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1,
                iendix = iendx(i) - 1_I8B
                call timer2%start()
                if (i <= n1) then
-                  lenc(i)%nenc = count(.not.llist1(ibegix:iendix))
+                  nbox = count(.not.llist1(ibegix:iendix))
                else
-                  lenc(i)%nenc = count(llist1(ibegix:iendix))
+                  nbox = count(llist1(ibegix:iendix))
                end if
                call timer2%stop()
-               if (lenc(i)%nenc > 0_I8B) then
+               if (nbox > 0_I8B) then
                   ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
-                  call timer3%start()
-                  nbox = iendix - ibegix + 1_I8B
-                  if (allocated(lenctrue)) deallocate(lenctrue); allocate(lenctrue(nbox))
-                  if (allocated(lvdotri)) deallocate(lvdotri); allocate(lvdotri(nbox))
+
+                  if (allocated(box)) deallocate(box); allocate(box(nbox))
                   if (allocated(index1i)) deallocate(index1i); allocate(index1i(nbox))
                   if (allocated(index2i)) deallocate(index2i); allocate(index2i(nbox))
-                  lenctrue(:) = .false.
-                  lvdotri(:) = .false.
-                  call timer3%stop()
 
-                  call timer4%start()
                   if (i <= n1) then
-                     do concurrent(k=ibegix:iendix, .not.llist1(k))
-                        kk = k - ibegix + 1_I8B
-                        ii = i
-                        jj = ext_ind_true(k) - n1
-                        index1i(kk) = ii
-                        index2i(kk) = jj
-                     end do
-                     do concurrent(kk=1:nbox, .not.llist1(kk+ibegix-1_I8B))
-                        ii = index1i(kk)
-                        jj = index2i(kk)
-                        call encounter_check_sweep_check_one(x1(1,ii), x1(2,ii), x1(3,ii), &
-                                                             x2(1,jj), x2(2,jj), x2(3,jj), &  
-                                                             v1(1,ii), v1(2,ii), v1(3,ii), &  
-                                                             v2(1,jj), v2(2,jj), v2(3,jj), &  
-                                                             renc1(ii), renc2(jj), dt, &
-                                                             lenctrue(kk), lvdotri(kk))
-                     end do
+                     call timer3%start()
+                     box(:) = pack(ext_ind_true(ibegix:iendix), .not.llist1(ibegix:iendix))
+                     call timer3%stop()
+                     call timer4%start()
+                     index1i(:) = i
+                     index2i(:) = box(:) - n1
+                     call timer4%stop()
                   else
-                     do concurrent(k=ibegix:iendix, llist1(k))
-                        kk = k - ibegix + 1_I8B
-                        ii = ext_ind_true(k)
-                        jj = i - n1
-                        index1i(kk) = ii
-                        index2i(kk) = jj
-                     end do
-                     do concurrent(kk=1:nbox, llist1(kk+ibegix-1_I8B))
-                        ii = index1i(kk)
-                        jj = index2i(kk)
-                        call encounter_check_sweep_check_one(x1(1,ii), x1(2,ii), x1(3,ii), &
-                                                             x2(1,jj), x2(2,jj), x2(3,jj), &  
-                                                             v1(1,ii), v1(2,ii), v1(3,ii), &  
-                                                             v2(1,jj), v2(2,jj), v2(3,jj), &  
-                                                             renc1(ii), renc2(jj), dt, &
-                                                             lenctrue(kk), lvdotri(kk))
-                     end do
+                     call timer3%start()
+                     box(:) = pack(ext_ind_true(ibegix:iendix), llist1(ibegix:iendix))
+                     call timer3%stop()
+                     call timer4%start()
+                     index1i(:) = box(:)
+                     index2i(:) = i - n1
+                     call timer4%stop()
                   end if
-                  call timer4%stop()
 
                   call timer5%start()
+                  if (allocated(lenctrue)) deallocate(lenctrue); allocate(lenctrue(nbox))
+                  if (allocated(lvdotri)) deallocate(lvdotri); allocate(lvdotri(nbox))
+                  do k=1,nbox
+                     ii = index1i(k)
+                     jj = index2i(k)
+                     call encounter_check_sweep_check_one(x1(1,ii), x1(2,ii), x1(3,ii), &
+                                                          x2(1,jj), x2(2,jj), x2(3,jj), &  
+                                                          v1(1,ii), v1(2,ii), v1(3,ii), &  
+                                                          v2(1,jj), v2(2,jj), v2(3,jj), &  
+                                                          renc1(ii), renc2(jj), dt, &
+                                                          lenctrue(k), lvdotri(k))
+                  end do
+                  call timer5%stop()
+
                   lenc(i)%nenc = count(lenctrue(:))
                   if (lenc(i)%nenc > 0_I8B) then
                      allocate(itmp(lenc(i)%nenc))
@@ -683,7 +670,6 @@ subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1,
                      ltmp = pack(lvdotri(:), lenctrue(:))
                      call move_alloc(ltmp, lenc(i)%lvdotr)
                   end if
-                  call timer5%stop()
                end if
             end if
          end do
@@ -691,10 +677,10 @@ subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1,
 
          call timer1%stop()
          call timer1%report(nsubsteps=1, message="timer1           :")
-         call timer2%report(nsubsteps=1, message="timer2           :")
-         call timer3%report(nsubsteps=1, message="timer3           :")
-         call timer4%report(nsubsteps=1, message="timer4           :")
-         call timer5%report(nsubsteps=1, message="timer5           :")
+         !call timer2%report(nsubsteps=1, message="timer2           :")
+         !call timer3%report(nsubsteps=1, message="timer3           :")
+         !call timer4%report(nsubsteps=1, message="timer4           :")
+         !call timer5%report(nsubsteps=1, message="timer5           :")
 
       end associate
 

From 20d57a4a602ab0981a16e8f9429fd1561eadc008 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Tue, 23 Nov 2021 09:49:03 -0500
Subject: [PATCH 13/24] Greatly stremalined the double list encounter checker

---
 src/encounter/encounter_check.f90 | 176 ++++++++++++++----------------
 1 file changed, 80 insertions(+), 96 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 1c4f26360..ce3871bd0 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -561,8 +561,10 @@ subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1,
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
       integer(I4B) :: ii, i, j, jj, ntot, dim
-      integer(I8B) :: k, kk, nbox
-      logical, dimension(n1+n2) :: lencounteri, loverlap
+      integer(I8B) :: k, kk
+      logical, dimension(n1+n2) :: loverlap
+      logical, dimension(n1) :: lencounter1
+      logical, dimension(n2) :: lencounter2
       logical, dimension(:), allocatable  :: lencounter, lvdotri
       logical, dimension(:), allocatable :: lencounterj, lenctrue, ltmp, llist1
       integer(I4B), dimension(:), allocatable :: ext_ind_true
@@ -600,88 +602,50 @@ subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1,
 
          loverlap(:) = (iendx(:) + 1) > (ibegx(:) - 1)
          where(.not.loverlap(:)) lenc(:)%nenc = 0
-         
-         call timer1%start()
+
+         ! call timer1%start()
          !$omp parallel do default(private) schedule(static)&
-         !$omp shared(ext_ind_true, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
-         !$omp firstprivate(ntot, n1, dt) 
-         do i = 1, ntot
+         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
+         !$omp firstprivate(ntot, n1, n2, dt) 
+         do i = 1, n1
             if (loverlap(i)) then
                ibegix = ibegx(i) + 1_I8B
                iendix = iendx(i) - 1_I8B
-               call timer2%start()
-               if (i <= n1) then
-                  nbox = count(.not.llist1(ibegix:iendix))
-               else
-                  nbox = count(llist1(ibegix:iendix))
-               end if
-               call timer2%stop()
-               if (nbox > 0_I8B) then
-                  ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
-
-                  if (allocated(box)) deallocate(box); allocate(box(nbox))
-                  if (allocated(index1i)) deallocate(index1i); allocate(index1i(nbox))
-                  if (allocated(index2i)) deallocate(index2i); allocate(index2i(nbox))
-
-                  if (i <= n1) then
-                     call timer3%start()
-                     box(:) = pack(ext_ind_true(ibegix:iendix), .not.llist1(ibegix:iendix))
-                     call timer3%stop()
-                     call timer4%start()
-                     index1i(:) = i
-                     index2i(:) = box(:) - n1
-                     call timer4%stop()
-                  else
-                     call timer3%start()
-                     box(:) = pack(ext_ind_true(ibegix:iendix), llist1(ibegix:iendix))
-                     call timer3%stop()
-                     call timer4%start()
-                     index1i(:) = box(:)
-                     index2i(:) = i - n1
-                     call timer4%stop()
-                  end if
-
-                  call timer5%start()
-                  if (allocated(lenctrue)) deallocate(lenctrue); allocate(lenctrue(nbox))
-                  if (allocated(lvdotri)) deallocate(lvdotri); allocate(lvdotri(nbox))
-                  do k=1,nbox
-                     ii = index1i(k)
-                     jj = index2i(k)
-                     call encounter_check_sweep_check_one(x1(1,ii), x1(2,ii), x1(3,ii), &
-                                                          x2(1,jj), x2(2,jj), x2(3,jj), &  
-                                                          v1(1,ii), v1(2,ii), v1(3,ii), &  
-                                                          v2(1,jj), v2(2,jj), v2(3,jj), &  
-                                                          renc1(ii), renc2(jj), dt, &
-                                                          lenctrue(k), lvdotri(k))
-                  end do
-                  call timer5%stop()
-
-                  lenc(i)%nenc = count(lenctrue(:))
-                  if (lenc(i)%nenc > 0_I8B) then
-                     allocate(itmp(lenc(i)%nenc))
-                     itmp = pack(index1i(:), lenctrue(:))
-                     call move_alloc(itmp, lenc(i)%index1)
-
-                     allocate(itmp(lenc(i)%nenc))
-                     itmp = pack(index2i(:), lenctrue(:))
-                     call move_alloc(itmp, lenc(i)%index2)
-
-                     allocate(ltmp(lenc(i)%nenc))
-                     ltmp = pack(lvdotri(:), lenctrue(:))
-                     call move_alloc(ltmp, lenc(i)%lvdotr)
-                  end if
-               end if
-            end if
+
+               lencounter2(:) = .false.
+               where(.not.llist1(ibegix:iendix)) lencounter2(ext_ind_true(ibegix:iendix) - n1) = .true.
+               call encounter_check_sweep_check_all_one(i, n2, x1(1,i), x1(2,i), x1(3,i), v1(1,i), v1(2,i), v1(3,i), &
+                                                               x2(1,:), x2(2,:), x2(3,:), v2(1,:), v2(2,:), v2(3,:), &
+                                                               renc1(i), renc2(:), dt, ind_arr, lencounter2(:), &
+                                                               lenc(i)%nenc, lenc(i)%lvdotr, lenc(i)%index1, lenc(i)%index2)
+             end if
          end do
          !$omp end parallel do
 
-         call timer1%stop()
-         call timer1%report(nsubsteps=1, message="timer1           :")
-         !call timer2%report(nsubsteps=1, message="timer2           :")
-         !call timer3%report(nsubsteps=1, message="timer3           :")
-         !call timer4%report(nsubsteps=1, message="timer4           :")
-         !call timer5%report(nsubsteps=1, message="timer5           :")
+         !$omp parallel do default(private) schedule(static)&
+         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
+         !$omp firstprivate(ntot, n1, n2, dt) 
+         do i = n1+1, ntot
+            if (loverlap(i)) then
+               ibegix = ibegx(i) + 1_I8B
+               iendix = iendx(i) - 1_I8B
+               lencounter1(:) = .false.
+               where(llist1(ibegix:iendix)) lencounter1(ext_ind_true(ibegix:iendix)) = .true.
+               ii = i - n1
+               call encounter_check_sweep_check_all_one(ii, n1, x2(1,ii), x2(2,ii), x2(3,ii), v2(1,ii), v2(2,ii), v2(3,ii), &
+                                                                x1(1, :), x1(2, :), x1(3, :), v1(1, :), v1(2, :), v1(3, :), &
+                                                                renc2(ii), renc1(:), dt, ind_arr, lencounter1(:), &
+                                                                lenc(i)%nenc, lenc(i)%lvdotr, lenc(i)%index2, lenc(i)%index1)
+            end if
+         end do
+         !$omp end parallel do
 
+         ! call timer1%stop()
+         ! call timer1%report(nsubsteps=1, message="timer1           :")
+         ! call timer2%report(nsubsteps=1, message="timer2           :")
+         ! call timer3%report(nsubsteps=1, message="timer3           :")
+         ! call timer4%report(nsubsteps=1, message="timer4           :")
+         ! call timer5%report(nsubsteps=1, message="timer5           :")
       end associate
 
       call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2, lvdotr)
@@ -695,32 +659,52 @@ subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1,
       return
    end subroutine encounter_check_sweep_aabb_double_list_2
 
-   pure subroutine encounter_check_sweep_check_one(x1,y1,z1,x2,y2,z2,vx1,vy1,vz1,vx2,vy2,vz2,renc1,renc2,dt,lencounter,lvdotr)
-      !$omp declare simd(encounter_check_sweep_check_one)
+
+   pure subroutine encounter_check_sweep_check_all_one(i, n, xi, yi, zi, vxi, vyi, vzi, x, y, z, vx, vy, vz, renci, renc, dt, ind_arr, lgood, nenci, lvdotr, index1, index2)
       implicit none
       ! Arguments
-      real(DP), intent(in)  :: x1,y1,z1
-      real(DP), intent(in)  :: x2,y2,z2
-      real(DP), intent(in)  :: vx1,vy1,vz1
-      real(DP), intent(in)  :: vx2,vy2,vz2
-      real(DP), intent(in)  :: renc1, renc2
-      real(DP), intent(in)  :: dt
-      logical,  intent(out) :: lencounter
-      logical,  intent(out) :: lvdotr
+      integer(I4B),                       intent(in)  :: i
+      integer(I4B),                       intent(in)  :: n
+      real(DP),                           intent(in)  :: xi, yi, zi
+      real(DP),                           intent(in)  :: vxi, vyi, vzi
+      real(DP),             dimension(:), intent(in)  :: x, y, z
+      real(DP),             dimension(:), intent(in)  :: vx, vy, vz
+      real(DP),                           intent(in)  :: renci
+      real(DP),             dimension(:), intent(in)  :: renc
+      real(DP),                           intent(in)  :: dt
+      integer(I4B),         dimension(:), intent(in)  :: ind_arr
+      logical,              dimension(:), intent(in)  :: lgood
+      integer(I8B),                       intent(out) :: nenci
+      logical, allocatable, dimension(:), intent(inout) :: lvdotr
+      integer(I4B), allocatable, dimension(:), intent(inout) :: index1, index2
       ! Internals
-      real(DP)  :: renc12,xr, yr, zr, vxr, vyr, vzr
+      integer(I4B) :: j
+      integer(I8B) :: k
+      real(DP) :: xr, yr, zr, vxr, vyr, vzr, renc12
+      logical, dimension(n) :: lencounteri, lvdotri
 
-      xr = x2 - x1
-      yr = y2 - y1
-      zr = z2 - z1
-      vxr = vx2 - vx1
-      vyr = vy2 - vy1
-      vzr = vz2 - vz1
-      renc12 = renc1 + renc2
-      call encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc12, dt, lencounter, lvdotr) 
+      lencounteri(:) = .false.
+      do concurrent(j = 1:n, lgood(j))
+         xr = x(j) - xi
+         yr = y(j) - yi
+         zr = z(j) - zi
+         vxr = vx(j) - vxi
+         vyr = vy(j) - vyi
+         vzr = vz(j) - vzi
+         renc12 = renci + renc(j)
+         call encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc12, dt, lencounteri(j), lvdotri(j))
+      end do
+      nenci = count(lencounteri(1:n))
+      if (nenci > 0_I8B) then
+         allocate(lvdotr(nenci), index1(nenci), index2(nenci))
+         lvdotr(:) = pack(lvdotri(1:n), lencounteri(1:n)) 
+         index1(:) = i
+         index2(:) = pack(ind_arr(1:n), lencounteri(1:n)) 
+      end if
 
       return
-   end subroutine encounter_check_sweep_check_one
+   end subroutine encounter_check_sweep_check_all_one
+
 
    subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc)
       !! author: David A. Minton

From e93ffe79e78ae03dc907040fe3bd62d8154189ea Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Tue, 23 Nov 2021 11:13:57 -0500
Subject: [PATCH 14/24] Major restructuring of encounter check subroutines.
 Rationallized the order of output arguments (nenc, index1, index2, lvdotr
 everywhere). Re-wrote single list in the style of the double list sweeper.
 The test case *almost* matches (it's off by one encounter)

---
 src/encounter/encounter_check.f90   | 908 ++++++++++------------------
 src/modules/encounter_classes.f90   |  50 +-
 src/rmvs/rmvs_encounter_check.f90   |   2 +-
 src/symba/symba_encounter_check.f90 |   6 +-
 4 files changed, 365 insertions(+), 601 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index ce3871bd0..360c01113 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -46,7 +46,7 @@ module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc
    end subroutine encounter_check_all
 
 
-   module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, lvdotr, index1, index2, nenc)
+   module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies. Choose between the standard triangular or the Sort & Sweep method based on user inputs
@@ -59,10 +59,10 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, lvdotr, i
       real(DP),     dimension(:,:),            intent(in)    :: v      !! Velocity vectors of massive bodies
       real(DP),     dimension(:),              intent(in)    :: renc   !! Critical radii of massive bodies that defines an encounter 
       real(DP),                                intent(in)    :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
+      logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       type(interaction_timer), save :: itimer
       logical, save :: lfirst = .true.
@@ -86,9 +86,9 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, lvdotr, i
       end if
 
       if (param%lencounter_sas_plpl) then
-         call encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, lvdotr, index1, index2, nenc) 
+         call encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, nenc, index1, index2, lvdotr) 
       else
-         call encounter_check_all_triangular_plpl(npl, x, v, renc, dt, lvdotr, index1, index2, nenc) 
+         call encounter_check_all_triangular_plpl(npl, x, v, renc, dt, nenc, index1, index2, lvdotr) 
       end if
 
       if (skipit) then
@@ -106,7 +106,7 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, lvdotr, i
    end subroutine encounter_check_all_plpl
 
 
-   module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, lvdotr, index1, index2, nenc)
+   module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between fully interacting massive bodies partially interacting massive bodies. Choose between the standard triangular or the Sort & Sweep method based on user inputs
@@ -123,10 +123,10 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       real(DP),     dimension(:),              intent(in)    :: rencm  !! Critical radii of fully interacting massive bodies that defines an encounter
       real(DP),     dimension(:),              intent(in)    :: renct  !! Critical radii of partially interacting massive bodies that defines an encounter
       real(DP),                                intent(in)    :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
+      logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       type(interaction_timer), save :: itimer
       logical, save :: lfirst = .true.
@@ -169,12 +169,12 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
 
       ! Start with the pl-pl group
       call timer%start()
-      call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, lvdotr, index1, index2, nenc)
+      call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, nenc, index1, index2, lvdotr)
 
       if (param%lencounter_sas_plpl) then
-         call encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_lvdotr, plmplt_index1, plmplt_index2, plmplt_nenc)
+         call encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr)
       else
-         call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_lvdotr, plmplt_index1, plmplt_index2, plmplt_nenc) 
+         call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr) 
       end if
       call timer%stop()
       call timer%report(nsubsteps=1, message="Encounter check  :")
@@ -222,7 +222,7 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
    end subroutine encounter_check_all_plplm
 
 
-   module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc)
+   module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. Choose between the standard triangular or the Sort & Sweep method based on user inputs
@@ -238,10 +238,10 @@ module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp,
       real(DP),     dimension(:,:),            intent(in)    :: vtp    !! Velocity vectors of test particles
       real(DP),     dimension(:),              intent(in)    :: renc   !! Critical radii of massive bodies that defines an encounter
       real(DP),                                intent(in)    :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
+      logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       type(interaction_timer), save :: itimer
       logical, save :: lfirst = .true.
@@ -271,9 +271,9 @@ module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp,
       end if
 
       if (param%lencounter_sas_pltp) then
-         call encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc)
+         call encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr)
       else
-         call encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc) 
+         call encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr) 
       end if
 
       if (.not.lfirst .and. param%ladaptive_encounters_pltp .and. npltp > 0) then 
@@ -284,108 +284,7 @@ module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp,
    end subroutine encounter_check_all_pltp
 
 
-   pure subroutine encounter_check_reduce_broadphase(n, nenc, index1, index2, lencounter, lvdotr)
-      !! author: David A. Minton
-      !!
-      !! Takes the candidate encounter lists that came out of the broad phase and narrow it down to the true encounters
-      implicit none
-      ! Arguments
-      integer(I4B),                            intent(in)    :: n          !! Number of bodies 
-      integer(I8B),                            intent(inout) :: nenc       !! Number of encountering bodies (input is the broad phase value, output is the final narrow phase value)
-      integer(I4B), dimension(:), allocatable, intent(inout) :: index1     !! List of indices for body 1 in each encounter
-      integer(I4B), dimension(:), allocatable, intent(inout) :: index2     !! List of indices for body 2 in each encounter
-      logical,      dimension(:), allocatable, intent(inout) :: lencounter !! Logical flag indicating which of the pairs identified in the broad phase was selected in the narrow phase
-      logical,      dimension(:), allocatable, intent(inout) :: lvdotr     !! Logical flag indicating the sign of v .dot. x
-      ! Internals
-      integer(I4B) :: i, i0, j
-      integer(I8B) :: k, klo, khi, nenci
-      integer(I4B), dimension(:), allocatable :: itmp
-      integer(I8B), dimension(:), allocatable :: ind
-      integer(I8B), dimension(n) :: ibeg, iend
-      logical, dimension(:), allocatable :: ltmp
-
-      nenc = count(lencounter(:)) ! Count the true number of encounters
-      if (nenc == 0) then
-         if (allocated(index1)) deallocate(index1)
-         if (allocated(index2)) deallocate(index2)
-         if (allocated(lvdotr)) deallocate(lvdotr)
-         return
-      end if
-
-      if (any(.not.lencounter(:))) then
-         allocate(itmp(nenc))
-         itmp(:) = pack(index1(:), lencounter(:))
-         call move_alloc(itmp, index1)
-
-         allocate(itmp(nenc))
-         itmp(:) = pack(index2(:), lencounter(:))
-         call move_alloc(itmp, index2)
-
-         allocate(ltmp(nenc))
-         ltmp(:) = pack(lvdotr(:), lencounter(:))
-         call move_alloc(ltmp, lvdotr)
-
-         if (allocated(lencounter)) deallocate(lencounter)
-         allocate(lencounter(nenc))
-         lencounter(:) = .true.
-      end if
-
-      call util_sort(index1, ind)
-      call util_sort_rearrange(index1, ind, nenc)
-      call util_sort_rearrange(index2, ind, nenc)
-      call util_sort_rearrange(lvdotr, ind, nenc)
-
-      ! Get the bounds on the bodies in the first index
-      ibeg(:) = n
-      iend(:) = 1
-      i0 = index1(1) 
-      ibeg(i0) = 1
-      do k = 2, nenc 
-         i = index1(k)
-         if (i /= i0) then
-            iend(i0) = k - 1
-            ibeg(i) = k
-            i0 = i
-         end if
-         if (k == nenc) iend(i) = k
-      end do
-
-      ! Sort on the second index and remove duplicates 
-      if (allocated(itmp)) deallocate(itmp)
-      allocate(itmp, source=index2)
-      do concurrent(i = 1:n, iend(i) - ibeg(i) > 0)
-         klo = ibeg(i)
-         khi = iend(i)
-         nenci = khi - klo + 1
-         if (allocated(ind)) deallocate(ind)
-         call util_sort(index2(klo:khi), ind)
-         index2(klo:khi) = itmp(klo - 1 + ind(:))
-         do j = klo + 1, khi
-            if (index2(j) == index2(j - 1)) lencounter(j) = .false. 
-         end do
-      end do
-
-      if (count(lencounter(:)) == nenc) return
-      nenc = count(lencounter(:)) ! Count the true number of encounters
-
-      if (allocated(itmp)) deallocate(itmp)
-      allocate(itmp(nenc))
-      itmp(:) = pack(index1(:), lencounter(:))
-      call move_alloc(itmp, index1)
-
-      allocate(itmp(nenc))
-      itmp(:) = pack(index2(:), lencounter(:))
-      call move_alloc(itmp, index2)
-
-      allocate(ltmp(nenc))
-      ltmp(:) = pack(lvdotr(:), lencounter(:))
-      call move_alloc(ltmp, lvdotr)
-
-      return
-   end subroutine encounter_check_reduce_broadphase
-
-
-   subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, lvdotr, index1, index2, nenc)
+   subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies. 
@@ -399,10 +298,10 @@ subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, lvdotr,
       real(DP),     dimension(:,:),            intent(in)  :: v      !! Velocity vectors of massive bodies
       real(DP),     dimension(:),              intent(in)  :: renc   !! Critical radii of massive bodies that defines an encounter 
       real(DP),                                intent(in)  :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
+      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       integer(I4B) :: i, dim, n
       integer(I4B), save :: npl_last = 0
@@ -436,24 +335,13 @@ subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, lvdotr,
       end do
       !$omp end parallel do 
 
-      call boundingbox%sweep(npl, nenc, index1, index2)
-
-      if (nenc > 0_I8B) then
-         ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
-         allocate(lencounter(nenc))
-         allocate(lvdotr(nenc))
-
-         call encounter_check_all(nenc, index1, index2, x, v, x, v, renc, renc, dt, lencounter, lvdotr)
-
-         call encounter_check_reduce_broadphase(npl, nenc, index1, index2, lencounter, lvdotr)
-         deallocate(lencounter)
-      end if
+      call boundingbox%sweep(npl, x, v, renc, dt, nenc, index1, index2, lvdotr) 
 
       return
    end subroutine encounter_check_all_sort_and_sweep_plpl
 
 
-   subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, lvdotr, index1, index2, nenc)
+   subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. 
@@ -471,10 +359,10 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
       real(DP),     dimension(:),              intent(in)  :: rencm  !! Critical radii of fully interacting massive bodies that defines an encounter
       real(DP),     dimension(:),              intent(in)  :: renct  !! Critical radii of partially interacting massive bodies that defines an encounter
       real(DP),                                intent(in)  :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out) :: nenc   !! Total number of encounter
+      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       type(encounter_bounding_box), save :: boundingbox
       integer(I4B) :: i, dim, n, ntot
@@ -521,192 +409,13 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
       end do
       !$omp end parallel do
 
-      call encounter_check_sweep_aabb_double_list_2(boundingbox, nplm, nplt, nenc, index1, index2, xplm, vplm, xplt, vplt, rencm, renct, dt, lvdotr) 
-
-      !call boundingbox%sweep(nplm, nplt, nenc, index1, index2)
-
-      ! if (nenc > 0_I8B) then
-      !    ! Shift tiny body indices back into the range of the input position and velocity arrays
-      !    !index2(:) = index2(:) - nplm
-
-      !    ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
-      !    allocate(lencounter(nenc))
-      !    allocate(lvdotr(nenc))
+      call boundingbox%sweep(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr) 
 
-      !    call encounter_check_all(nenc, index1, index2, xplm, vplm, xplt, vplt, rencm, renct, dt, lencounter, lvdotr)
-
-      !    call encounter_check_reduce_broadphase(ntot, nenc, index1, index2, lencounter, lvdotr)
-      ! end if
       return
    end subroutine encounter_check_all_sort_and_sweep_plplm
 
 
-   subroutine encounter_check_sweep_aabb_double_list_2(self, n1, n2, nenc, index1, index2, x1, v1, x2, v2, renc1, renc2, dt, lvdotr)
-      !! author: David A. Minton
-      !!
-      !! Sweeps the sorted bounding box extents and returns the true encounters (combines broad and narrow phases)
-      implicit none
-      ! Arguments
-      class(encounter_bounding_box),           intent(inout) :: self       !! Multi-dimensional bounding box structure
-      integer(I4B),                            intent(in)    :: n1         !! Number of bodies 1
-      integer(I4B),                            intent(in)    :: n2         !! Number of bodies 2
-      integer(I8B),                            intent(out)   :: nenc       !! Total number of encounter candidates
-      integer(I4B), dimension(:), allocatable, intent(out)   :: index1     !! List of indices for body 1 in each encounter candidate pair
-      integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for body 2 in each encounter candidate pair
-      real(DP),     dimension(:,:),            intent(in)    :: x1, v1     !! Array of indices of bodies 1
-      real(DP),     dimension(:,:),            intent(in)    :: x2, v2     !! Array of indices of bodies 2
-      real(DP),     dimension(:),              intent(in)    :: renc1      !! Radius of encounter regions of bodies 1
-      real(DP),     dimension(:),              intent(in)    :: renc2      !! Radius of encounter regions of bodies 2
-      real(DP),                                intent(in)    :: dt         !! Step size
-      logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
-      ! Internals
-      integer(I4B) :: ii, i, j, jj, ntot, dim
-      integer(I8B) :: k, kk
-      logical, dimension(n1+n2) :: loverlap
-      logical, dimension(n1) :: lencounter1
-      logical, dimension(n2) :: lencounter2
-      logical, dimension(:), allocatable  :: lencounter, lvdotri
-      logical, dimension(:), allocatable :: lencounterj, lenctrue, ltmp, llist1
-      integer(I4B), dimension(:), allocatable :: ext_ind_true
-      type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
-      integer(I4B), dimension(:), allocatable, save :: ind_arr
-      integer(I8B) :: ibegix, iendix
-      integer(I8B), pointer :: ibegx, ibegy
-      integer(I4B), dimension(:), allocatable :: index1i, index2i, itmp, box
-      type(walltimer) :: timer1, timer2, timer3, timer4, timer5
-      logical, save :: lfirst = .true.
-
-      if (lfirst) then
-         call timer1%reset()
-         call timer2%reset()
-         call timer3%reset()
-         call timer4%reset()
-         call timer5%reset()
-         lfirst = .false.
-      end if
-
-      ntot = n1 + n2
-      call util_index_array(ind_arr, ntot)
-
-      associate(ext_ind => self%aabb(1)%ind(:), ibegx => self%aabb(1)%ibeg(:), iendx => self%aabb(1)%iend(:))
-         ! Sweep the intervals for each of the massive bodies along one dimension
-         ! This will build a ragged pair of index lists inside of the lenc data structure
-         allocate(ext_ind_true, mold=ext_ind)
-         allocate(llist1(size(ext_ind)))
-         where(ext_ind(:) > ntot)
-            ext_ind_true(:) = ext_ind(:) - ntot
-         elsewhere
-            ext_ind_true(:) = ext_ind(:)
-         endwhere
-         llist1(:) = ext_ind_true(:) <= n1
-
-         loverlap(:) = (iendx(:) + 1) > (ibegx(:) - 1)
-         where(.not.loverlap(:)) lenc(:)%nenc = 0
-
-         ! call timer1%start()
-         !$omp parallel do default(private) schedule(static)&
-         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
-         !$omp firstprivate(ntot, n1, n2, dt) 
-         do i = 1, n1
-            if (loverlap(i)) then
-               ibegix = ibegx(i) + 1_I8B
-               iendix = iendx(i) - 1_I8B
-
-               lencounter2(:) = .false.
-               where(.not.llist1(ibegix:iendix)) lencounter2(ext_ind_true(ibegix:iendix) - n1) = .true.
-               call encounter_check_sweep_check_all_one(i, n2, x1(1,i), x1(2,i), x1(3,i), v1(1,i), v1(2,i), v1(3,i), &
-                                                               x2(1,:), x2(2,:), x2(3,:), v2(1,:), v2(2,:), v2(3,:), &
-                                                               renc1(i), renc2(:), dt, ind_arr, lencounter2(:), &
-                                                               lenc(i)%nenc, lenc(i)%lvdotr, lenc(i)%index1, lenc(i)%index2)
-             end if
-         end do
-         !$omp end parallel do
-
-         !$omp parallel do default(private) schedule(static)&
-         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
-         !$omp firstprivate(ntot, n1, n2, dt) 
-         do i = n1+1, ntot
-            if (loverlap(i)) then
-               ibegix = ibegx(i) + 1_I8B
-               iendix = iendx(i) - 1_I8B
-               lencounter1(:) = .false.
-               where(llist1(ibegix:iendix)) lencounter1(ext_ind_true(ibegix:iendix)) = .true.
-               ii = i - n1
-               call encounter_check_sweep_check_all_one(ii, n1, x2(1,ii), x2(2,ii), x2(3,ii), v2(1,ii), v2(2,ii), v2(3,ii), &
-                                                                x1(1, :), x1(2, :), x1(3, :), v1(1, :), v1(2, :), v1(3, :), &
-                                                                renc2(ii), renc1(:), dt, ind_arr, lencounter1(:), &
-                                                                lenc(i)%nenc, lenc(i)%lvdotr, lenc(i)%index2, lenc(i)%index1)
-            end if
-         end do
-         !$omp end parallel do
-
-         ! call timer1%stop()
-         ! call timer1%report(nsubsteps=1, message="timer1           :")
-         ! call timer2%report(nsubsteps=1, message="timer2           :")
-         ! call timer3%report(nsubsteps=1, message="timer3           :")
-         ! call timer4%report(nsubsteps=1, message="timer4           :")
-         ! call timer5%report(nsubsteps=1, message="timer5           :")
-      end associate
-
-      call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2, lvdotr)
-
-      if (allocated(lencounter)) deallocate(lencounter)
-      allocate(lencounter(nenc))
-      lencounter(:) = .true.
-
-      call encounter_check_reduce_broadphase(ntot, nenc, index1, index2, lencounter, lvdotr)
-
-      return
-   end subroutine encounter_check_sweep_aabb_double_list_2
-
-
-   pure subroutine encounter_check_sweep_check_all_one(i, n, xi, yi, zi, vxi, vyi, vzi, x, y, z, vx, vy, vz, renci, renc, dt, ind_arr, lgood, nenci, lvdotr, index1, index2)
-      implicit none
-      ! Arguments
-      integer(I4B),                       intent(in)  :: i
-      integer(I4B),                       intent(in)  :: n
-      real(DP),                           intent(in)  :: xi, yi, zi
-      real(DP),                           intent(in)  :: vxi, vyi, vzi
-      real(DP),             dimension(:), intent(in)  :: x, y, z
-      real(DP),             dimension(:), intent(in)  :: vx, vy, vz
-      real(DP),                           intent(in)  :: renci
-      real(DP),             dimension(:), intent(in)  :: renc
-      real(DP),                           intent(in)  :: dt
-      integer(I4B),         dimension(:), intent(in)  :: ind_arr
-      logical,              dimension(:), intent(in)  :: lgood
-      integer(I8B),                       intent(out) :: nenci
-      logical, allocatable, dimension(:), intent(inout) :: lvdotr
-      integer(I4B), allocatable, dimension(:), intent(inout) :: index1, index2
-      ! Internals
-      integer(I4B) :: j
-      integer(I8B) :: k
-      real(DP) :: xr, yr, zr, vxr, vyr, vzr, renc12
-      logical, dimension(n) :: lencounteri, lvdotri
-
-      lencounteri(:) = .false.
-      do concurrent(j = 1:n, lgood(j))
-         xr = x(j) - xi
-         yr = y(j) - yi
-         zr = z(j) - zi
-         vxr = vx(j) - vxi
-         vyr = vy(j) - vyi
-         vzr = vz(j) - vzi
-         renc12 = renci + renc(j)
-         call encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc12, dt, lencounteri(j), lvdotri(j))
-      end do
-      nenci = count(lencounteri(1:n))
-      if (nenci > 0_I8B) then
-         allocate(lvdotr(nenci), index1(nenci), index2(nenci))
-         lvdotr(:) = pack(lvdotri(1:n), lencounteri(1:n)) 
-         index1(:) = i
-         index2(:) = pack(ind_arr(1:n), lencounteri(1:n)) 
-      end if
-
-      return
-   end subroutine encounter_check_sweep_check_all_one
-
-
-   subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc)
+   subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. 
@@ -723,10 +432,10 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
       real(DP),     dimension(:,:),            intent(in)  :: vtp    !! Velocity vectors of massive bodies
       real(DP),     dimension(:),              intent(in)  :: renc   !! Critical radii of massive bodies that defines an encounter
       real(DP),                                intent(in)  :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out) :: nenc   !! Total number of encounter
+      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       type(encounter_bounding_box), save :: boundingbox
       integer(I4B) :: i, dim, n, ntot
@@ -773,41 +482,81 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
       end do
       !$omp end parallel do
 
-      call boundingbox%sweep(npl, ntp, nenc, index1, index2)
+      call boundingbox%sweep(npl, ntp, xpl, vpl, xtp, vtp, renc, renctp, dt, nenc, index1, index2, lvdotr) 
 
-      if (nenc > 0_I8B) then
-         ! Shift test particle indices back into the proper range
-         index2(:) = index2(:) - npl
-
-         ! Now that we have identified potential pairs, use the narrow-phase process to get the final values
-         allocate(lencounter(nenc))
-         allocate(lvdotr(nenc))
-         renctp(:) = 0.0_DP
+      return
+   end subroutine encounter_check_all_sort_and_sweep_pltp
 
-         call encounter_check_all(nenc, index1, index2, xpl, vpl, xtp, vtp, renc, renctp, dt, lencounter, lvdotr)
 
-         call encounter_check_reduce_broadphase(ntot, nenc, index1, index2, lencounter, lvdotr)
+   pure subroutine encounter_check_all_sweep_one(i, n, xi, yi, zi, vxi, vyi, vzi, x, y, z, vx, vy, vz, renci, renc, dt, ind_arr, lgood, nenci, index1, index2, lvdotr)
+      !! author: David A. Minton
+      !!
+      !! Check for encounters between the ith body and all other bodies.
+      !! This is used in the narrow phase of the sort & sweep algorithm
+      implicit none
+      ! Arguments
+      integer(I4B),                            intent(in)    :: i             !! Index of the ith body that is being checked
+      integer(I4B),                            intent(in)    :: n             !! Total number of bodies being checked
+      real(DP),                                intent(in)    :: xi, yi, zi    !! Position vector components of the ith body
+      real(DP),                                intent(in)    :: vxi, vyi, vzi !! Velocity vector components of the ith body
+      real(DP),     dimension(:),              intent(in)    :: x, y, z       !! Arrays of position vector components of all bodies
+      real(DP),     dimension(:),              intent(in)    :: vx, vy, vz    !! Arrays of velocity vector components of all bodies
+      real(DP),                                intent(in)    :: renci         !! Encounter radius of the ith body
+      real(DP),     dimension(:),              intent(in)    :: renc          !! Array of encounter radii of all bodies
+      real(DP),                                intent(in)    :: dt            !! Step size
+      integer(I4B), dimension(:),              intent(in)    :: ind_arr       !! Index array [1, 2, ..., n]
+      logical,      dimension(:),              intent(in)    :: lgood         !! Logical array mask where true values correspond to bodies selected in the broad phase
+      integer(I8B),                            intent(out)   :: nenci         !! Total number of encountering bodies
+      integer(I4B), dimension(:), allocatable, intent(inout) :: index1        !! Array of indices of the ith body of size nenci [i, i, ..., i]
+      integer(I4B), dimension(:), allocatable, intent(inout) :: index2        !! Array of indices of the encountering bodies of size nenci 
+      logical,      dimension(:), allocatable, intent(inout) :: lvdotr        !! v.dot.r direction array
+      ! Internals
+      integer(I4B) :: j
+      integer(I8B) :: k
+      real(DP) :: xr, yr, zr, vxr, vyr, vzr, renc12
+      logical, dimension(n) :: lencounteri, lvdotri
 
+      lencounteri(:) = .false.
+      do concurrent(j = 1:n, lgood(j))
+         xr = x(j) - xi
+         yr = y(j) - yi
+         zr = z(j) - zi
+         vxr = vx(j) - vxi
+         vyr = vy(j) - vyi
+         vzr = vz(j) - vzi
+         renc12 = renci + renc(j)
+         call encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc12, dt, lencounteri(j), lvdotri(j))
+      end do
+      nenci = count(lencounteri(1:n))
+      if (nenci > 0_I8B) then
+         allocate(lvdotr(nenci), index1(nenci), index2(nenci))
+         lvdotr(:) = pack(lvdotri(1:n), lencounteri(1:n)) 
+         index1(:) = i
+         index2(:) = pack(ind_arr(1:n), lencounteri(1:n)) 
       end if
 
       return
-   end subroutine encounter_check_all_sort_and_sweep_pltp
+   end subroutine encounter_check_all_sweep_one
 
 
    pure subroutine encounter_check_all_triangular_one(i, n, xi, yi, zi, vxi, vyi, vzi, x, y, z, vx, vy, vz, renci, renc, dt, ind_arr, lenci)
+      !! author: David A. Minton
+      !!
+      !! Check for encounters between the ith body and all other bodies.
+      !! This is the upper triangular (double loop) version.
       implicit none
       ! Arguments
-      integer(I4B),                       intent(in)  :: i
-      integer(I4B),                       intent(in)  :: n
-      real(DP),                           intent(in)  :: xi, yi, zi
-      real(DP),                           intent(in)  :: vxi, vyi, vzi
-      real(DP),             dimension(:), intent(in)  :: x, y, z
-      real(DP),             dimension(:), intent(in)  :: vx, vy, vz
-      real(DP),                           intent(in)  :: renci
-      real(DP),             dimension(:), intent(in)  :: renc
-      real(DP),                           intent(in)  :: dt
-      integer(I4B),         dimension(:), intent(in)  :: ind_arr
-      type(encounter_list),               intent(out) :: lenci
+      integer(I4B),                       intent(in)  :: i             !! Index of the ith body that is being checked
+      integer(I4B),                       intent(in)  :: n             !! Total number of bodies being checked
+      real(DP),                           intent(in)  :: xi, yi, zi    !! Position vector components of the ith body
+      real(DP),                           intent(in)  :: vxi, vyi, vzi !! Velocity vector components of the ith body
+      real(DP),             dimension(:), intent(in)  :: x, y, z       !! Arrays of position vector components of all bodies
+      real(DP),             dimension(:), intent(in)  :: vx, vy, vz    !! Arrays of velocity vector components of all bodies
+      real(DP),                           intent(in)  :: renci         !! Encounter radius of the ith body
+      real(DP),             dimension(:), intent(in)  :: renc          !! Array of encounter radii of all bodies
+      real(DP),                           intent(in)  :: dt            !! Step size
+      integer(I4B),         dimension(:), intent(in)  :: ind_arr       !! Index array [1, 2, ..., n]
+      type(encounter_list),               intent(out) :: lenci         !! Output encounter lists containing number of encounters, the v.dot.r direction array, and the index list of encountering bodies 
       ! Internals
       integer(I4B) :: j
       integer(I8B) :: k, nenci
@@ -836,7 +585,7 @@ pure subroutine encounter_check_all_triangular_one(i, n, xi, yi, zi, vxi, vyi, v
    end subroutine encounter_check_all_triangular_one
 
 
-   subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, lvdotr, index1, index2, nenc)
+   subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies. Split off from the main subroutine for performance
@@ -848,10 +597,10 @@ subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, lvdotr, inde
       real(DP),     dimension(:,:),            intent(in)  :: v      !! Velocity vectors of massive bodies
       real(DP),     dimension(:),              intent(in)  :: renc  !! Critical radii of massive bodies that defines an encounter 
       real(DP),                                intent(in)  :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
+      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       integer(I4B) :: i, j, k, nenci, j0, j1
       real(DP) :: xr, yr, zr, vxr, vyr, vzr, renc12
@@ -881,7 +630,7 @@ subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, lvdotr, inde
    end subroutine encounter_check_all_triangular_plpl
 
 
-   subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, lvdotr, index1, index2, nenc)
+   subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. Split off from the main subroutine for performance
@@ -897,10 +646,10 @@ subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vp
       real(DP),     dimension(:),              intent(in)  :: rencm  !! Critical radii of fully interacting massive bodies that defines an encounter
       real(DP),     dimension(:),              intent(in)  :: renct  !! Critical radii of partially interacting massive bodies that defines an encounter
       real(DP),                                intent(in)  :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
+      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       integer(I4B) :: i
       logical, dimension(nplt) :: lencounteri, lvdotri
@@ -929,7 +678,7 @@ subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vp
    end subroutine encounter_check_all_triangular_plplm
 
 
-   subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc)
+   subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. Split off from the main subroutine for performance
@@ -944,10 +693,10 @@ subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, ren
       real(DP),     dimension(:,:),            intent(in)  :: vtp    !! Velocity vectors of massive bodies
       real(DP),     dimension(:),              intent(in)  :: renc   !! Critical radii of massive bodies that defines an encounter
       real(DP),                                intent(in)  :: dt     !! Step size
-      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
+      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index2 !! List of indices for body 2 in each encounter
-      integer(I8B),                            intent(out) :: nenc   !! Total number of encounters
+      logical,      dimension(:), allocatable, intent(out) :: lvdotr !! Logical flag indicating the sign of v .dot. x
       ! Internals
       integer(I4B) :: i
       logical, dimension(ntp) :: lencounteri, lvdotri
@@ -1076,30 +825,89 @@ module subroutine encounter_check_collapse_ragged_list(ragged_list, n1, nenc, in
    end subroutine encounter_check_collapse_ragged_list
 
 
-   pure subroutine encounter_check_make_ragged_list(lencounteri, ind_arr, i, lenci)
+   subroutine encounter_check_remove_duplicates(n, nenc, index1, index2, lvdotr)
+      !! author: David A. Minton
+      !!
+      !! Takes the candidate encounter lists that came out of the sort & sweep method and remove any duplicates.
       implicit none
       ! Arguments
-      logical,      dimension(:),              intent(in)  :: lencounteri !! Array of logicals indicating which bodies are candidates for encounter with body i
-      integer(I4B), dimension(:),              intent(in)  :: ind_arr     !! Index array 
-      integer(I4B),                            intent(in)  :: i           !! Index value of body i that will fill index1 
-      type(encounter_list),                    intent(out) :: lenci       !! The ith row of the ragged encounter list
+      integer(I4B),                            intent(in)    :: n          !! Number of bodies 
+      integer(I8B),                            intent(inout) :: nenc       !! Number of encountering bodies (input is the broad phase value, output is the final narrow phase value)
+      integer(I4B), dimension(:), allocatable, intent(inout) :: index1     !! List of indices for body 1 in each encounter
+      integer(I4B), dimension(:), allocatable, intent(inout) :: index2     !! List of indices for body 2 in each encounter
+      logical,      dimension(:), allocatable, intent(inout) :: lvdotr     !! Logical flag indicating the sign of v .dot. x
       ! Internals
-      integer(I8B) :: k
+      integer(I4B) :: i, i0
+      integer(I8B) :: j, k, klo, khi, nenci
+      integer(I4B), dimension(:), allocatable :: itmp
+      integer(I8B), dimension(:), allocatable :: ind
+      integer(I8B), dimension(n) :: ibeg, iend
+      logical, dimension(:), allocatable :: ltmp
+      logical, dimension(nenc) :: lencounter
 
-      lenci%nenc = count(lencounteri(:))
-      if (lenci%nenc > 0_I8B) then
-         if (allocated(lenci%index1)) deallocate(lenci%index1)
-         if (allocated(lenci%index2)) deallocate(lenci%index2)
-         allocate(lenci%index1(lenci%nenc))
-         allocate(lenci%index2(lenci%nenc))
-         lenci%index1(:) = [(i, k = 1_I8B, lenci%nenc)]
-         lenci%index2(:) = pack(ind_arr(:), lencounteri(:)) 
+      if (nenc == 0) then
+         if (allocated(index1)) deallocate(index1)
+         if (allocated(index2)) deallocate(index2)
+         if (allocated(lvdotr)) deallocate(lvdotr)
+         return
       end if
 
+      call util_sort(index1, ind)
+      call util_sort_rearrange(index1, ind, nenc)
+      call util_sort_rearrange(index2, ind, nenc)
+      call util_sort_rearrange(lvdotr, ind, nenc)
+
+      ! Get the bounds on the bodies in the first index
+      ibeg(:) = n
+      iend(:) = 1_I8B
+      i0 = index1(1) 
+      ibeg(i0) = 1_I8B
+      do k = 2_I8B, nenc 
+         i = index1(k)
+         if (i /= i0) then
+            iend(i0) = k - 1_I8B
+            ibeg(i) = k
+            i0 = i
+         end if
+         if (k == nenc) iend(i) = k
+      end do
+
+      lencounter(:) = .true.
+      ! Sort on the second index and remove duplicates 
+      if (allocated(itmp)) deallocate(itmp)
+      allocate(itmp, source=index2)
+      do concurrent(i = 1:n, iend(i) - ibeg(i) > 0_I8B)
+         klo = ibeg(i)
+         khi = iend(i)
+         nenci = khi - klo + 1_I8B
+         if (allocated(ind)) deallocate(ind)
+         call util_sort(index2(klo:khi), ind)
+         index2(klo:khi) = itmp(klo - 1_I8B + ind(:))
+         do j = klo + 1_I8B, khi
+            if (index2(j) == index2(j - 1_I8B)) lencounter(j) = .false. 
+         end do
+      end do
+
+      if (count(lencounter(:)) == nenc) return
+      nenc = count(lencounter(:)) ! Count the true number of encounters
+
+      if (allocated(itmp)) deallocate(itmp)
+      allocate(itmp(nenc))
+      itmp(:) = pack(index1(:), lencounter(:))
+      call move_alloc(itmp, index1)
+
+      allocate(itmp(nenc))
+      itmp(:) = pack(index2(:), lencounter(:))
+      call move_alloc(itmp, index2)
+
+      allocate(ltmp(nenc))
+      ltmp(:) = pack(lvdotr(:), lencounter(:))
+      call move_alloc(ltmp, lvdotr)
+
       return
-   end subroutine encounter_check_make_ragged_list
+   end subroutine encounter_check_remove_duplicates
+
 
-  
    module pure subroutine encounter_check_sort_aabb_1D(self, n, extent_arr)
       !! author: David A. Minton
       !!
@@ -1128,256 +936,202 @@ module pure subroutine encounter_check_sort_aabb_1D(self, n, extent_arr)
       return
    end subroutine encounter_check_sort_aabb_1D 
 
-   
-   module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, index1, index2)
+
+   module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x2, v2, renc1, renc2, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
-      !! Sweeps the sorted bounding box extents and returns the encounter candidates
+      !! Sweeps the sorted bounding box extents and returns the true encounters (combines broad and narrow phases)
+      !! Double list version (e.g. pl-tp or plm-plt)
       implicit none
       ! Arguments
-      class(encounter_bounding_box),           intent(inout) :: self     !! Multi-dimensional bounding box structure
-      integer(I4B),                            intent(in)    :: n1       !! Number of bodies 1
-      integer(I4B),                            intent(in)    :: n2       !! Number of bodies 2
-      integer(I8B),                            intent(out)   :: nenc     !! Total number of encounter candidates
-      integer(I4B), dimension(:), allocatable, intent(out)   :: index1   !! List of indices for body 1 in each encounter candidate pair
-      integer(I4B), dimension(:), allocatable, intent(out)   :: index2   !! List of indices for body 2 in each encounter candidate pair
+      class(encounter_bounding_box),           intent(inout) :: self       !! Multi-dimensional bounding box structure
+      integer(I4B),                            intent(in)    :: n1         !! Number of bodies 1
+      integer(I4B),                            intent(in)    :: n2         !! Number of bodies 2
+      real(DP),     dimension(:,:),            intent(in)    :: x1, v1     !! Array of position and velocity vectorrs for bodies 1
+      real(DP),     dimension(:,:),            intent(in)    :: x2, v2     !! Array of position and velocity vectorrs for bodies 2
+      real(DP),     dimension(:),              intent(in)    :: renc1      !! Radius of encounter regions of bodies 1
+      real(DP),     dimension(:),              intent(in)    :: renc2      !! Radius of encounter regions of bodies 2
+      real(DP),                                intent(in)    :: dt         !! Step size
+      integer(I8B),                            intent(out)   :: nenc       !! Total number of encounter candidates
+      integer(I4B), dimension(:), allocatable, intent(out)   :: index1     !! List of indices for body 1 in each encounter candidate pair
+      integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for body 2 in each encounter candidate pair
+      logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
-      integer(I4B) :: i, ntot, dim
+      integer(I4B) :: ii, i, ntot
       integer(I8B) :: k
+      logical, dimension(n1+n2) :: loverlap
+      logical, dimension(n1) :: lencounter1
+      logical, dimension(n2) :: lencounter2
+      logical, dimension(:), allocatable :: llist1
+      integer(I4B), dimension(:), allocatable :: ext_ind_true
       type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
-      integer(I8B), dimension(SWEEPDIM * (n1 + n2)) :: ibeg, iend
+      integer(I8B) :: ibegix, iendix
+      integer(I8B), pointer :: ibegx, iendx
+      type(walltimer) :: timer1, timer2, timer3, timer4, timer5
+      logical, save :: lfirst = .true.
+
+      if (lfirst) then
+         call timer1%reset()
+         call timer2%reset()
+         call timer3%reset()
+         call timer4%reset()
+         call timer5%reset()
+         lfirst = .false.
+      end if
 
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
-      do concurrent (dim=1:SWEEPDIM, i = 1:ntot)
-         ibeg((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%ibeg(i)
-         iend((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%iend(i)
-      end do
 
-      ! Sweep the intervals for each of the massive bodies along one dimension
-      ! This will build a ragged pair of index lists inside of the lenc data structure
-      call encounter_check_sweep_aabb_all_double_list(n1, n2, self%aabb(1)%ind(:), reshape(ibeg(:), [SWEEPDIM, ntot]), reshape(iend(:), [SWEEPDIM, ntot]), ind_arr(:), lenc(:))
-      
-      call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2)
-
-      ! Reorder the pairs and sort the first index in order to remove any duplicates
-      do concurrent(k = 1_I8B:nenc, index2(k) < index1(k))
-         i = index2(k)
-         index2(k) = index1(k)
-         index1(k) = i
-      end do
+      associate(ext_ind => self%aabb(1)%ind(:), ibegx => self%aabb(1)%ibeg(:), iendx => self%aabb(1)%iend(:))
+         ! Sweep the intervals for each of the massive bodies along one dimension
+         ! This will build a ragged pair of index lists inside of the lenc data structure
+         allocate(ext_ind_true, mold=ext_ind)
+         allocate(llist1(size(ext_ind)))
+         where(ext_ind(:) > ntot)
+            ext_ind_true(:) = ext_ind(:) - ntot
+         elsewhere
+            ext_ind_true(:) = ext_ind(:)
+         endwhere
+         llist1(:) = ext_ind_true(:) <= n1
 
-      return
-   end subroutine encounter_check_sweep_aabb_double_list
+         loverlap(:) = (iendx(:) + 1_I8B) > (ibegx(:) - 1_I8B)
+         where(.not.loverlap(:)) lenc(:)%nenc = 0
 
+         call timer1%start()
+         !$omp parallel do default(private) schedule(static)&
+         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
+         !$omp firstprivate(ntot, n1, n2, dt) 
+         do i = 1, n1
+            if (loverlap(i)) then
+               ibegix = ibegx(i) + 1_I8B
+               iendix = iendx(i) - 1_I8B
 
-   module subroutine encounter_check_sweep_aabb_single_list(self, n, nenc, index1, index2)
-      !! author: David A. Minton
-      !!
-      !! Sweeps the sorted bounding box extents and returns the encounter candidates. Mutual encounters
-      !! allowed. That is, all bodies are from the same list
-      implicit none
-      ! Arguments
-      class(encounter_bounding_box),           intent(inout) :: self    !! Multi-dimensional bounding box structure
-      integer(I4B),                            intent(in)    :: n       !! Number of bodies 1
-      integer(I8B),                            intent(out)   :: nenc    !! Total number of encounter candidates
-      integer(I4B), dimension(:), allocatable, intent(out)   :: index1  !! List of indices for body 1 in each encounter candidate pair
-      integer(I4B), dimension(:), allocatable, intent(out)   :: index2  !! List of indices for body 2 in each encounter candidate pair
-      !Internals
-      integer(I4B) :: i, dim
-      integer(I8B) :: k
-      type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
-      integer(I4B), dimension(:), allocatable, save :: ind_arr
-      integer(I8B), dimension(SWEEPDIM * n) :: ibeg, iend
+               lencounter2(:) = .false.
+               where(.not.llist1(ibegix:iendix)) lencounter2(ext_ind_true(ibegix:iendix) - n1) = .true.
+               call encounter_check_all_sweep_one(i, n2, x1(1,i), x1(2,i), x1(3,i), v1(1,i), v1(2,i), v1(3,i), &
+                                                               x2(1,:), x2(2,:), x2(3,:), v2(1,:), v2(2,:), v2(3,:), &
+                                                               renc1(i), renc2(:), dt, ind_arr, lencounter2(:), &
+                                                               lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
+             end if
+         end do
+         !$omp end parallel do
+         call timer1%stop()
 
-      call util_index_array(ind_arr, n)
-      do concurrent(dim = 1:SWEEPDIM, i = 1:n)
-         ibeg((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%ibeg(i)
-         iend((i - 1) * SWEEPDIM + dim) = self%aabb(dim)%iend(i)
-      end do
+         call timer2%start()
+         !$omp parallel do default(private) schedule(static)&
+         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
+         !$omp firstprivate(ntot, n1, dt) 
+         do i = n1+1, ntot
+            if (loverlap(i)) then
+               ibegix = ibegx(i) + 1_I8B
+               iendix = iendx(i) - 1_I8B
+               lencounter1(:) = .false.
+               where(llist1(ibegix:iendix)) lencounter1(ext_ind_true(ibegix:iendix)) = .true.
+               ii = i - n1
+               call encounter_check_all_sweep_one(ii, n1, x2(1,ii), x2(2,ii), x2(3,ii), v2(1,ii), v2(2,ii), v2(3,ii), &
+                                                                x1(1, :), x1(2, :), x1(3, :), v1(1, :), v1(2, :), v1(3, :), &
+                                                                renc2(ii), renc1(:), dt, ind_arr, lencounter1(:), &
+                                                                lenc(i)%nenc, lenc(i)%index2, lenc(i)%index1, lenc(i)%lvdotr)
+            end if
+         end do
+         !$omp end parallel do
+         call timer2%stop()
 
-      ! Sweep the intervals for each of the massive bodies along one dimension
-      ! This will build a ragged pair of index lists inside of the lenc data structure
-      call encounter_check_sweep_aabb_all_single_list(n, self%aabb(1)%ind(:), reshape(ibeg(:), [SWEEPDIM, n]), reshape(iend(:), [SWEEPDIM, n]), ind_arr(:), lenc(:))
+         write(*,*) 'double list'
+         call timer1%report(nsubsteps=1, message="timer1           :")
+         call timer2%report(nsubsteps=1, message="timer2           :")
+         ! call timer3%report(nsubsteps=1, message="timer3           :")
+         ! call timer4%report(nsubsteps=1, message="timer4           :")
+         ! call timer5%report(nsubsteps=1, message="timer5           :")
+      end associate
 
-      call encounter_check_collapse_ragged_list(lenc, n, nenc, index1, index2)
+      call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2, lvdotr)
 
-      ! Reorder the pairs and sort the first index in order to remove any duplicates
-      do concurrent(k = 1_I8B:nenc, index2(k) < index1(k))
-         i = index2(k)
-         index2(k) = index1(k)
-         index1(k) = i
-      end do
+      call encounter_check_remove_duplicates(ntot, nenc, index1, index2, lvdotr)
 
       return
-   end subroutine encounter_check_sweep_aabb_single_list
+   end subroutine encounter_check_sweep_aabb_double_list
 
 
-   subroutine encounter_check_sweep_aabb_all_double_list(n1, n2, ext_ind, ibeg, iend, ind_arr, lenc)
+   module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt, nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
-      !! Performs the loop part of the sweep operation. Double list version (e.g. pl-tp or plm-plt)
+      !! Sweeps the sorted bounding box extents and returns the true encounters (combines broad and narrow phases)
+      !! Double list version (e.g. pl-tp or plm-plt)
       implicit none
       ! Arguments
-      integer(I4B),                         intent(in)    :: n1, n2     !! Number of bodies
-      integer(I4B),         dimension(:),   intent(in)    :: ext_ind    !! Sorted index array of extents
-      integer(I8B),         dimension(:,:), intent(in)    :: ibeg, iend !! Beginning and ending index lists in the n-dimensions
-      integer(I4B),         dimension(:),   intent(in)    :: ind_arr    !! index array for mapping body 2 indexes
-      type(encounter_list), dimension(:),   intent(inout) :: lenc       !! Encounter list for the ith body   
+      class(encounter_bounding_box),           intent(inout) :: self       !! Multi-dimensional bounding box structure
+      integer(I4B),                            intent(in)    :: n          !! Number of bodies
+      real(DP),     dimension(:,:),            intent(in)    :: x, v       !! Array of position and velocity vectors 
+      real(DP),     dimension(:),              intent(in)    :: renc       !! Radius of encounter regions of bodies 1
+      real(DP),                                intent(in)    :: dt         !! Step size
+      integer(I8B),                            intent(out)   :: nenc       !! Total number of encounter candidates
+      integer(I4B), dimension(:), allocatable, intent(out)   :: index1     !! List of indices for one body in each encounter candidate pair
+      integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for the other body in each encounter candidate pair
+      logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
-      integer(I4B) :: i, j, ntot
-      integer(I8B) :: ibegx, iendx
-      logical, dimension(n1+n2) :: lencounteri, loverlap
-      integer(I8B), dimension(SWEEPDIM) :: ibegi, iendi
-      logical, dimension(:), allocatable :: lencounterj
+      integer(I4B) :: ii, i
+      integer(I8B) :: k
+      logical, dimension(n) :: loverlap
+      logical, dimension(n) :: lencounteri
       integer(I4B), dimension(:), allocatable :: ext_ind_true
+      type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
+      integer(I4B), dimension(:), allocatable, save :: ind_arr
+      integer(I8B) :: ibegix, iendix
+      integer(I8B), pointer :: ibegx, iendx
+      type(walltimer) :: timer1
+      logical, save :: lfirst = .true.
 
-      ntot = n1 + n2
-      allocate(ext_ind_true, mold=ext_ind)
-      where(ext_ind(:) > ntot)
-         ext_ind_true(:) = ext_ind(:) - ntot
-      elsewhere
-         ext_ind_true(:) = ext_ind(:)
-      endwhere
-
-      loverlap(:) = (iend(1,:) + 1) > (ibeg(1,:) - 1)
-      where(.not.loverlap(:)) lenc(:)%nenc = 0
-      
-      lencounteri(:) = .false.
-      !$omp parallel do default(private) schedule(static)&
-      !$omp shared(ext_ind_true, ibeg, iend, ind_arr, lenc, loverlap) &
-      !$omp firstprivate(ntot, n1, lencounteri) 
-      do i = 1,n1
-         if (loverlap(i)) then
-            ibegi(1) = ibeg(1,i) + 1_I8B
-            iendi(1) = iend(1,i) - 1_I8B
-            ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
-            iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            allocate(lencounterj(1 + iendi(1) - ibegi(1)))
-            lencounterj(:) = ext_ind_true(ibegi(1):iendi(1)) > n1
-            call sweep_list(ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:), lencounterj(:))
-            deallocate(lencounterj)
-            call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), i, lenc(i))
-            lencounteri(ext_ind_true(ibegi(1):iendi(1))) = .false.
-         end if
-      end do
-      !$omp end parallel do
+      if (lfirst) then
+         call timer1%reset()
+         lfirst = .false.
+      end if
 
-      lencounteri(:) = .false.
-      !$omp parallel do default(private) schedule(static)&
-      !$omp shared(ext_ind_true, ibeg, iend, ind_arr, lenc, loverlap) &
-      !$omp firstprivate(n1, n2, lencounteri) 
-      do i = n1+1, n1+n2
-         if (loverlap(i)) then
-            ibegi(1) = ibeg(1,i) + 1_I8B
-            iendi(1) = iend(1,i) - 1_I8B
-            ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
-            iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            allocate(lencounterj(1 + iendi(1) - ibegi(1)))
-            lencounterj(:) = ext_ind_true(ibegi(1):iendi(1)) <= n1
-            call sweep_list(ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:), lencounterj(:))
-            deallocate(lencounterj)
-            call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), i, lenc(i))
-            lencounteri(ext_ind_true(ibegi(1):iendi(1))) = .false.
-         end if
-      end do
-      !$omp end parallel do
+      call util_index_array(ind_arr, n)
 
-      return
+      associate(ext_ind => self%aabb(1)%ind(:), ibegx => self%aabb(1)%ibeg(:), iendx => self%aabb(1)%iend(:))
+         ! Sweep the intervals for each of the massive bodies along one dimension
+         ! This will build a ragged pair of index lists inside of the lenc data structure
+         allocate(ext_ind_true, mold=ext_ind)
+         where(ext_ind(:) > n)
+            ext_ind_true(:) = ext_ind(:) - n
+         elsewhere
+            ext_ind_true(:) = ext_ind(:)
+         endwhere
 
-      contains
+         loverlap(:) = (iendx(:) + 1_I8B) > (ibegx(:) - 1_I8B)
+         where(.not.loverlap(:)) lenc(:)%nenc = 0
 
-   end subroutine encounter_check_sweep_aabb_all_double_list
+         call timer1%start()
+         !$omp parallel do default(private) schedule(static)&
+         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x, v, renc) &
+         !$omp firstprivate(n, dt) 
+         do i = 1, n
+            if (loverlap(i)) then
+               ibegix = ibegx(i) + 1_I8B
+               iendix = iendx(i) - 1_I8B
 
+               lencounteri(:) = .false.
+               lencounteri(ext_ind_true(ibegix:iendix)) = .true.
+               call encounter_check_all_sweep_one(i, n, x(1,i), x(2,i), x(3,i), v(1,i), v(2,i), v(3,i), &
+                                                        x(1,:), x(2,:), x(3,:), v(1,:), v(2,:), v(3,:), &
+                                                        renc(i), renc(:), dt, ind_arr, lencounteri(:), &
+                                                        lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
+             end if
+         end do
+         !$omp end parallel do
+         call timer1%stop()
 
-   subroutine encounter_check_sweep_aabb_all_single_list(n, ext_ind, ibeg, iend, ind_arr, lenc)
-      !! author: David A. Minton
-      !!
-      !! Performs the loop part of the sweep operation. Single list version (e.g. pl-pl)
-      implicit none
-      ! Arguments
-      integer(I4B),                         intent(in)    :: n          !! Number of bodies
-      integer(I4B),         dimension(:),   intent(in)    :: ext_ind    !! Sorted index array of extents
-      integer(I8B),         dimension(:,:), intent(in)    :: ibeg, iend !! Beginning and ending index lists in the n-dimension
-      integer(I4B),         dimension(:),   intent(in)    :: ind_arr    !! index array for mapping body 2 indexes
-      type(encounter_list), dimension(:),   intent(inout) :: lenc       !! Encounter list for the ith body   
-      ! Internals
-      integer(I4B) :: i
-      logical, dimension(n) :: lencounteri, loverlap
-      logical, dimension(:), allocatable :: lencounterj
-      integer(I8B), dimension(SWEEPDIM) :: ibegi, iendi
-      integer(I4B), dimension(:), allocatable :: ext_ind_true
+         write(*,*) 'single list'
+         call timer1%report(nsubsteps=1, message="timer1           :")
+      end associate
 
-      allocate(ext_ind_true, mold=ext_ind)
-      where(ext_ind(:) > n)
-         ext_ind_true(:) = ext_ind(:) - n
-      elsewhere
-         ext_ind_true(:) = ext_ind(:)
-      endwhere
+      call encounter_check_collapse_ragged_list(lenc, n, nenc, index1, index2, lvdotr)
 
-      loverlap(:) = (iend(1,:) + 1_I8B) > (ibeg(1,:) - 1_I8B)
-      where(.not.loverlap(:)) lenc(:)%nenc = 0
-      lencounteri(:) = .false.
-      !$omp parallel do default(private) schedule(static)&
-      !$omp shared(ext_ind_true, ibeg, iend, ind_arr, lenc, loverlap) &
-      !$omp firstprivate(n, lencounteri)
-      do i = 1, n
-         if (loverlap(i)) then
-            ibegi(1) = ibeg(1,i) + 1_I8B
-            iendi(1) = iend(1,i) - 1_I8B
-            ibegi(2:SWEEPDIM) = ibeg(2:SWEEPDIM,i) 
-            iendi(2:SWEEPDIM) = iend(2:SWEEPDIM,i) 
-            allocate(lencounterj(1 + iendi(1) - ibegi(1)))
-            lencounterj(:) = .true.
-            call sweep_list(ext_ind_true(:), ibegi(:), iendi(:), ibeg(:,:), iend(:,:), lencounteri(:), lencounterj(:))
-            deallocate(lencounterj)
-            call encounter_check_make_ragged_list(lencounteri(:), ind_arr(:), i, lenc(i))
-            lencounteri(ext_ind_true(ibegi(1):iendi(1))) = .false.
-         end if
-      end do
-      !$omp end parallel do
+      call encounter_check_remove_duplicates(n, nenc, index1, index2, lvdotr)
 
       return
-   end subroutine encounter_check_sweep_aabb_all_single_list
-
-
-   pure subroutine sweep_list(ext_ind, ibegi, iendi, ibeg, iend, lencounteri, lencounterj)
-      !! author: David A. Minton
-      !!
-      !! Performs a sweep operation on a single body. Encounters from the same lists not allowed (e.g. pl-tp encounters only)
-      implicit none
-      ! Arguments
-      integer(I4B), dimension(:),   intent(in)    :: ext_ind      !! Sorted index array of extents
-      integer(I8B), dimension(:),   intent(in)    :: ibegi, iendi !! The beginning and ending indices of the ith bounding box in the n-dimensions
-      integer(I8B), dimension(:,:), intent(in)    :: ibeg, iend   !! Beginning and ending index lists in the n-dimensions
-      logical, dimension(:),        intent(out)   :: lencounteri    !! Encounter list for the ith body
-      logical, dimension(:),        intent(inout) :: lencounterj
-      ! Internals
-      integer(I8B) :: j, jbox, dim, jlo, jhi
-      integer(I4B), dimension(ibegi(1):iendi(1)) :: box
-      integer(I8B), dimension(ibegi(1):iendi(1)) :: iendy, ibegy
-      integer(I8B), dimension(ibegi(1):iendi(1)) :: iendz, ibegz
-
-      jlo = ibegi(1)
-      jhi = iendi(1)
+   end subroutine encounter_check_sweep_aabb_single_list
 
-      box(jlo:jhi) = ext_ind(jlo:jhi)
-      
-      ibegy(jlo:jhi) = ibeg(2,box(jlo:jhi))
-      iendy(jlo:jhi) = iend(2,box(jlo:jhi))
-      ibegz(jlo:jhi) = ibeg(3,box(jlo:jhi))
-      iendz(jlo:jhi) = iend(3,box(jlo:jhi))
-      
-      lencounterj(:) = lencounterj(:) .and. (iendy(jlo:jhi) > ibegi(2)) &
-                                      .and. (ibegy(jlo:jhi) < iendi(2)) &
-                                      .and. (iendz(jlo:jhi) > ibegi(3)) &
-                                      .and. (ibegz(jlo:jhi) < iendi(3))
-     
-      do concurrent (j = jlo:jhi, lencounterj(j - jlo + 1))
-         lencounteri(box(j)) = .true. 
-      end do
-      
-      return
-   end subroutine sweep_list
 end submodule s_encounter_check
diff --git a/src/modules/encounter_classes.f90 b/src/modules/encounter_classes.f90
index bf85eb626..5c4e963d6 100644
--- a/src/modules/encounter_classes.f90
+++ b/src/modules/encounter_classes.f90
@@ -68,7 +68,7 @@ module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc
          logical,      dimension(:),   intent(out) :: lvdotr     !! Logical array indicating which pairs are approaching
       end subroutine encounter_check_all
 
-      module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, lvdotr, index1, index2, nenc)
+      module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, nenc, index1, index2, lvdotr)
          use swiftest_classes, only: swiftest_parameters
          implicit none
          class(swiftest_parameters),              intent(inout) :: param  !! Current Swiftest run configuration parameter5s
@@ -83,7 +83,7 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, lvdotr, i
          integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       end subroutine encounter_check_all_plpl
 
-      module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, lvdotr, index1, index2, nenc)
+      module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr)
          use swiftest_classes, only: swiftest_parameters
          implicit none
          class(swiftest_parameters),              intent(inout) :: param  !! Current Swiftest run configuration parameter5s
@@ -96,13 +96,13 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          real(DP),     dimension(:),              intent(in)    :: rencm  !! Critical radii of fully interacting massive bodies that defines an encounter
          real(DP),     dimension(:),              intent(in)    :: renct  !! Critical radii of partially interacting massive bodies that defines an encounter
          real(DP),                                intent(in)    :: dt     !! Step size
-         logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
+         integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
          integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
          integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-         integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
+         logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       end subroutine encounter_check_all_plplm
 
-      module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp, renc, dt, lvdotr, index1, index2, nenc)
+      module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr)
          use swiftest_classes, only: swiftest_parameters
          implicit none
          class(swiftest_parameters),              intent(inout) :: param  !! Current Swiftest run configuration parameter5s
@@ -114,10 +114,10 @@ module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp,
          real(DP),     dimension(:,:),            intent(in)    :: vtp    !! Velocity vectors of massive bodies
          real(DP),     dimension(:),              intent(in)    :: renc   !! Critical radii of massive bodies that defines an encounter
          real(DP),                                intent(in)    :: dt     !! Step size
-         logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
+         integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
          integer(I4B), dimension(:), allocatable, intent(out)   :: index1 !! List of indices for body 1 in each encounter
          integer(I4B), dimension(:), allocatable, intent(out)   :: index2 !! List of indices for body 2 in each encounter
-         integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
+         logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       end subroutine encounter_check_all_pltp
 
       module pure subroutine encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc, dt, lencounter, lvdotr)
@@ -148,23 +148,33 @@ module pure subroutine encounter_check_sort_aabb_1D(self, n, extent_arr)
          real(DP), dimension(:),           intent(in)    :: extent_arr !! Array of extents of size 2*n
       end subroutine encounter_check_sort_aabb_1D
 
-      module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, nenc, index1, index2)
+      module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x2, v2, renc1, renc2, dt, nenc, index1, index2, lvdotr)
          implicit none
-         class(encounter_bounding_box),           intent(inout) :: self     !! Multi-dimensional bounding box structure
-         integer(I4B),                            intent(in)    :: n1       !! Number of bodies 1
-         integer(I4B),                            intent(in)    :: n2       !! Number of bodies 2
-         integer(I8B),                            intent(out)   :: nenc     !! Total number of encounter candidates
-         integer(I4B), dimension(:), allocatable, intent(out)   :: index1   !! List of indices for body 1 in each encounter candidate pair
-         integer(I4B), dimension(:), allocatable, intent(out)   :: index2   !! List of indices for body 2 in each encounter candidate pair
+         class(encounter_bounding_box),           intent(inout) :: self       !! Multi-dimensional bounding box structure
+         integer(I4B),                            intent(in)    :: n1         !! Number of bodies 1
+         integer(I4B),                            intent(in)    :: n2         !! Number of bodies 2
+         real(DP),     dimension(:,:),            intent(in)    :: x1, v1     !! Array of indices of bodies 1
+         real(DP),     dimension(:,:),            intent(in)    :: x2, v2     !! Array of indices of bodies 2
+         real(DP),     dimension(:),              intent(in)    :: renc1      !! Radius of encounter regions of bodies 1
+         real(DP),     dimension(:),              intent(in)    :: renc2      !! Radius of encounter regions of bodies 2
+         real(DP),                                intent(in)    :: dt         !! Step size
+         integer(I8B),                            intent(out)   :: nenc       !! Total number of encounter candidates
+         integer(I4B), dimension(:), allocatable, intent(out)   :: index1     !! List of indices for body 1 in each encounter candidate pair
+         integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for body 2 in each encounter candidate pair
+         logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       end subroutine encounter_check_sweep_aabb_double_list
 
-      module subroutine encounter_check_sweep_aabb_single_list(self, n, nenc, index1, index2)
+      module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt, nenc, index1, index2, lvdotr)
          implicit none
-         class(encounter_bounding_box),           intent(inout) :: self    !! Multi-dimensional bounding box structure
-         integer(I4B),                            intent(in)    :: n       !! Number of bodies 1
-         integer(I8B),                            intent(out)   :: nenc    !! Total number of encounter candidates
-         integer(I4B), dimension(:), allocatable, intent(out)   :: index1  !! List of indices for body 1 in each encounter candidate pair
-         integer(I4B), dimension(:), allocatable, intent(out)   :: index2  !! List of indices for body 2 in each encounter candidate pair
+         class(encounter_bounding_box),           intent(inout) :: self       !! Multi-dimensional bounding box structure
+         integer(I4B),                            intent(in)    :: n          !! Number of bodies
+         real(DP),     dimension(:,:),            intent(in)    :: x, v       !! Array of position and velocity vectors 
+         real(DP),     dimension(:),              intent(in)    :: renc       !! Radius of encounter regions of bodies 1
+         real(DP),                                intent(in)    :: dt         !! Step size
+         integer(I8B),                            intent(out)   :: nenc       !! Total number of encounter candidates
+         integer(I4B), dimension(:), allocatable, intent(out)   :: index1     !! List of indices for one body in each encounter candidate pair
+         integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for the other body in each encounter candidate pair
+         logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       end subroutine encounter_check_sweep_aabb_single_list
 
       module subroutine encounter_io_write_frame(iu, t, id1, id2, Gmass1, Gmass2, radius1, radius2, xh1, xh2, vh1, vh2)
diff --git a/src/rmvs/rmvs_encounter_check.f90 b/src/rmvs/rmvs_encounter_check.f90
index c63e7f2de..f698ea4f0 100644
--- a/src/rmvs/rmvs_encounter_check.f90
+++ b/src/rmvs/rmvs_encounter_check.f90
@@ -36,7 +36,7 @@ module function rmvs_encounter_check_tp(self, param, system, dt) result(lencount
       class is (rmvs_pl)
          associate(tp => self, ntp => self%nbody, npl => pl%nbody)
             tp%plencP(1:ntp) = 0
-            call encounter_check_all_pltp(param, npl, ntp, pl%xbeg, pl%vbeg, tp%xh, tp%vh, pl%renc, dt, lvdotr, index1, index2, nenc)
+            call encounter_check_all_pltp(param, npl, ntp, pl%xbeg, pl%vbeg, tp%xh, tp%vh, pl%renc, dt, nenc, index1, index2, lvdotr)
 
             lencounter = (nenc > 0_I8B)
             if (lencounter) then
diff --git a/src/symba/symba_encounter_check.f90 b/src/symba/symba_encounter_check.f90
index 241657b67..4f8495440 100644
--- a/src/symba/symba_encounter_check.f90
+++ b/src/symba/symba_encounter_check.f90
@@ -38,9 +38,9 @@ module function symba_encounter_check_pl(self, param, system, dt, irec) result(l
          call pl%set_renc(irec)
 
          if (nplt == 0) then
-            call encounter_check_all_plpl(param, npl, pl%xh, pl%vh, pl%renc, dt, lvdotr, index1, index2, nenc)
+            call encounter_check_all_plpl(param, npl, pl%xh, pl%vh, pl%renc, dt, nenc, index1, index2, lvdotr)
          else
-            call encounter_check_all_plplm(param, nplm, nplt, pl%xh(:,1:nplm), pl%vh(:,1:nplm), pl%xh(:,nplm+1:npl), pl%vh(:,nplm+1:npl), pl%renc(1:nplm), pl%renc(nplm+1:npl), dt, lvdotr, index1, index2, nenc)
+            call encounter_check_all_plplm(param, nplm, nplt, pl%xh(:,1:nplm), pl%vh(:,1:nplm), pl%xh(:,nplm+1:npl), pl%vh(:,nplm+1:npl), pl%renc(1:nplm), pl%renc(nplm+1:npl), dt, nenc, index1, index2, lvdotr)
          end if
          
          lany_encounter = nenc > 0_I8B
@@ -209,7 +209,7 @@ module function symba_encounter_check_tp(self, param, system, dt, irec) result(l
 
       associate(tp => self, ntp => self%nbody, pl => system%pl, npl => system%pl%nbody)
          call pl%set_renc(irec)
-         call encounter_check_all_pltp(param, npl, ntp, pl%xh, pl%vh, tp%xh, tp%vh, pl%renc, dt, lvdotr, index1, index2, nenc) 
+         call encounter_check_all_pltp(param, npl, ntp, pl%xh, pl%vh, tp%xh, tp%vh, pl%renc, dt, nenc, index1, index2, lvdotr) 
    
          lany_encounter = nenc > 0
          if (lany_encounter) then 

From a599b9ff6c478b404a54efb549ec60bf4119ce5e Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Tue, 23 Nov 2021 11:30:42 -0500
Subject: [PATCH 15/24] Fixed index ordering in single list. test case with new
 sort & sweep now matches triangular

---
 src/encounter/encounter_check.f90 | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 360c01113..a669855ca 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -924,7 +924,7 @@ module pure subroutine encounter_check_sort_aabb_1D(self, n, extent_arr)
 
       call util_sort(extent_arr, self%ind)
 
-      do concurrent(k = 1_I8B:2_I8B*n)
+      do concurrent(k = 1_I8B:2_I8B * n)
          i = self%ind(k)
          if (i <= n) then
             self%ibeg(i) = k
@@ -1072,7 +1072,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
       integer(I4B) :: ii, i
-      integer(I8B) :: k
+      integer(I8B) :: k, itmp
       logical, dimension(n) :: loverlap
       logical, dimension(n) :: lencounteri
       integer(I4B), dimension(:), allocatable :: ext_ind_true
@@ -1129,6 +1129,13 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
 
       call encounter_check_collapse_ragged_list(lenc, n, nenc, index1, index2, lvdotr)
 
+      ! By convention, we always assume that index1 < index2, and so we must swap any that are out of order
+      do concurrent(k = 1_I8B:nenc, index1(k) > index2(k))
+         itmp = index1(k)
+         index1(k) = index2(k)
+         index2(k) = itmp
+      end do
+
       call encounter_check_remove_duplicates(n, nenc, index1, index2, lvdotr)
 
       return

From 098748428ef19233b21952440b647c0d24e1fa52 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Tue, 23 Nov 2021 15:46:45 -0500
Subject: [PATCH 16/24] Shortened and/or split lines to fit gfortran's default
 line width

---
 src/discard/discard.f90             | 30 ++++++---
 src/encounter/encounter_check.f90   | 94 ++++++++++++++++++-----------
 src/encounter/encounter_io.f90      | 10 +--
 src/fraggle/fraggle_generate.f90    | 24 +++++---
 src/fraggle/fraggle_regime.f90      | 11 ++--
 src/fraggle/fraggle_set.f90         |  3 +-
 src/fraggle/fraggle_util.f90        |  6 +-
 src/gr/gr.f90                       |  3 +-
 src/io/io.f90                       | 29 +++++----
 src/main/swiftest_driver.f90        |  6 +-
 src/modules/encounter_classes.f90   |  6 +-
 src/modules/swiftest_classes.f90    |  3 +-
 src/netcdf/netcdf.f90               |  7 ++-
 src/rmvs/rmvs_discard.f90           |  7 ++-
 src/rmvs/rmvs_encounter_check.f90   |  3 +-
 src/rmvs/rmvs_step.f90              |  9 ++-
 src/setup/setup.f90                 |  9 ++-
 src/symba/symba_collision.f90       | 51 +++++++++++-----
 src/symba/symba_discard.f90         | 45 +++++++++-----
 src/symba/symba_encounter_check.f90 |  6 +-
 src/symba/symba_io.f90              | 21 ++++---
 src/symba/symba_setup.f90           |  6 +-
 src/symba/symba_step.f90            | 28 ++++++---
 src/symba/symba_util.f90            |  6 +-
 src/util/util_peri.f90              |  6 +-
 src/util/util_set.f90               |  3 +-
 src/walltime/walltime.f90           |  9 ++-
 27 files changed, 282 insertions(+), 159 deletions(-)

diff --git a/src/discard/discard.f90 b/src/discard/discard.f90
index ad5b73426..b7527c330 100644
--- a/src/discard/discard.f90
+++ b/src/discard/discard.f90
@@ -128,18 +128,22 @@ subroutine discard_cb_tp(tp, system, param)
                   tp%status(i) = DISCARDED_RMAX
                   write(idstr, *) tp%id(i)
                   write(timestr, *) param%t
-                  write(*, *) "Particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" // " too far from the central body at t = " // trim(adjustl(timestr))
+                  write(*, *) "Particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" // &
+                              " too far from the central body at t = " // trim(adjustl(timestr))
                   tp%ldiscard(i) = .true.
                   tp%lmask(i) = .false.
-                  call tp%info(i)%set_value(status="DISCARDED_RMAX", discard_time=param%t, discard_xh=tp%xh(:,i), discard_vh=tp%vh(:,i))
+                  call tp%info(i)%set_value(status="DISCARDED_RMAX", discard_time=param%t, discard_xh=tp%xh(:,i), &
+                                            discard_vh=tp%vh(:,i))
                else if ((param%rmin >= 0.0_DP) .and. (rh2 < rmin2)) then
                   tp%status(i) = DISCARDED_RMIN
                   write(idstr, *) tp%id(i)
                   write(timestr, *) param%t
-                  write(*, *) "Particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" //  " too close to the central body at t = " // trim(adjustl(timestr))
+                  write(*, *) "Particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" // &
+                              " too close to the central body at t = " // trim(adjustl(timestr))
                   tp%ldiscard(i) = .true.
                   tp%lmask(i) = .false.
-                  call tp%info(i)%set_value(status="DISCARDED_RMIN", discard_time=param%t, discard_xh=tp%xh(:,i), discard_vh=tp%vh(:,i), discard_body_id=cb%id)
+                  call tp%info(i)%set_value(status="DISCARDED_RMIN", discard_time=param%t, discard_xh=tp%xh(:,i), &
+                                            discard_vh=tp%vh(:,i), discard_body_id=cb%id)
                else if (param%rmaxu >= 0.0_DP) then
                   rb2 = dot_product(tp%xb(:, i),  tp%xb(:, i))
                   vb2 = dot_product(tp%vb(:, i), tp%vb(:, i))
@@ -148,10 +152,12 @@ subroutine discard_cb_tp(tp, system, param)
                      tp%status(i) = DISCARDED_RMAXU
                      write(idstr, *) tp%id(i)
                      write(timestr, *) param%t
-                     write(*, *) "Particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" //  " is unbound and too far from barycenter at t = " // trim(adjustl(timestr))
+                     write(*, *) "Particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" // &
+                                 " is unbound and too far from barycenter at t = " // trim(adjustl(timestr))
                      tp%ldiscard(i) = .true.
                      tp%lmask(i) = .false.
-                     call tp%info(i)%set_value(status="DISCARDED_RMAXU", discard_time=param%t, discard_xh=tp%xh(:,i), discard_vh=tp%vh(:,i))
+                     call tp%info(i)%set_value(status="DISCARDED_RMAXU", discard_time=param%t, discard_xh=tp%xh(:,i), &
+                                               discard_vh=tp%vh(:,i))
                   end if
                end if
             end if
@@ -199,9 +205,11 @@ subroutine discard_peri_tp(tp, system, param)
                         tp%status(i) = DISCARDED_PERI
                         write(idstr, *) tp%id(i)
                         write(timestr, *) param%t
-                        write(*, *) "Particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" // " perihelion distance too small at t = " // trim(adjustl(timestr))
+                        write(*, *) "Particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" // &
+                                    " perihelion distance too small at t = " // trim(adjustl(timestr))
                         tp%ldiscard(i) = .true.
-                        call tp%info(i)%set_value(status="DISCARDED_PERI", discard_time=param%t, discard_xh=tp%xh(:,i), discard_vh=tp%vh(:,i), discard_body_id=pl%id(j))
+                        call tp%info(i)%set_value(status="DISCARDED_PERI", discard_time=param%t, discard_xh=tp%xh(:,i), &
+                                                  discard_vh=tp%vh(:,i), discard_body_id=pl%id(j))
                      end if
                   end if
                end if
@@ -247,10 +255,12 @@ subroutine discard_pl_tp(tp, system, param)
                      write(idstrj, *) pl%id(j)
                      write(timestr, *) param%t
                      write(*, *) "Test particle " // trim(adjustl(tp%info(i)%name)) // " ("  // trim(adjustl(idstri)) // ")" &
-                                                  // "  too close to massive body " // trim(adjustl(pl%info(i)%name)) // " ("  // trim(adjustl(idstrj)) &
+                                                  // "  too close to massive body " // trim(adjustl(pl%info(i)%name)) // &
+                                                  " ("  // trim(adjustl(idstrj)) &
                                                   // " at t = " // trim(adjustl(timestr))
                      tp%ldiscard(i) = .true.
-                     call tp%info(i)%set_value(status="DISCARDED_PLR", discard_time=param%t, discard_xh=tp%xh(:,i), discard_vh=tp%vh(:,i), discard_body_id=pl%id(j))
+                     call tp%info(i)%set_value(status="DISCARDED_PLR", discard_time=param%t, discard_xh=tp%xh(:,i), &
+                                               discard_vh=tp%vh(:,i), discard_body_id=pl%id(j))
                      exit
                   end if
                end do
diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index a669855ca..ccd3d23ce 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -2,7 +2,8 @@
    use swiftest
 contains
 
-   module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc1, renc2, dt, lencounter, lvdotr)
+   module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc1, renc2, dt, &
+                                         lencounter, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between n pairs of bodies. 
@@ -46,7 +47,8 @@ module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc
    end subroutine encounter_check_all
 
 
-   module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, nenc, index1, index2, lvdotr)
+   module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, &
+                                              nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies. Choose between the standard triangular or the Sort & Sweep method based on user inputs
@@ -68,11 +70,14 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, nenc, ind
       logical, save :: lfirst = .true.
       logical, save :: skipit = .false. ! This will be used to ensure that the sort & sweep subroutine gets called at least once before timing it so that the extent array is nearly sorted when it is timed
       integer(I8B) :: nplpl = 0_I8B
+      integer(I8B) :: k
+      type(walltimer), save :: timer
 
       if (param%ladaptive_encounters_plpl .and. (.not. skipit)) then
          nplpl = (npl * (npl - 1) / 2) 
          if (nplpl > 0) then
             if (lfirst) then  
+               call timer%reset()
                write(itimer%loopname, *) "encounter_check_all_plpl"
                write(itimer%looptype, *) "ENCOUNTER_PLPL"
                lfirst = .false.
@@ -84,12 +89,15 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, nenc, ind
             param%lencounter_sas_plpl = .false.
          end if
       end if
-
+      
+      call timer%start()
       if (param%lencounter_sas_plpl) then
          call encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, nenc, index1, index2, lvdotr) 
       else
          call encounter_check_all_triangular_plpl(npl, x, v, renc, dt, nenc, index1, index2, lvdotr) 
       end if
+      call timer%stop()
+      call timer%report(nsubsteps=1, message="plpl Encounter check  :")
 
       if (skipit) then
          skipit = .false.
@@ -102,11 +110,19 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, nenc, ind
          end if
       end if
 
+      ! TEMP FOR TESTING
+      open(unit=22,file="enclist.csv", status="replace")
+      do k = 1_I8B, nenc
+         write(22,*) index1(k), index2(k)
+      end do
+      close(22)
+
       return
    end subroutine encounter_check_all_plpl
 
 
-   module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr)
+   module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
+                                               nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between fully interacting massive bodies partially interacting massive bodies. Choose between the standard triangular or the Sort & Sweep method based on user inputs
@@ -172,12 +188,14 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, nenc, index1, index2, lvdotr)
 
       if (param%lencounter_sas_plpl) then
-         call encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr)
+         call encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
+                                                       plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr)
       else
-         call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr) 
+         call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
+                                                       plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr) 
       end if
       call timer%stop()
-      call timer%report(nsubsteps=1, message="Encounter check  :")
+      call timer%report(nsubsteps=1, message="plplm Encounter check  :")
 
       if (skipit) then
          skipit = .false.
@@ -222,7 +240,8 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
    end subroutine encounter_check_all_plplm
 
 
-   module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr)
+   module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp, renc, dt, &
+                                              nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. Choose between the standard triangular or the Sort & Sweep method based on user inputs
@@ -308,7 +327,7 @@ subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, nenc, in
       type(encounter_bounding_box), save :: boundingbox
       logical, dimension(:), allocatable :: lencounter
       integer(I2B), dimension(npl) :: vshift_min, vshift_max
-      type(walltimer) :: timer 
+      type(walltimer), save :: timer 
 
       if (npl == 0) return
 
@@ -341,7 +360,8 @@ subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, nenc, in
    end subroutine encounter_check_all_sort_and_sweep_plpl
 
 
-   subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr)
+   subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
+                                                       nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. 
@@ -415,7 +435,8 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
    end subroutine encounter_check_all_sort_and_sweep_plplm
 
 
-   subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr)
+   subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, &
+                                                      nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. 
@@ -488,7 +509,8 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
    end subroutine encounter_check_all_sort_and_sweep_pltp
 
 
-   pure subroutine encounter_check_all_sweep_one(i, n, xi, yi, zi, vxi, vyi, vzi, x, y, z, vx, vy, vz, renci, renc, dt, ind_arr, lgood, nenci, index1, index2, lvdotr)
+   pure subroutine encounter_check_all_sweep_one(i, n, xi, yi, zi, vxi, vyi, vzi, x, y, z, vx, vy, vz, renci, renc, dt, &
+                                                 ind_arr, lgood, nenci, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between the ith body and all other bodies.
@@ -539,7 +561,8 @@ pure subroutine encounter_check_all_sweep_one(i, n, xi, yi, zi, vxi, vyi, vzi, x
    end subroutine encounter_check_all_sweep_one
 
 
-   pure subroutine encounter_check_all_triangular_one(i, n, xi, yi, zi, vxi, vyi, vzi, x, y, z, vx, vy, vz, renci, renc, dt, ind_arr, lenci)
+   pure subroutine encounter_check_all_triangular_one(i, n, xi, yi, zi, vxi, vyi, vzi, x, y, z, vx, vy, vz, renci, renc, &
+                                                      dt, ind_arr, lenci)
       !! author: David A. Minton
       !!
       !! Check for encounters between the ith body and all other bodies.
@@ -607,7 +630,7 @@ subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, nenc, index1
       logical, dimension(npl) :: lencounteri, lvdotri
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       type(encounter_list), dimension(npl) :: lenc
-      type(walltimer) :: timer 
+      type(walltimer), save :: timer 
 
       call util_index_array(ind_arr, npl) 
 
@@ -630,7 +653,8 @@ subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, nenc, index1
    end subroutine encounter_check_all_triangular_plpl
 
 
-   subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr)
+   subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
+                                                   nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. Split off from the main subroutine for performance
@@ -655,7 +679,7 @@ subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vp
       logical, dimension(nplt) :: lencounteri, lvdotri
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       type(encounter_list), dimension(nplm) :: lenc
-      type(walltimer) :: timer 
+      type(walltimer), save :: timer 
 
       call util_index_array(ind_arr, nplt)
 
@@ -678,7 +702,8 @@ subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vp
    end subroutine encounter_check_all_triangular_plplm
 
 
-   subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, nenc, index1, index2, lvdotr)
+   subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, &
+                                                  nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Check for encounters between massive bodies and test particles. Split off from the main subroutine for performance
@@ -937,7 +962,8 @@ module pure subroutine encounter_check_sort_aabb_1D(self, n, extent_arr)
    end subroutine encounter_check_sort_aabb_1D 
 
 
-   module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x2, v2, renc1, renc2, dt, nenc, index1, index2, lvdotr)
+   module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x2, v2, renc1, renc2, dt, &
+                                                            nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
       !! Sweeps the sorted bounding box extents and returns the true encounters (combines broad and narrow phases)
@@ -967,8 +993,7 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
       type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I8B) :: ibegix, iendix
-      integer(I8B), pointer :: ibegx, iendx
-      type(walltimer) :: timer1, timer2, timer3, timer4, timer5
+      type(walltimer), save :: timer1, timer2, timer3, timer4, timer5
       logical, save :: lfirst = .true.
 
       if (lfirst) then
@@ -983,7 +1008,7 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
 
-      associate(ext_ind => self%aabb(1)%ind(:), ibegx => self%aabb(1)%ibeg(:), iendx => self%aabb(1)%iend(:))
+      associate(ext_ind => self%aabb(1)%ind(:))
          ! Sweep the intervals for each of the massive bodies along one dimension
          ! This will build a ragged pair of index lists inside of the lenc data structure
          allocate(ext_ind_true, mold=ext_ind)
@@ -995,17 +1020,17 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
          endwhere
          llist1(:) = ext_ind_true(:) <= n1
 
-         loverlap(:) = (iendx(:) + 1_I8B) > (ibegx(:) - 1_I8B)
+         loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) > (self%aabb(1)%iend(:) - 1_I8B)
          where(.not.loverlap(:)) lenc(:)%nenc = 0
 
          call timer1%start()
          !$omp parallel do default(private) schedule(static)&
-         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
+         !$omp shared(self, ext_ind_true, ind_arr, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
          !$omp firstprivate(ntot, n1, n2, dt) 
          do i = 1, n1
             if (loverlap(i)) then
-               ibegix = ibegx(i) + 1_I8B
-               iendix = iendx(i) - 1_I8B
+               ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
+               iendix =  self%aabb(1)%iend(i) - 1_I8B
 
                lencounter2(:) = .false.
                where(.not.llist1(ibegix:iendix)) lencounter2(ext_ind_true(ibegix:iendix) - n1) = .true.
@@ -1020,12 +1045,12 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
 
          call timer2%start()
          !$omp parallel do default(private) schedule(static)&
-         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
+         !$omp shared(self, ext_ind_true, ind_arr, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
          !$omp firstprivate(ntot, n1, dt) 
          do i = n1+1, ntot
             if (loverlap(i)) then
-               ibegix = ibegx(i) + 1_I8B
-               iendix = iendx(i) - 1_I8B
+               ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
+               iendix =  self%aabb(1)%iend(i) - 1_I8B
                lencounter1(:) = .false.
                where(llist1(ibegix:iendix)) lencounter1(ext_ind_true(ibegix:iendix)) = .true.
                ii = i - n1
@@ -1079,8 +1104,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
       type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I8B) :: ibegix, iendix
-      integer(I8B), pointer :: ibegx, iendx
-      type(walltimer) :: timer1
+      type(walltimer), save :: timer1
       logical, save :: lfirst = .true.
 
       if (lfirst) then
@@ -1090,7 +1114,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
 
       call util_index_array(ind_arr, n)
 
-      associate(ext_ind => self%aabb(1)%ind(:), ibegx => self%aabb(1)%ibeg(:), iendx => self%aabb(1)%iend(:))
+      associate(ext_ind => self%aabb(1)%ind(:))
          ! Sweep the intervals for each of the massive bodies along one dimension
          ! This will build a ragged pair of index lists inside of the lenc data structure
          allocate(ext_ind_true, mold=ext_ind)
@@ -1100,17 +1124,17 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
             ext_ind_true(:) = ext_ind(:)
          endwhere
 
-         loverlap(:) = (iendx(:) + 1_I8B) > (ibegx(:) - 1_I8B)
+         loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) > (self%aabb(1)%iend(:) - 1_I8B)
          where(.not.loverlap(:)) lenc(:)%nenc = 0
 
          call timer1%start()
          !$omp parallel do default(private) schedule(static)&
-         !$omp shared(ext_ind_true, ind_arr, ibegx, iendx, lenc, loverlap, x, v, renc) &
+         !$omp shared(self, ext_ind_true, ind_arr, lenc, loverlap, x, v, renc) &
          !$omp firstprivate(n, dt) 
          do i = 1, n
             if (loverlap(i)) then
-               ibegix = ibegx(i) + 1_I8B
-               iendix = iendx(i) - 1_I8B
+               ibegix = self%aabb(1)%ibeg(i) + 1_I8B
+               iendix = self%aabb(1)%iend(i) - 1_I8B
 
                lencounteri(:) = .false.
                lencounteri(ext_ind_true(ibegix:iendix)) = .true.
diff --git a/src/encounter/encounter_io.f90 b/src/encounter/encounter_io.f90
index 60fdf5304..d7785a71a 100644
--- a/src/encounter/encounter_io.f90
+++ b/src/encounter/encounter_io.f90
@@ -22,9 +22,9 @@ module subroutine encounter_io_write_frame(iu, t, id1, id2, Gmass1, Gmass2, radi
       ! Internals
       character(len=STRMAX)   :: errmsg
 
-      write(iu, err = 667, iomsg = errmsg) t
-      write(iu, err = 667, iomsg = errmsg) id1, xh1(1), xh1(2), xh1(3), vh1(1), vh1(2), Gmass1, radius1
-      write(iu, err = 667, iomsg = errmsg) id2, xh2(1), xh2(2), xh2(3), vh2(1), vh2(2), Gmass2, radius2
+      write(iu, err=667, iomsg=errmsg) t
+      write(iu, err=667, iomsg=errmsg) id1, xh1(1), xh1(2), xh1(3), vh1(1), vh1(2), Gmass1, radius1
+      write(iu, err=667, iomsg=errmsg) id2, xh2(1), xh2(2), xh2(3), vh2(1), vh2(2), Gmass2, radius2
 
       return
       667 continue
@@ -46,10 +46,10 @@ module subroutine encounter_io_write_list(self, pl, encbody, param)
 
       if (param%enc_out == "" .or. self%nenc == 0) return
 
-      open(unit = LUN, file = param%enc_out, status = 'OLD', position = 'APPEND', form = 'UNFORMATTED', iostat = ierr, iomsg = errmsg)
+      open(unit=LUN, file=param%enc_out, status='OLD', position='APPEND', form='UNFORMATTED', iostat=ierr, iomsg=errmsg)
       if (ierr /= 0) then
          if (lfirst) then
-            open(unit = LUN, file = param%enc_out, status = 'NEW', form = 'UNFORMATTED', err = 667, iomsg = errmsg)
+            open(unit=LUN, file=param%enc_out, status='NEW', form='UNFORMATTED', err=667, iomsg=errmsg)
          else
             goto 667
          end if
diff --git a/src/fraggle/fraggle_generate.f90 b/src/fraggle/fraggle_generate.f90
index 0b0126702..2b443bebe 100644
--- a/src/fraggle/fraggle_generate.f90
+++ b/src/fraggle/fraggle_generate.f90
@@ -110,14 +110,16 @@ module subroutine fraggle_generate_fragments(self, colliders, system, param, lfa
             lfailure = ((abs(dEtot + frag%Qloss) > FRAGGLE_ETOL) .or. (dEtot > 0.0_DP)) 
             if (lfailure) then
                write(message, *) dEtot, abs(dEtot + frag%Qloss) / FRAGGLE_ETOL
-               call io_log_one_message(FRAGGLE_LOG_OUT, "Fraggle failed due to high energy error: " // trim(adjustl(message)))
+               call io_log_one_message(FRAGGLE_LOG_OUT, "Fraggle failed due to high energy error: " // &
+                                                        trim(adjustl(message)))
                cycle
             end if
 
             lfailure = ((abs(dLmag) / (.mag.frag%Ltot_before)) > FRAGGLE_LTOL) 
             if (lfailure) then
                write(message,*) dLmag / (.mag.frag%Ltot_before(:))
-               call io_log_one_message(FRAGGLE_LOG_OUT, "Fraggle failed due to high angular momentum error: " // trim(adjustl(message)))
+               call io_log_one_message(FRAGGLE_LOG_OUT, "Fraggle failed due to high angular momentum error: " // &
+                                                        trim(adjustl(message)))
                cycle
             end if
 
@@ -131,9 +133,11 @@ module subroutine fraggle_generate_fragments(self, colliders, system, param, lfa
 
          write(message,*) try
          if (lfailure) then
-            call io_log_one_message(FRAGGLE_LOG_OUT, "Fraggle fragment generation failed after " // trim(adjustl(message)) // " tries")
+            call io_log_one_message(FRAGGLE_LOG_OUT, "Fraggle fragment generation failed after " // &
+                                                      trim(adjustl(message)) // " tries")
          else
-            call io_log_one_message(FRAGGLE_LOG_OUT, "Fraggle fragment generation succeeded after " // trim(adjustl(message)) // " tries")
+            call io_log_one_message(FRAGGLE_LOG_OUT, "Fraggle fragment generation succeeded after " // &
+                                                       trim(adjustl(message)) // " tries")
             call fraggle_io_log_generate(frag)
          end if
 
@@ -240,14 +244,16 @@ subroutine fraggle_generate_spins(frag, colliders, f_spin, lfailure)
          frag%ke_spin = 0.0_DP
          do i = 1, nfrag
             ! Convert a fraction (f_spin) of either the remaining angular momentum or kinetic energy budget into spin, whichever gives the smaller rotation so as not to blow any budgets
-            rot_ke(:) = sqrt(2 * f_spin * frag%ke_budget / (nfrag * frag%mass(i) * frag%radius(i)**2 * frag%Ip(3, i))) * L_remainder(:) / norm2(L_remainder(:))
+            rot_ke(:) = sqrt(2 * f_spin * frag%ke_budget / (nfrag * frag%mass(i) * frag%radius(i)**2 * frag%Ip(3, i))) &
+                        * L_remainder(:) / norm2(L_remainder(:))
             rot_L(:) = f_spin * L_remainder(:) / (nfrag * frag%mass(i) * frag%radius(i)**2 * frag%Ip(3, i))
             if (norm2(rot_ke) < norm2(rot_L)) then
                frag%rot(:,i) = rot_ke(:)
             else
                frag%rot(:, i) = rot_L(:)
             end if
-            frag%ke_spin = frag%ke_spin + frag%mass(i) * frag%Ip(3, i) * frag%radius(i)**2 * dot_product(frag%rot(:, i), frag%rot(:, i))
+            frag%ke_spin = frag%ke_spin + frag%mass(i) * frag%Ip(3, i) * frag%radius(i)**2 &
+                                                       * dot_product(frag%rot(:, i), frag%rot(:, i))
          end do
          frag%ke_spin = 0.5_DP * frag%ke_spin
 
@@ -340,7 +346,8 @@ subroutine fraggle_generate_tan_vel(frag, colliders, lfailure)
          frag%v_t_mag(1:nfrag) = solve_fragment_tan_vel(v_t_mag_input=v_t_initial(7:nfrag), lfailure=lfailure)
 
          ! Perform one final shift of the radial velocity vectors to align with the center of mass of the collisional system (the origin)
-         frag%vb(:,1:nfrag) = fraggle_util_vmag_to_vb(frag%v_r_mag(1:nfrag), frag%v_r_unit(:,1:nfrag), frag%v_t_mag(1:nfrag), frag%v_t_unit(:,1:nfrag), frag%mass(1:nfrag), frag%vbcom(:)) 
+         frag%vb(:,1:nfrag) = fraggle_util_vmag_to_vb(frag%v_r_mag(1:nfrag), frag%v_r_unit(:,1:nfrag), frag%v_t_mag(1:nfrag), &
+                                                      frag%v_t_unit(:,1:nfrag), frag%mass(1:nfrag), frag%vbcom(:)) 
          do concurrent (i = 1:nfrag)
             frag%v_coll(:,i) = frag%vb(:,i) - frag%vbcom(:)
          end do
@@ -506,7 +513,8 @@ subroutine fraggle_generate_rad_vel(frag, colliders, lfailure)
          
          ! Shift the radial velocity vectors to align with the center of mass of the collisional system (the origin)
          frag%ke_orbit = 0.0_DP
-         frag%vb(:,1:nfrag) = fraggle_util_vmag_to_vb(frag%v_r_mag(1:nfrag), frag%v_r_unit(:,1:nfrag), frag%v_t_mag(1:nfrag), frag%v_t_unit(:,1:nfrag), frag%mass(1:nfrag), frag%vbcom(:)) 
+         frag%vb(:,1:nfrag) = fraggle_util_vmag_to_vb(frag%v_r_mag(1:nfrag), frag%v_r_unit(:,1:nfrag), &
+                              frag%v_t_mag(1:nfrag), frag%v_t_unit(:,1:nfrag), frag%mass(1:nfrag), frag%vbcom(:)) 
          do i = 1, nfrag
             frag%v_coll(:, i) = frag%vb(:, i) - frag%vbcom(:)
             frag%ke_orbit = frag%ke_orbit + frag%mass(i) * dot_product(frag%vb(:, i), frag%vb(:, i))
diff --git a/src/fraggle/fraggle_regime.f90 b/src/fraggle/fraggle_regime.f90
index f53888df5..abe5766f0 100644
--- a/src/fraggle/fraggle_regime.f90
+++ b/src/fraggle/fraggle_regime.f90
@@ -50,8 +50,9 @@ module subroutine fraggle_regime_colliders(self, frag, system, param)
          dentot = sum(mass_si(:) * density_si(:)) / mtot 
 
          !! Use the positions and velocities of the parents from indside the step (at collision) to calculate the collisional regime
-         call fraggle_regime_collresolve(Mcb_si, mass_si(jtarg), mass_si(jproj), radius_si(jtarg), radius_si(jproj), x1_si(:), x2_si(:),& 
-               v1_si(:), v2_si(:), density_si(jtarg), density_si(jproj), min_mfrag_si, frag%regime, mlr, mslr, frag%Qloss)
+         call fraggle_regime_collresolve(Mcb_si, mass_si(jtarg), mass_si(jproj), radius_si(jtarg), radius_si(jproj), &
+                                         x1_si(:), x2_si(:), v1_si(:), v2_si(:), density_si(jtarg), density_si(jproj), &
+                                         min_mfrag_si, frag%regime, mlr, mslr, frag%Qloss)
 
          frag%mass_dist(1) = min(max(mlr, 0.0_DP), mtot)
          frag%mass_dist(2) = min(max(mslr, 0.0_DP), mtot)
@@ -73,7 +74,8 @@ module subroutine fraggle_regime_colliders(self, frag, system, param)
    end subroutine fraggle_regime_colliders
 
 
-   subroutine fraggle_regime_collresolve(Mcb, m1, m2, rad1, rad2, xh1, xh2, vb1, vb2, den1, den2, min_mfrag, regime, Mlr, Mslr, Qloss)
+   subroutine fraggle_regime_collresolve(Mcb, m1, m2, rad1, rad2, xh1, xh2, vb1, vb2, den1, den2, min_mfrag, &
+                                         regime, Mlr, Mslr, Qloss)
       !! Author: Jennifer L.L. Pouplin, Carlisle A. Wishard, and David A. Minton
       !!
       !! Determine the collisional regime of two colliding bodies. 
@@ -182,7 +184,8 @@ subroutine fraggle_regime_collresolve(Mcb, m1, m2, rad1, rad2, xh1, xh2, vb1, vb
          Mlr = Mtot
          Mslr = 0.0_DP
          Qloss = 0.0_DP
-         call io_log_one_message(FRAGGLE_LOG_OUT, "Fragments would have mass below the minimum. Converting this collision into a merger.")
+         call io_log_one_message(FRAGGLE_LOG_OUT, &
+                                 "Fragments would have mass below the minimum. Converting this collision into a merger.")
       else 
          if( Vimp < Vescp) then
             regime = COLLRESOLVE_REGIME_MERGE !perfect merging regime
diff --git a/src/fraggle/fraggle_set.f90 b/src/fraggle/fraggle_set.f90
index 4012eda34..6902bfb48 100644
--- a/src/fraggle/fraggle_set.f90
+++ b/src/fraggle/fraggle_set.f90
@@ -212,7 +212,8 @@ module subroutine fraggle_set_natural_scale_factors(self, colliders)
 
       associate(frag => self)
          ! Set scale factors
-         frag%Escale = 0.5_DP * (colliders%mass(1) * dot_product(colliders%vb(:,1), colliders%vb(:,1)) + colliders%mass(2) * dot_product(colliders%vb(:,2), colliders%vb(:,2)))
+         frag%Escale = 0.5_DP * (colliders%mass(1) * dot_product(colliders%vb(:,1), colliders%vb(:,1)) &
+                               + colliders%mass(2)  * dot_product(colliders%vb(:,2), colliders%vb(:,2)))
          frag%dscale = sum(colliders%radius(:))
          frag%mscale = frag%mtot 
          frag%vscale = sqrt(frag%Escale / frag%mscale) 
diff --git a/src/fraggle/fraggle_util.f90 b/src/fraggle/fraggle_util.f90
index f65bd81c5..f2c082242 100644
--- a/src/fraggle/fraggle_util.f90
+++ b/src/fraggle/fraggle_util.f90
@@ -166,7 +166,8 @@ module subroutine fraggle_util_get_energy_momentum(self, colliders, system, para
             lexclude(1:npl_after) = .false.
             lexclude(colliders%idx(1:colliders%ncoll)) = .true.
             if (.not.allocated(tmpsys)) then
-               write(*,*) "Error in fraggle_util_get_energy_momentum. This must be called with lbefore=.true. at least once before calling it with lbefore=.false."
+               write(*,*) "Error in fraggle_util_get_energy_momentum. " // &
+                         " This must be called with lbefore=.true. at least once before calling it with lbefore=.false."
                call util_exit(FAILURE)
             end if
             call fraggle_util_add_fragments_to_system(frag, colliders, tmpsys, tmpparam)
@@ -232,7 +233,8 @@ module subroutine fraggle_util_restructure(self, colliders, try, f_spin, r_max_s
             ! Linearly interpolate the last two failed solution ke deficits to find a new distance value to try
             ke_tot_deficit = ke_tot_deficit - (frag%ke_budget - frag%ke_orbit - frag%ke_spin)
             ke_avg_deficit = ke_tot_deficit / try
-            delta_r = (r_max_start - r_max_start_old) * (ke_avg_deficit_target - ke_avg_deficit_old) / (ke_avg_deficit - ke_avg_deficit_old)
+            delta_r = (r_max_start - r_max_start_old) * (ke_avg_deficit_target - ke_avg_deficit_old) &
+                                                      / (ke_avg_deficit - ke_avg_deficit_old)
             if (abs(delta_r) > delta_r_max) delta_r = sign(delta_r_max, delta_r)
          end if
          r_max_start_old = r_max_start
diff --git a/src/gr/gr.f90 b/src/gr/gr.f90
index 8b6bb1120..b05465e98 100644
--- a/src/gr/gr.f90
+++ b/src/gr/gr.f90
@@ -28,7 +28,8 @@ module pure subroutine gr_kick_getaccb_ns_body(self, system, param)
             rmag = norm2(self%xh(:,i))
             vmag2 = dot_product(self%vh(:,i), self%vh(:,i))
             rdotv = dot_product(self%xh(:,i), self%vh(:,i))
-            self%agr(:, i) = self%mu * inv_c2 / rmag**3 * ((4 * self%mu(i) / rmag - vmag2) * self%xh(:,i) + 4 * rdotv * self%vh(:,i))
+            self%agr(:, i) = self%mu * inv_c2 / rmag**3 * ((4 * self%mu(i) / rmag - vmag2) &
+                           * self%xh(:,i) + 4 * rdotv * self%vh(:,i))
          end do
 
          select type(self)
diff --git a/src/io/io.f90 b/src/io/io.f90
index 7ec71d9ae..18a22ccb9 100644
--- a/src/io/io.f90
+++ b/src/io/io.f90
@@ -29,10 +29,11 @@ module subroutine io_conservation_report(self, param, lterminal)
       associate(system => self, pl => self%pl, cb => self%cb, npl => self%pl%nbody)
          if (((param%out_type == REAL4_TYPE) .or. (param%out_type == REAL8_TYPE)) .and. (param%energy_out /= "")) then
             if (param%lfirstenergy .and. (param%out_stat /= "OLD")) then
-               open(unit = EGYIU, file = param%energy_out, form = "formatted", status = "replace", action = "write", err = 667, iomsg = errmsg)
-               write(EGYIU,EGYHEADER, err = 667, iomsg = errmsg)
+               open(unit=EGYIU, file=param%energy_out, form="formatted", status="replace", action="write", err=667, iomsg=errmsg)
+               write(EGYIU,EGYHEADER, err=667, iomsg=errmsg)
             else
-               open(unit = EGYIU, file = param%energy_out, form = "formatted", status = "old", action = "write", position = "append", err = 667, iomsg = errmsg)
+               open(unit=EGYIU, file=param%energy_out, form="formatted", status="old", action="write", &
+                    position="append", err=667, iomsg=errmsg)
             end if
          end if
 
@@ -177,9 +178,9 @@ module subroutine io_dump_particle_info_base(self, param, idx)
          if (lfirst) then
             select case(param%out_stat)
             case('APPEND')
-               open(unit = LUN, file = param%particle_out, status = 'OLD', position = 'APPEND', form = 'UNFORMATTED', err = 667, iomsg = errmsg)
+               open(unit=LUN, file=param%particle_out, status='OLD', position='APPEND', form='UNFORMATTED', err=667, iomsg=errmsg)
             case('NEW', 'UNKNOWN', 'REPLACE')
-               open(unit = LUN, file = param%particle_out, status = param%out_stat, form = 'UNFORMATTED', err = 667, iomsg = errmsg)
+               open(unit=LUN, file=param%particle_out, status=param%out_stat, form='UNFORMATTED', err=667, iomsg=errmsg)
             case default
                write(*,*) 'Invalid status code',trim(adjustl(param%out_stat))
                call util_exit(FAILURE)
@@ -187,7 +188,7 @@ module subroutine io_dump_particle_info_base(self, param, idx)
 
             lfirst = .false.
          else
-            open(unit = LUN, file = param%particle_out, status = 'OLD', position =  'APPEND', form = 'UNFORMATTED', err = 667, iomsg = errmsg)
+            open(unit=LUN, file=param%particle_out, status='OLD', position= 'APPEND', form='UNFORMATTED', err=667, iomsg=errmsg)
          end if
 
          select type(self)
@@ -760,7 +761,8 @@ module subroutine io_param_reader(self, unit, iotype, v_list, iostat, iomsg)
             iostat = -1
             return
          end if
-         if ((param%in_type /= REAL8_TYPE) .and. (param%in_type /= "ASCII") .and. (param%in_type /= NETCDF_FLOAT_TYPE) .and. (param%in_type /= NETCDF_DOUBLE_TYPE))  then
+         if ((param%in_type /= REAL8_TYPE) .and. (param%in_type /= "ASCII") &
+       .and. (param%in_type /= NETCDF_FLOAT_TYPE) .and. (param%in_type /= NETCDF_DOUBLE_TYPE))  then
             write(iomsg,*) 'Invalid input file type:',trim(adjustl(param%in_type))
             iostat = -1
             return
@@ -788,7 +790,8 @@ module subroutine io_param_reader(self, unit, iotype, v_list, iostat, iomsg)
                iostat = -1
                return
             end if
-            if ((param%out_stat /= "NEW") .and. (param%out_stat /= "REPLACE") .and. (param%out_stat /= "APPEND")  .and. (param%out_stat /= "UNKNOWN")) then
+            if ((param%out_stat /= "NEW") .and. (param%out_stat /= "REPLACE") .and. (param%out_stat /= "APPEND")  &
+          .and. (param%out_stat /= "UNKNOWN")) then
                write(iomsg,*) 'Invalid out_stat: ',trim(adjustl(param%out_stat))
                iostat = -1
                return
@@ -1956,9 +1959,9 @@ module subroutine io_write_discard(self, param)
          end if
          select case(out_stat)
          case('APPEND')
-            open(unit = LUN, file = param%discard_out, status = 'OLD', position = 'APPEND', form = 'FORMATTED', err = 667, iomsg = errmsg)
+            open(unit=LUN, file=param%discard_out, status='OLD', position='APPEND', form='FORMATTED', err=667, iomsg=errmsg)
          case('NEW', 'REPLACE', 'UNKNOWN')
-            open(unit = LUN, file = param%discard_out, status = param%out_stat, form = 'FORMATTED', err = 667, iomsg = errmsg)
+            open(unit=LUN, file=param%discard_out, status=param%out_stat, form='FORMATTED', err=667, iomsg=errmsg)
          case default
             write(*,*) 'Invalid status code for OUT_STAT: ',trim(adjustl(param%out_stat))
             call util_exit(FAILURE)
@@ -2137,9 +2140,9 @@ module subroutine io_write_frame_system(self, param)
          if (lfirst) then
             select case(param%out_stat)
             case('APPEND')
-               open(unit = iu, file = param%outfile, status = 'OLD', position = 'APPEND', form = 'UNFORMATTED', err = 667, iomsg = errmsg)
+               open(unit=iu, file=param%outfile, status='OLD', position='APPEND', form='UNFORMATTED', err=667, iomsg=errmsg)
             case('NEW', 'REPLACE', 'UNKNOWN')
-               open(unit = iu, file = param%outfile, status = param%out_stat, form = 'UNFORMATTED', err = 667, iomsg = errmsg)
+               open(unit=iu, file=param%outfile, status=param%out_stat, form='UNFORMATTED', err=667, iomsg=errmsg)
             case default
                write(*,*) 'Invalid status code for OUT_STAT: ',trim(adjustl(param%out_stat))
                call util_exit(FAILURE)
@@ -2147,7 +2150,7 @@ module subroutine io_write_frame_system(self, param)
    
             lfirst = .false.
          else
-            open(unit = iu, file = param%outfile, status = 'OLD', position =  'APPEND', form = 'UNFORMATTED', err = 667, iomsg = errmsg)
+            open(unit=iu, file=param%outfile, status='OLD', position= 'APPEND', form='UNFORMATTED', err=667, iomsg=errmsg)
          end if
       else if ((param%out_type == NETCDF_FLOAT_TYPE) .or. (param%out_type == NETCDF_DOUBLE_TYPE)) then
 
diff --git a/src/main/swiftest_driver.f90 b/src/main/swiftest_driver.f90
index d4e1f2dc8..1bf4dba8b 100644
--- a/src/main/swiftest_driver.f90
+++ b/src/main/swiftest_driver.f90
@@ -22,8 +22,10 @@ program swiftest_driver
    real(DP)                                   :: old_t_final = 0.0_DP !! Output time at which writing should start, in order to prevent duplicate lines being written for restarts
    type(walltimer)                            :: integration_timer !! Object used for computing elapsed wall time
    real(DP)                                   :: tfrac
-   character(*), parameter                    :: statusfmt   = '("Time = ", ES12.5, "; fraction done = ", F6.3, "; Number of active pl, tp = ", I5, ", ", I5)'
-   character(*), parameter                    :: symbastatfmt   = '("Time = ", ES12.5, "; fraction done = ", F6.3, "; Number of active plm, pl, tp = ", I5, ", ", I5, ", ", I5)'
+   character(*), parameter                    :: statusfmt   = '("Time = ", ES12.5, "; fraction done = ", F6.3, ' // & 
+                                                                '"; Number of active pl, tp = ", I5, ", ", I5)'
+   character(*), parameter                    :: symbastatfmt   = '("Time = ", ES12.5, "; fraction done = ", F6.3, ' // &
+                                                                   '"; Number of active plm, pl, tp = ", I5, ", ", I5, ", ", I5)'
 
    ierr = io_get_args(integrator, param_file_name)
    if (ierr /= 0) then
diff --git a/src/modules/encounter_classes.f90 b/src/modules/encounter_classes.f90
index 5c4e963d6..841037bcb 100644
--- a/src/modules/encounter_classes.f90
+++ b/src/modules/encounter_classes.f90
@@ -83,7 +83,8 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, nenc, ind
          integer(I8B),                            intent(out)   :: nenc   !! Total number of encounters
       end subroutine encounter_check_all_plpl
 
-      module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, nenc, index1, index2, lvdotr)
+      module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
+                                                  nenc, index1, index2, lvdotr)
          use swiftest_classes, only: swiftest_parameters
          implicit none
          class(swiftest_parameters),              intent(inout) :: param  !! Current Swiftest run configuration parameter5s
@@ -148,7 +149,8 @@ module pure subroutine encounter_check_sort_aabb_1D(self, n, extent_arr)
          real(DP), dimension(:),           intent(in)    :: extent_arr !! Array of extents of size 2*n
       end subroutine encounter_check_sort_aabb_1D
 
-      module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x2, v2, renc1, renc2, dt, nenc, index1, index2, lvdotr)
+      module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x2, v2, renc1, renc2, dt, &
+                                                               nenc, index1, index2, lvdotr)
          implicit none
          class(encounter_bounding_box),           intent(inout) :: self       !! Multi-dimensional bounding box structure
          integer(I4B),                            intent(in)    :: n1         !! Number of bodies 1
diff --git a/src/modules/swiftest_classes.f90 b/src/modules/swiftest_classes.f90
index f93fcf517..987375461 100644
--- a/src/modules/swiftest_classes.f90
+++ b/src/modules/swiftest_classes.f90
@@ -1574,7 +1574,8 @@ module subroutine util_set_mu_tp(self, cb)
          class(swiftest_cb), intent(inout) :: cb   !! Swiftest central body object
       end subroutine util_set_mu_tp
 
-      module subroutine util_set_particle_info(self, name, particle_type, status, origin_type, origin_time, collision_id, origin_xh, origin_vh, discard_time, discard_xh, discard_vh, discard_body_id)
+      module subroutine util_set_particle_info(self, name, particle_type, status, origin_type, origin_time, collision_id, &
+                                               origin_xh, origin_vh, discard_time, discard_xh, discard_vh, discard_body_id)
          implicit none
          class(swiftest_particle_info), intent(inout)           :: self
          character(len=*),              intent(in),    optional :: name            !! Non-unique name
diff --git a/src/netcdf/netcdf.f90 b/src/netcdf/netcdf.f90
index d28fcc788..7acc79b02 100644
--- a/src/netcdf/netcdf.f90
+++ b/src/netcdf/netcdf.f90
@@ -250,7 +250,8 @@ module subroutine netcdf_initialize_output(self, param)
 
          call check( nf90_def_var(self%ncid, ORIGIN_TIME_VARNAME, self%out_type, self%id_dimid, self%origin_time_varid) )
             !call check( nf90_def_var_chunking(self%ncid, self%origin_time_varid, NF90_CHUNKED, [self%id_chunk]) )
-         call check( nf90_def_var(self%ncid, ORIGIN_TYPE_VARNAME, NF90_CHAR, [self%str_dimid, self%id_dimid], self%origin_type_varid) )
+         call check( nf90_def_var(self%ncid, ORIGIN_TYPE_VARNAME, NF90_CHAR, [self%str_dimid, self%id_dimid], &
+                                  self%origin_type_varid) )
             !call check( nf90_def_var_chunking(self%ncid, self%origin_type_varid, NF90_CHUNKED, [NAMELEN, self%id_chunk]) )
          call check( nf90_def_var(self%ncid, ORIGIN_XHX_VARNAME, self%out_type, self%id_dimid, self%origin_xhx_varid) )
             !call check( nf90_def_var_chunking(self%ncid, self%origin_xhx_varid, NF90_CHUNKED, [self%id_chunk]) )
@@ -936,7 +937,9 @@ module subroutine netcdf_write_frame_base(self, iu, param)
                select type(self)  
                class is (swiftest_pl)  ! Additional output if the passed polymorphic object is a massive body
                   call check( nf90_put_var(iu%ncid, iu%Gmass_varid, self%Gmass(j), start=[idslot, tslot]) )
-                  if (param%lrhill_present) call check( nf90_put_var(iu%ncid, iu%rhill_varid, self%rhill(j), start=[idslot, tslot]) )
+                  if (param%lrhill_present) then
+                     call check( nf90_put_var(iu%ncid, iu%rhill_varid, self%rhill(j), start=[idslot, tslot]) )
+                  end if
                   if (param%lclose) call check( nf90_put_var(iu%ncid, iu%radius_varid, self%radius(j), start=[idslot, tslot]) )
                   if (param%lrotation) then
                      call check( nf90_put_var(iu%ncid, iu%Ip1_varid, self%Ip(1, j), start=[idslot, tslot]) )
diff --git a/src/rmvs/rmvs_discard.f90 b/src/rmvs/rmvs_discard.f90
index b179178dc..8e3b1d7f0 100644
--- a/src/rmvs/rmvs_discard.f90
+++ b/src/rmvs/rmvs_discard.f90
@@ -30,11 +30,12 @@ module subroutine rmvs_discard_tp(self, system, param)
                      write(idstrj, *) pl%id(iplperP)
                      write(timestr, *) t
                      write(*, *) "Particle "  // trim(adjustl(tp%info(i)%name)) // " (" // trim(adjustl(idstri)) &
-                              // ") q with respect to massive body " // trim(adjustl(pl%info(iplperP)%name)) // " (" // trim(adjustl(idstrj)) &
-                              // ") is too small at t = " // trim(adjustl(timestr))
+                              // ") q with respect to massive body " // trim(adjustl(pl%info(iplperP)%name))   &
+                              // " (" // trim(adjustl(idstrj)) // ") is too small at t = " // trim(adjustl(timestr))
                      tp%ldiscard(i) = .true.
                      tp%lmask(i) = .false.
-                     call tp%info(i)%set_value(status="DISCARDED_PLQ", discard_time=t, discard_xh=tp%xh(:,i), discard_vh=tp%vh(:,i), discard_body_id=pl%id(iplperP))
+                     call tp%info(i)%set_value(status="DISCARDED_PLQ", discard_time=t, discard_xh=tp%xh(:,i), &
+                                               discard_vh=tp%vh(:,i), discard_body_id=pl%id(iplperP))
                   end if
                end if
             end associate
diff --git a/src/rmvs/rmvs_encounter_check.f90 b/src/rmvs/rmvs_encounter_check.f90
index f698ea4f0..bbb5a4382 100644
--- a/src/rmvs/rmvs_encounter_check.f90
+++ b/src/rmvs/rmvs_encounter_check.f90
@@ -36,7 +36,8 @@ module function rmvs_encounter_check_tp(self, param, system, dt) result(lencount
       class is (rmvs_pl)
          associate(tp => self, ntp => self%nbody, npl => pl%nbody)
             tp%plencP(1:ntp) = 0
-            call encounter_check_all_pltp(param, npl, ntp, pl%xbeg, pl%vbeg, tp%xh, tp%vh, pl%renc, dt, nenc, index1, index2, lvdotr)
+            call encounter_check_all_pltp(param, npl, ntp, pl%xbeg, pl%vbeg, tp%xh, tp%vh, pl%renc, dt, & 
+                                          nenc, index1, index2, lvdotr)
 
             lencounter = (nenc > 0_I8B)
             if (lencounter) then
diff --git a/src/rmvs/rmvs_step.f90 b/src/rmvs/rmvs_step.f90
index 673188f0e..76c5a802c 100644
--- a/src/rmvs/rmvs_step.f90
+++ b/src/rmvs/rmvs_step.f90
@@ -483,8 +483,10 @@ subroutine rmvs_make_planetocentric(param, cb, pl, tp)
    
                            do j = 2, npl
                               ipc2hc = plenci%plind(j)
-                              plenci%inner(inner_index)%x(:,j) = pl%inner(inner_index)%x(:, ipc2hc) - cbenci%inner(inner_index)%x(:,1)
-                              plenci%inner(inner_index)%v(:,j) = pl%inner(inner_index)%v(:, ipc2hc) - cbenci%inner(inner_index)%v(:,1)
+                              plenci%inner(inner_index)%x(:,j) = pl%inner(inner_index)%x(:, ipc2hc) &
+                                                                 - cbenci%inner(inner_index)%x(:,1)
+                              plenci%inner(inner_index)%v(:,j) = pl%inner(inner_index)%v(:, ipc2hc) &
+                                                                 - cbenci%inner(inner_index)%v(:,1)
                            end do
                         end do
                         call tpenci%set_mu(cbenci)
@@ -554,7 +556,8 @@ subroutine rmvs_peri_tp(tp, pl, t, dt, lfirst, inner_index, ipleP, param)
                            id2 = tp%id(i)
                            xh2(:) = xpc(:, i) + xh1(:)
                            vh2(:) = xpc(:, i) + vh1(:)
-                           call rmvs_io_write_encounter(t, id1, id2, mu, 0.0_DP, rpl, 0.0_DP, xh1(:), xh2(:), vh1(:), vh2(:), param%enc_out)
+                           call rmvs_io_write_encounter(t, id1, id2, mu, 0.0_DP, rpl, 0.0_DP, &
+                                                        xh1(:), xh2(:), vh1(:), vh2(:), param%enc_out)
                         end if
                         if (tp%lperi(i)) then
                            if (peri < tp%peri(i)) then
diff --git a/src/setup/setup.f90 b/src/setup/setup.f90
index 3f1932d24..e6678effa 100644
--- a/src/setup/setup.f90
+++ b/src/setup/setup.f90
@@ -106,12 +106,15 @@ module subroutine setup_initialize_particle_info_system(self, param)
 
       associate(cb => self%cb, pl => self%pl, npl => self%pl%nbody, tp => self%tp, ntp => self%tp%nbody)
 
-         call cb%info%set_value(particle_type=CB_TYPE_NAME, status="ACTIVE", origin_type="Initial conditions", origin_time=param%t0, origin_xh=[0.0_DP, 0.0_DP, 0.0_DP], origin_vh=[0.0_DP, 0.0_DP, 0.0_DP])
+         call cb%info%set_value(particle_type=CB_TYPE_NAME, status="ACTIVE", origin_type="Initial conditions", &
+                                origin_time=param%t0, origin_xh=[0.0_DP, 0.0_DP, 0.0_DP], origin_vh=[0.0_DP, 0.0_DP, 0.0_DP])
          do i = 1, self%pl%nbody
-            call pl%info(i)%set_value(particle_type=PL_TYPE_NAME, status="ACTIVE", origin_type="Initial conditions", origin_time=param%t0, origin_xh=self%pl%xh(:,i), origin_vh=self%pl%vh(:,i))
+            call pl%info(i)%set_value(particle_type=PL_TYPE_NAME, status="ACTIVE", origin_type="Initial conditions", &
+                                       origin_time=param%t0, origin_xh=self%pl%xh(:,i), origin_vh=self%pl%vh(:,i))
          end do
          do i = 1, self%tp%nbody
-            call tp%info(i)%set_value(particle_type=TP_TYPE_NAME, status="ACTIVE", origin_type="Initial conditions", origin_time=param%t0, origin_xh=self%tp%xh(:,i), origin_vh=self%tp%vh(:,i))
+            call tp%info(i)%set_value(particle_type=TP_TYPE_NAME, status="ACTIVE", origin_type="Initial conditions", &
+                                      origin_time=param%t0, origin_xh=self%tp%xh(:,i), origin_vh=self%tp%vh(:,i))
          end do
 
       end associate
diff --git a/src/symba/symba_collision.f90 b/src/symba/symba_collision.f90
index 8b429a83d..6ebd8532c 100644
--- a/src/symba/symba_collision.f90
+++ b/src/symba/symba_collision.f90
@@ -312,7 +312,8 @@ module function symba_collision_check_encounter(self, system, param, t, dt, irec
                   vr(:) = pl%vb(:, i) - pl%vb(:, j)
                   rlim = pl%radius(i) + pl%radius(j)
                   Gmtot = pl%Gmass(i) + pl%Gmass(j)
-                  lcollision(k) = symba_collision_check_one(xr(1), xr(2), xr(3), vr(1), vr(2), vr(3), Gmtot, rlim, dt, self%lvdotr(k))
+                  lcollision(k) = symba_collision_check_one(xr(1), xr(2), xr(3), vr(1), vr(2), vr(3), &
+                                                            Gmtot, rlim, dt, self%lvdotr(k))
                end do
             else
                do concurrent(k = 1:nenc, lmask(k))
@@ -320,7 +321,8 @@ module function symba_collision_check_encounter(self, system, param, t, dt, irec
                   j = self%index2(k)
                   xr(:) = pl%xh(:, i) - tp%xh(:, j) 
                   vr(:) = pl%vb(:, i) - tp%vb(:, j)
-                  lcollision(k) = symba_collision_check_one(xr(1), xr(2), xr(3), vr(1), vr(2), vr(3), pl%Gmass(i), pl%radius(i), dt, self%lvdotr(k))
+                  lcollision(k) = symba_collision_check_one(xr(1), xr(2), xr(3), vr(1), vr(2), vr(3), &
+                                                            pl%Gmass(i), pl%radius(i), dt, self%lvdotr(k))
                end do
             end if
 
@@ -356,8 +358,8 @@ module function symba_collision_check_encounter(self, system, param, t, dt, irec
                      write(timestr, *) t
                      call tp%info(j)%set_value(status="DISCARDED_PLR", discard_time=t, discard_xh=tp%xh(:,j), discard_vh=tp%vh(:,j))
                      write(message, *) "Particle " // trim(adjustl(tp%info(j)%name)) // " ("  // trim(adjustl(idstrj)) // ")" &
-                             //  " collided with massive body " // trim(adjustl(pl%info(i)%name)) // " (" // trim(adjustl(idstri)) // ")" &
-                             //  " at t = " // trim(adjustl(timestr))
+                             //  " collided with massive body " // trim(adjustl(pl%info(i)%name))  &
+                             // " (" // trim(adjustl(idstri)) // ")" //  " at t = " // trim(adjustl(timestr))
                      call io_log_one_message(FRAGGLE_LOG_OUT, message)
                   end if
                end if
@@ -528,7 +530,9 @@ function symba_collision_consolidate_colliders(pl, cb, param, idx_parent, collid
                   xcrossv(:) = xc(:) .cross. vc(:) 
                   colliders%L_spin(:, j) = colliders%L_spin(:, j) + mchild * xcrossv(:)
 
-                  colliders%L_spin(:, j) = colliders%L_spin(:, j) + mchild * pl%Ip(3, idx_child) * pl%radius(idx_child)**2 * pl%rot(:, idx_child)
+                  colliders%L_spin(:, j) = colliders%L_spin(:, j) + mchild * pl%Ip(3, idx_child)  &
+                                                                           * pl%radius(idx_child)**2 &
+                                                                           * pl%rot(:, idx_child)
                   colliders%Ip(:, j) = colliders%Ip(:, j) + mchild * pl%Ip(:, idx_child)
                end if
 
@@ -748,7 +752,9 @@ subroutine symba_collision_mergeaddsub(system, param, colliders, frag, status)
                   plnew%status(1:nfrag) = NEW_PARTICLE
                   do i = 1, nfrag
                      write(newname, FRAGFMT) frag%id(i)
-                     call plnew%info(i)%set_value(origin_type="Disruption", origin_time=param%t, name=newname, origin_xh=plnew%xh(:,i), origin_vh=plnew%vh(:,i), collision_id=param%maxid_collision)
+                     call plnew%info(i)%set_value(origin_type="Disruption", origin_time=param%t, name=newname, &
+                                                  origin_xh=plnew%xh(:,i), &
+                                                  origin_vh=plnew%vh(:,i), collision_id=param%maxid_collision)
                   end do
                   do i = 1, ncolliders
                      if (colliders%idx(i) == ibiggest) then
@@ -756,13 +762,16 @@ subroutine symba_collision_mergeaddsub(system, param, colliders, frag, status)
                      else
                         iother = ibiggest
                      end if
-                     call pl%info(colliders%idx(i))%set_value(status="Disruption", discard_time=param%t, discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), discard_body_id=iother)
+                     call pl%info(colliders%idx(i))%set_value(status="Disruption", discard_time=param%t, &
+                                                              discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), discard_body_id=iother)
                   end do
                case(SUPERCATASTROPHIC)
                   plnew%status(1:nfrag) = NEW_PARTICLE
                   do i = 1, nfrag
                      write(newname, FRAGFMT) frag%id(i)
-                     call plnew%info(i)%set_value(origin_type="Supercatastrophic", origin_time=param%t, name=newname, origin_xh=plnew%xh(:,i), origin_vh=plnew%vh(:,i), collision_id=param%maxid_collision)
+                     call plnew%info(i)%set_value(origin_type="Supercatastrophic", origin_time=param%t, name=newname, &
+                                                  origin_xh=plnew%xh(:,i), origin_vh=plnew%vh(:,i), &
+                                                  collision_id=param%maxid_collision)
                   end do
                   do i = 1, ncolliders
                      if (colliders%idx(i) == ibiggest) then
@@ -770,19 +779,25 @@ subroutine symba_collision_mergeaddsub(system, param, colliders, frag, status)
                      else
                         iother = ibiggest
                      end if
-                     call pl%info(colliders%idx(i))%set_value(status="Supercatastrophic", discard_time=param%t, discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), discard_body_id=iother)
+                     call pl%info(colliders%idx(i))%set_value(status="Supercatastrophic", discard_time=param%t, &
+                                                              discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), &
+                                                              discard_body_id=iother)
                   end do
                case(HIT_AND_RUN_DISRUPT)
                   call plnew%info(1)%copy(pl%info(ibiggest))
                   plnew%status(1) = OLD_PARTICLE
                   do i = 2, nfrag
                      write(newname, FRAGFMT) frag%id(i)
-                     call plnew%info(i)%set_value(origin_type="Hit and run fragment", origin_time=param%t, name=newname, origin_xh=plnew%xh(:,i), origin_vh=plnew%vh(:,i), collision_id=param%maxid_collision)
+                     call plnew%info(i)%set_value(origin_type="Hit and run fragment", origin_time=param%t, name=newname, &
+                                                  origin_xh=plnew%xh(:,i), origin_vh=plnew%vh(:,i), &
+                                                  collision_id=param%maxid_collision)
                   end do
                   do i = 1, ncolliders
                      if (colliders%idx(i) == ibiggest) cycle
                      iother = ibiggest
-                     call pl%info(colliders%idx(i))%set_value(status="Hit and run fragmention", discard_time=param%t, discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), discard_body_id=iother)
+                     call pl%info(colliders%idx(i))%set_value(status="Hit and run fragmention", discard_time=param%t, &
+                                                              discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), &
+                                                              discard_body_id=iother)
                   end do 
                case(MERGED)
                   call plnew%info(1)%copy(pl%info(ibiggest))
@@ -791,7 +806,8 @@ subroutine symba_collision_mergeaddsub(system, param, colliders, frag, status)
                      if (colliders%idx(i) == ibiggest) cycle
 
                      iother = ibiggest
-                     call pl%info(colliders%idx(i))%set_value(status="MERGED", discard_time=param%t, discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), discard_body_id=iother)
+                     call pl%info(colliders%idx(i))%set_value(status="MERGED", discard_time=param%t, discard_xh=pl%xh(:,i), &
+                                                              discard_vh=pl%vh(:,i), discard_body_id=iother)
                   end do 
                end select
    
@@ -991,9 +1007,12 @@ module subroutine symba_collision_resolve_plplenc(self, system, param, t, dt, ir
                do
                   write(timestr,*) t
                   call io_log_one_message(FRAGGLE_LOG_OUT, "")
-                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************************************************************************")
-                  call io_log_one_message(FRAGGLE_LOG_OUT, "Collision between massive bodies detected at time t = " // trim(adjustl(timestr)))
-                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************************************************************************")
+                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************" // &
+                                                           "***********************************************************")
+                  call io_log_one_message(FRAGGLE_LOG_OUT, "Collision between massive bodies detected at time t = " // &
+                                                           trim(adjustl(timestr)))
+                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************" // &
+                                                           "***********************************************************")
                   allocate(tmp_param, source=param)
                   tmp_param%t = t
                   if (param%lfragmentation) then
@@ -1003,7 +1022,7 @@ module subroutine symba_collision_resolve_plplenc(self, system, param, t, dt, ir
                   end if
 
                   ! Destroy the collision list now that the collisions are resolved
-                  call plplcollision_list%setup(0)
+                  call plplcollision_list%setup(0_I8B)
 
                   if ((system%pl_adds%nbody == 0) .and. (system%pl_discards%nbody == 0)) exit
 
diff --git a/src/symba/symba_discard.f90 b/src/symba/symba_discard.f90
index 0ae89587f..385f6f25b 100644
--- a/src/symba/symba_discard.f90
+++ b/src/symba/symba_discard.f90
@@ -36,26 +36,34 @@ subroutine symba_discard_cb_pl(pl, system, param)
                   pl%status(i) = DISCARDED_RMAX
                   write(idstr, *) pl%id(i)
                   write(timestr, *) param%t
-                  write(message, *) trim(adjustl(pl%info(i)%name)) // " (" // trim(adjustl(idstr)) // ")" // " too far from the central body at t = " // trim(adjustl(timestr))
+                  write(message, *) trim(adjustl(pl%info(i)%name)) // " (" // trim(adjustl(idstr)) // ")" // &
+                                    " too far from the central body at t = " // trim(adjustl(timestr))
                   call io_log_one_message(FRAGGLE_LOG_OUT, "")
-                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************************************************************************")
+                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************" // &
+                                                           "***********************************************************")
                   call io_log_one_message(FRAGGLE_LOG_OUT, message)
-                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************************************************************************")
+                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************" // &
+                                                           "***********************************************************")
                   call io_log_one_message(FRAGGLE_LOG_OUT, "")
-                  call pl%info(i)%set_value(status="DISCARDED_RMAX", discard_time=param%t, discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i))
+                  call pl%info(i)%set_value(status="DISCARDED_RMAX", discard_time=param%t, discard_xh=pl%xh(:,i), &
+                                            discard_vh=pl%vh(:,i))
                else if ((param%rmin >= 0.0_DP) .and. (rh2 < rmin2)) then
                   pl%ldiscard(i) = .true.
                   pl%lcollision(i) = .false. 
                   pl%status(i) = DISCARDED_RMIN
                   write(idstr, *) pl%id(i)
                   write(timestr, *) param%t
-                  write(message, *) trim(adjustl(pl%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" // " too close to the central body at t = " // trim(adjustl(timestr))
+                  write(message, *) trim(adjustl(pl%info(i)%name)) // " ("  // trim(adjustl(idstr)) // ")" // &
+                                    " too close to the central body at t = " // trim(adjustl(timestr))
                   call io_log_one_message(FRAGGLE_LOG_OUT, "")
-                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************************************************************************")
+                  call io_log_one_message(FRAGGLE_LOG_OUT, "************************************************************" // &
+                                                           "************************************************************")
                   call io_log_one_message(FRAGGLE_LOG_OUT, message)
-                  call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************************************************************************")
+                  call io_log_one_message(FRAGGLE_LOG_OUT, "************************************************************" // &
+                                                           "************************************************************")
                   call io_log_one_message(FRAGGLE_LOG_OUT, "")
-                  call pl%info(i)%set_value(status="DISCARDED_RMIN", discard_time=param%t, discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), discard_body_id=cb%id)
+                  call pl%info(i)%set_value(status="DISCARDED_RMIN", discard_time=param%t, discard_xh=pl%xh(:,i), &
+                                            discard_vh=pl%vh(:,i), discard_body_id=cb%id)
                else if (param%rmaxu >= 0.0_DP) then
                   rb2 = dot_product(pl%xb(:,i), pl%xb(:,i))
                   vb2 = dot_product(pl%vb(:,i), pl%vb(:,i))
@@ -66,13 +74,17 @@ subroutine symba_discard_cb_pl(pl, system, param)
                      pl%status(i) = DISCARDED_RMAXU
                      write(idstr, *) pl%id(i)
                      write(timestr, *) param%t
-                     write(message, *) trim(adjustl(pl%info(i)%name)) // " (" // trim(adjustl(idstr)) // ")" // " is unbound and too far from barycenter at t = " // trim(adjustl(timestr))
+                     write(message, *) trim(adjustl(pl%info(i)%name)) // " (" // trim(adjustl(idstr)) // ")" // &
+                                       " is unbound and too far from barycenter at t = " // trim(adjustl(timestr))
                      call io_log_one_message(FRAGGLE_LOG_OUT, "")
-                     call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************************************************************************")
+                     call io_log_one_message(FRAGGLE_LOG_OUT, "************************************************************" // &
+                                                              "************************************************************")
                      call io_log_one_message(FRAGGLE_LOG_OUT, message)
-                     call io_log_one_message(FRAGGLE_LOG_OUT, "***********************************************************************************************************************")
+                     call io_log_one_message(FRAGGLE_LOG_OUT, "************************************************************" // &
+                                                              "************************************************************")
                      call io_log_one_message(FRAGGLE_LOG_OUT, "")
-                     call pl%info(i)%set_value(status="DISCARDED_RMAXU", discard_time=param%t, discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i))
+                     call pl%info(i)%set_value(status="DISCARDED_RMAXU", discard_time=param%t, discard_xh=pl%xh(:,i), &
+                                               discard_vh=pl%vh(:,i))
                   end if
                end if
             end if
@@ -138,7 +150,8 @@ subroutine symba_discard_conserve_mtm(pl, system, param, ipl, lescape_body)
             end do 
             Ltot(:) = Ltot(:) - cb%mass * (cb%xb(:) .cross. cb%vb(:))
             system%Lescape(:) = system%Lescape(:) + Ltot(:)
-            if (param%lrotation) system%Lescape(:) = system%Lescape + pl%mass(ipl) * pl%radius(ipl)**2 * pl%Ip(3, ipl) * pl%rot(:, ipl)
+            if (param%lrotation) system%Lescape(:) = system%Lescape + pl%mass(ipl) * pl%radius(ipl)**2 &
+                                                                    * pl%Ip(3, ipl) * pl%rot(:, ipl)
    
          else
             xcom(:) = (pl%mass(ipl) * pl%xb(:, ipl) + cb%mass * cb%xb(:)) / (cb%mass + pl%mass(ipl))
@@ -305,8 +318,10 @@ subroutine symba_discard_peri_pl(pl, system, param)
                      pl%status(i) = DISCARDED_PERI
                      write(timestr, *) param%t
                      write(idstr, *) pl%id(i)
-                     write(*, *) trim(adjustl(pl%info(i)%name)) // " (" // trim(adjustl(idstr)) // ") perihelion distance too small at t = " // trim(adjustl(timestr)) 
-                     call pl%info(i)%set_value(status="DISCARDED_PERI", discard_time=param%t, discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), discard_body_id=system%cb%id)
+                     write(*, *) trim(adjustl(pl%info(i)%name)) // " (" // trim(adjustl(idstr)) // &
+                                 ") perihelion distance too small at t = " // trim(adjustl(timestr)) 
+                     call pl%info(i)%set_value(status="DISCARDED_PERI", discard_time=param%t, &
+                                               discard_xh=pl%xh(:,i), discard_vh=pl%vh(:,i), discard_body_id=system%cb%id)
                   end if
                end if
             end if
diff --git a/src/symba/symba_encounter_check.f90 b/src/symba/symba_encounter_check.f90
index 4f8495440..7281916b2 100644
--- a/src/symba/symba_encounter_check.f90
+++ b/src/symba/symba_encounter_check.f90
@@ -40,7 +40,8 @@ module function symba_encounter_check_pl(self, param, system, dt, irec) result(l
          if (nplt == 0) then
             call encounter_check_all_plpl(param, npl, pl%xh, pl%vh, pl%renc, dt, nenc, index1, index2, lvdotr)
          else
-            call encounter_check_all_plplm(param, nplm, nplt, pl%xh(:,1:nplm), pl%vh(:,1:nplm), pl%xh(:,nplm+1:npl), pl%vh(:,nplm+1:npl), pl%renc(1:nplm), pl%renc(nplm+1:npl), dt, nenc, index1, index2, lvdotr)
+            call encounter_check_all_plplm(param, nplm, nplt, pl%xh(:,1:nplm), pl%vh(:,1:nplm), pl%xh(:,nplm+1:npl), &
+                  pl%vh(:,nplm+1:npl), pl%renc(1:nplm), pl%renc(nplm+1:npl), dt, nenc, index1, index2, lvdotr)
          end if
          
          lany_encounter = nenc > 0_I8B
@@ -146,7 +147,8 @@ module function symba_encounter_check(self, param, system, dt, irec) result(lany
                   j = self%index2(k)
                   xr(:) = tp%xh(:,j) - pl%xh(:,i)
                   vr(:) = tp%vb(:,j) - pl%vb(:,i)
-                  call encounter_check_one(xr(1), xr(2), xr(3), vr(1), vr(2), vr(3), pl%renc(i), dt, lencounter(lidx), self%lvdotr(k))
+                  call encounter_check_one(xr(1), xr(2), xr(3), vr(1), vr(2), vr(3), pl%renc(i), dt, &
+                                           lencounter(lidx), self%lvdotr(k))
                   if (lencounter(lidx)) then
                      rlim2 = (pl%radius(i))**2
                      rji2 = dot_product(xr(:), xr(:))! Check to see if these are physically overlapping bodies first, which we should ignore
diff --git a/src/symba/symba_io.f90 b/src/symba/symba_io.f90
index 3e217bc6a..19e8635db 100644
--- a/src/symba/symba_io.f90
+++ b/src/symba/symba_io.f90
@@ -74,7 +74,8 @@ module subroutine symba_io_param_reader(self, unit, iotype, v_list, iostat, ioms
                         param_value = io_get_token(line, ifirst, ilast, iostat) 
                         read(param_value, *) param%seed(i)
                      end do
-                     param%seed(nseeds_from_file+1:nseeds) = [(param%seed(1) - param%seed(nseeds_from_file) + i, i=nseeds_from_file+1, nseeds)]
+                     param%seed(nseeds_from_file+1:nseeds) = [(param%seed(1) - param%seed(nseeds_from_file) + i, &
+                                                               i=nseeds_from_file+1, nseeds)]
                   end if
                   seed_set = .true.
                end select
@@ -192,9 +193,9 @@ module subroutine symba_io_write_discard(self, param)
             end if
             select case(out_stat)
             case('APPEND')
-               open(unit = LUN, file = param%discard_out, status = 'OLD', position = 'APPEND', form = 'FORMATTED', err = 667, iomsg = errmsg)
+               open(unit=LUN, file=param%discard_out, status='OLD', position='APPEND', form='FORMATTED', err=667, iomsg=errmsg)
             case('NEW', 'REPLACE', 'UNKNOWN')
-               open(unit = LUN, file = param%discard_out, status = param%out_stat, form = 'FORMATTED', err = 667, iomsg = errmsg)
+               open(unit=LUN, file=param%discard_out, status=param%out_stat, form='FORMATTED', err=667, iomsg=errmsg)
             case default
                write(*,*) 'Invalid status code for OUT_STAT: ',trim(adjustl(param%out_stat))
                call util_exit(FAILURE)
@@ -205,7 +206,7 @@ module subroutine symba_io_write_discard(self, param)
                call pl_adds%pv2v(param) 
             end if
 
-            write(LUN, HDRFMT, err = 667, iomsg = errmsg) param%t, pl_discards%nbody, param%lbig_discard
+            write(LUN, HDRFMT, err=667, iomsg=errmsg) param%t, pl_discards%nbody, param%lbig_discard
             iadd = 1
             isub = 1
             do while (iadd <= pl_adds%nbody)
@@ -213,9 +214,9 @@ module subroutine symba_io_write_discard(self, param)
                nsub = pl_discards%ncomp(isub)
                do j = 1, nadd
                   if (iadd <= pl_adds%nbody) then
-                     write(LUN, NAMEFMT, err = 667, iomsg = errmsg) ADD, pl_adds%id(iadd), pl_adds%status(iadd)
-                     write(LUN, VECFMT, err = 667, iomsg = errmsg) pl_adds%xh(1, iadd), pl_adds%xh(2, iadd), pl_adds%xh(3, iadd)
-                     write(LUN, VECFMT, err = 667, iomsg = errmsg) pl_adds%vh(1, iadd), pl_adds%vh(2, iadd), pl_adds%vh(3, iadd)
+                     write(LUN, NAMEFMT, err=667, iomsg=errmsg) ADD, pl_adds%id(iadd), pl_adds%status(iadd)
+                     write(LUN, VECFMT, err=667, iomsg=errmsg) pl_adds%xh(1, iadd), pl_adds%xh(2, iadd), pl_adds%xh(3, iadd)
+                     write(LUN, VECFMT, err=667, iomsg=errmsg) pl_adds%vh(1, iadd), pl_adds%vh(2, iadd), pl_adds%vh(3, iadd)
                   else 
                      exit
                   end if
@@ -223,9 +224,9 @@ module subroutine symba_io_write_discard(self, param)
                end do
                do j = 1, nsub
                   if (isub <= pl_discards%nbody) then
-                     write(LUN, NAMEFMT, err = 667, iomsg = errmsg) SUB, pl_discards%id(isub), pl_discards%status(isub)
-                     write(LUN, VECFMT, err = 667, iomsg = errmsg) pl_discards%xh(1, isub), pl_discards%xh(2, isub), pl_discards%xh(3, isub)
-                     write(LUN, VECFMT, err = 667, iomsg = errmsg) pl_discards%vh(1, isub), pl_discards%vh(2, isub), pl_discards%vh(3, isub)
+                     write(LUN,NAMEFMT,err=667,iomsg=errmsg) SUB, pl_discards%id(isub), pl_discards%status(isub)
+                     write(LUN,VECFMT,err=667,iomsg=errmsg) pl_discards%xh(1,isub), pl_discards%xh(2,isub), pl_discards%xh(3,isub)
+                     write(LUN,VECFMT,err=667,iomsg=errmsg) pl_discards%vh(1,isub), pl_discards%vh(2,isub), pl_discards%vh(3,isub)
                   else
                      exit
                   end if
diff --git a/src/symba/symba_setup.f90 b/src/symba/symba_setup.f90
index cecb4d806..cda5214d0 100644
--- a/src/symba/symba_setup.f90
+++ b/src/symba/symba_setup.f90
@@ -18,9 +18,9 @@ module subroutine symba_setup_initialize_system(self, param)
       ! Call parent method
       associate(system => self)
          call helio_setup_initialize_system(system, param)
-         call system%pltpenc_list%setup(0)
-         call system%plplenc_list%setup(0)
-         call system%plplcollision_list%setup(0)
+         call system%pltpenc_list%setup(0_I8B)
+         call system%plplenc_list%setup(0_I8B)
+         call system%plplcollision_list%setup(0_I8B)
       end associate
 
       return
diff --git a/src/symba/symba_step.f90 b/src/symba/symba_step.f90
index 7bd2ff562..f2daa8846 100644
--- a/src/symba/symba_step.f90
+++ b/src/symba/symba_step.f90
@@ -110,7 +110,8 @@ module subroutine symba_step_set_recur_levels_system(self, ireci)
       ! Internals
       integer(I4B) :: k, irecp
 
-      associate(system => self, plplenc_list => self%plplenc_list, pltpenc_list => self%pltpenc_list, npl => self%pl%nbody, ntp => self%tp%nbody)
+      associate(system => self, plplenc_list => self%plplenc_list, pltpenc_list => self%pltpenc_list, &
+                npl => self%pl%nbody, ntp => self%tp%nbody)
          select type(pl => self%pl)
          class is (symba_pl)
             select type(tp => self%tp)
@@ -119,8 +120,16 @@ module subroutine symba_step_set_recur_levels_system(self, ireci)
 
                if (npl >0) where(pl%levelg(1:npl) == irecp) pl%levelg(1:npl) = ireci
                if (ntp > 0) where(tp%levelg(1:ntp) == irecp) tp%levelg(1:ntp) = ireci
-               if (plplenc_list%nenc > 0) where(plplenc_list%level(1:plplenc_list%nenc) == irecp) plplenc_list%level(1:plplenc_list%nenc) = ireci
-               if (pltpenc_list%nenc > 0) where(pltpenc_list%level(1:pltpenc_list%nenc) == irecp) pltpenc_list%level(1:pltpenc_list%nenc) = ireci
+               if (plplenc_list%nenc > 0) then
+                  where(plplenc_list%level(1:plplenc_list%nenc) == irecp) 
+                     plplenc_list%level(1:plplenc_list%nenc) = ireci
+                  endwhere
+               end if
+               if (pltpenc_list%nenc > 0) then
+                  where(pltpenc_list%level(1:pltpenc_list%nenc) == irecp) 
+                     pltpenc_list%level(1:pltpenc_list%nenc) = ireci
+                  endwhere
+               end if
 
                system%irec = ireci
 
@@ -173,7 +182,8 @@ module recursive subroutine symba_step_recur_system(self, param, t, ireci)
                   nloops = NTENC
                end if
                do j = 1, nloops
-                  lencounter = plplenc_list%encounter_check(param, system, dtl, irecp) .or. pltpenc_list%encounter_check(param, system, dtl, irecp)
+                  lencounter = plplenc_list%encounter_check(param, system, dtl, irecp) &
+                          .or. pltpenc_list%encounter_check(param, system, dtl, irecp)
                    
                   call plplenc_list%kick(system, dth, irecp, 1)
                   call pltpenc_list%kick(system, dth, irecp, 1)
@@ -247,10 +257,10 @@ module subroutine symba_step_reset_system(self, param)
                      pl%ldiscard(1:npl) = .false.
                      pl%lmask(1:npl) = .true.
                      nenc_old = system%plplenc_list%nenc
-                     call system%plplenc_list%setup(0)
+                     call system%plplenc_list%setup(0_I8B)
                      call system%plplenc_list%setup(nenc_old)
-                     system%plplenc_list%nenc = 0
-                     call system%plplcollision_list%setup(0)
+                     system%plplenc_list%nenc = 0_I8B
+                     call system%plplcollision_list%setup(0_I8B)
                      call system%pl%set_renc(0)
                   end if
             
@@ -261,9 +271,9 @@ module subroutine symba_step_reset_system(self, param)
                      tp%lmask(1:ntp) = .true.
                      tp%ldiscard(1:npl) = .false.
                      nenc_old = system%pltpenc_list%nenc
-                     call system%pltpenc_list%setup(0)
+                     call system%pltpenc_list%setup(0_I8B)
                      call system%pltpenc_list%setup(nenc_old)
-                     system%pltpenc_list%nenc = 0
+                     system%pltpenc_list%nenc = 0_I8B
                   end if
 
                   call system%pl_adds%setup(0, param)
diff --git a/src/symba/symba_util.f90 b/src/symba/symba_util.f90
index 892008aea..0cbdc9a4a 100644
--- a/src/symba/symba_util.f90
+++ b/src/symba/symba_util.f90
@@ -569,7 +569,8 @@ module subroutine symba_util_peri_pl(self, system, param)
                      if (pl%isperi(i) == -1) then
                         if (vdotr >= 0.0_DP) then
                            pl%isperi(i) = 0
-                           CALL orbel_xv2aeq(system%Gmtot, pl%xb(1,i), pl%xb(2,i), pl%xb(3,i), pl%vb(1,i), pl%vb(2,i), pl%vb(3,i),  pl%atp(i), e, pl%peri(i))
+                           CALL orbel_xv2aeq(system%Gmtot, pl%xb(1,i), pl%xb(2,i), pl%xb(3,i), pl%vb(1,i), pl%vb(2,i), pl%vb(3,i),&
+                                             pl%atp(i), e, pl%peri(i))
                         end if
                      else
                         if (vdotr > 0.0_DP) then
@@ -603,7 +604,8 @@ module subroutine symba_util_rearray_pl(self, system, param)
       logical, dimension(:), allocatable :: lmask, ldump_mask
       class(symba_plplenc), allocatable :: plplenc_old
       logical :: lencounter
-      integer(I4B), dimension(:), allocatable :: levelg_orig_pl, levelm_orig_pl, levelg_orig_tp, levelm_orig_tp, nplenc_orig_pl, nplenc_orig_tp, ntpenc_orig_pl
+      integer(I4B), dimension(:), allocatable :: levelg_orig_pl, levelm_orig_pl, levelg_orig_tp, levelm_orig_tp
+      integer(I4B), dimension(:), allocatable :: nplenc_orig_pl, nplenc_orig_tp, ntpenc_orig_pl
 
       associate(pl => self, pl_adds => system%pl_adds)
 
diff --git a/src/util/util_peri.f90 b/src/util/util_peri.f90
index a81748d74..d451e3dbd 100644
--- a/src/util/util_peri.f90
+++ b/src/util/util_peri.f90
@@ -29,7 +29,8 @@ module subroutine util_peri_tp(self, system, param)
                if (tp%isperi(i) == -1) then
                   if (vdotr(i) >= 0.0_DP) then
                      tp%isperi(i) = 0
-                     call orbel_xv2aeq(tp%mu(i), tp%xh(1,i), tp%xh(2,i), tp%xh(3,i), tp%vh(1,i), tp%vh(2,i), tp%vh(3,i), tp%atp(i), e, tp%peri(i))
+                     call orbel_xv2aeq(tp%mu(i), tp%xh(1,i), tp%xh(2,i), tp%xh(3,i), tp%vh(1,i), tp%vh(2,i), tp%vh(3,i), &
+                                       tp%atp(i), e, tp%peri(i))
                   end if
                else
                   if (vdotr(i) > 0.0_DP) then
@@ -45,7 +46,8 @@ module subroutine util_peri_tp(self, system, param)
                if (tp%isperi(i) == -1) then
                   if (vdotr(i) >= 0.0_DP) then
                      tp%isperi(i) = 0
-                     call orbel_xv2aeq(system%Gmtot, tp%xb(1,i), tp%xb(2,i), tp%xb(3,i), tp%vb(1,i), tp%vb(2,i), tp%vb(3,i), tp%atp(i), e, tp%peri(i))
+                     call orbel_xv2aeq(system%Gmtot, tp%xb(1,i), tp%xb(2,i), tp%xb(3,i), tp%vb(1,i), tp%vb(2,i), tp%vb(3,i), &
+                                       tp%atp(i), e, tp%peri(i))
                   end if
                else
                   if (vdotr(i) > 0.0_DP) then
diff --git a/src/util/util_set.f90 b/src/util/util_set.f90
index 98ee4f497..99dff1e0d 100644
--- a/src/util/util_set.f90
+++ b/src/util/util_set.f90
@@ -98,7 +98,8 @@ module subroutine util_set_mu_tp(self, cb)
       return
    end subroutine util_set_mu_tp
 
-   module subroutine util_set_particle_info(self, name, particle_type, status, origin_type, origin_time, collision_id, origin_xh, origin_vh, discard_time, discard_xh, discard_vh, discard_body_id)
+   module subroutine util_set_particle_info(self, name, particle_type, status, origin_type, origin_time, collision_id, origin_xh,&
+                                            origin_vh, discard_time, discard_xh, discard_vh, discard_body_id)
       !! author: David A. Minton
       !!
       !! Sets one or more values of the particle information metadata object
diff --git a/src/walltime/walltime.f90 b/src/walltime/walltime.f90
index a8d82c2b5..87b0a33c2 100644
--- a/src/walltime/walltime.f90
+++ b/src/walltime/walltime.f90
@@ -39,7 +39,8 @@ module subroutine walltime_report(self, nsubsteps, message)
       integer(I4B),               intent(in)    :: nsubsteps !! Number of substeps used to compute the time per step 
       character(len=*),           intent(in)    :: message   !! Message to prepend to the wall time terminal output
       ! Internals
-      character(len=*), parameter     :: walltimefmt = '" Total wall time: ", es12.5, "; Interval wall time: ", es12.5, "; Interval wall time/step:  ", es12.5'
+      character(len=*), parameter     :: walltimefmt = '" Total wall time: ", es12.5, "; Interval wall time: ", es12.5, ";' //&
+                                                       'Interval wall time/step:  ", es12.5'
       character(len=STRMAX)           :: fmt
       integer(I8B)                    :: count_delta_step, count_delta_main, count_now
       real(DP)                        :: wall_main         !! Value of total elapsed time at the end of a timed step
@@ -196,7 +197,8 @@ module subroutine walltime_interaction_adapt(self, param, ninteractions, pl)
 
       write(cstr,*) self%count_stop_step - self%count_start_step
 
-      call io_log_one_message(logfile, adjustl(lstyle) // " " // trim(adjustl(cstr)) // " " // trim(adjustl(nstr)) // " " // trim(adjustl(mstr)))
+      call io_log_one_message(logfile, adjustl(lstyle) // " " // trim(adjustl(cstr)) // " " // &
+                                       trim(adjustl(nstr)) // " " // trim(adjustl(mstr)))
 
       if (self%stage == 2) then
          if (ladvanced_final) then
@@ -204,7 +206,8 @@ module subroutine walltime_interaction_adapt(self, param, ninteractions, pl)
          else
             lstyle = standardstyle
          end if 
-         call io_log_one_message(logfile, trim(adjustl(self%loopname)) // ": the fastest loop method tested is " // trim(adjustl(lstyle)))
+         call io_log_one_message(logfile, trim(adjustl(self%loopname)) // &
+                                 ": the fastest loop method tested is " // trim(adjustl(lstyle)))
       end if
 
       return

From 5b000019cde64eeb281ddc54fc838b8fa0831f7b Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Tue, 23 Nov 2021 16:16:59 -0500
Subject: [PATCH 17/24] Fixed typo that was preventing any encounters from
 being found in the sort & sweep method

---
 src/encounter/encounter_check.f90 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index ccd3d23ce..763243b81 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -1020,7 +1020,7 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
          endwhere
          llist1(:) = ext_ind_true(:) <= n1
 
-         loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) > (self%aabb(1)%iend(:) - 1_I8B)
+         loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
          where(.not.loverlap(:)) lenc(:)%nenc = 0
 
          call timer1%start()
@@ -1124,7 +1124,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
             ext_ind_true(:) = ext_ind(:)
          endwhere
 
-         loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) > (self%aabb(1)%iend(:) - 1_I8B)
+         loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
          where(.not.loverlap(:)) lenc(:)%nenc = 0
 
          call timer1%start()

From e08ed097e82ce3be57e3c3e61abe1b0685ef2d6f Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Tue, 23 Nov 2021 17:00:27 -0500
Subject: [PATCH 18/24] Fixed issue involving reading in NetCDF files when
 there are no test particles (and/or no planets)

---
 src/netcdf/netcdf.f90 | 80 ++++++++++++++++++++++---------------------
 1 file changed, 41 insertions(+), 39 deletions(-)

diff --git a/src/netcdf/netcdf.f90 b/src/netcdf/netcdf.f90
index 7acc79b02..6c1e05e7a 100644
--- a/src/netcdf/netcdf.f90
+++ b/src/netcdf/netcdf.f90
@@ -544,55 +544,55 @@ module function netcdf_read_frame_system(self, iu, param) result(ierr)
          ! Now read in each variable and split the outputs by body type
          if ((param%in_form == XV) .or. (param%in_form == XVEL)) then
             call check( nf90_get_var(iu%ncid, iu%xhx_varid, rtemp, start=[1, tslot]) )
-            pl%xh(1,:) = pack(rtemp, plmask)
-            tp%xh(1,:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%xh(1,:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%xh(1,:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%xhy_varid, rtemp, start=[1, tslot]) )
-            pl%xh(2,:) = pack(rtemp, plmask)
-            tp%xh(2,:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%xh(2,:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%xh(2,:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%xhz_varid, rtemp, start=[1, tslot]) )
-            pl%xh(3,:) = pack(rtemp, plmask)
-            tp%xh(3,:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%xh(3,:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%xh(3,:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%vhx_varid, rtemp, start=[1, tslot]) )
-            pl%vh(1,:) = pack(rtemp, plmask)
-            tp%vh(1,:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%vh(1,:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%vh(1,:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%vhy_varid, rtemp, start=[1, tslot]) )
-            pl%vh(2,:) = pack(rtemp, plmask)
-            tp%vh(2,:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%vh(2,:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%vh(2,:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%vhz_varid, rtemp, start=[1, tslot]) )
-            pl%vh(3,:) = pack(rtemp, plmask)
-            tp%vh(3,:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%vh(3,:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%vh(3,:) = pack(rtemp, tpmask)
          end if
 
          if ((param%in_form == EL)  .or. (param%in_form == XVEL)) then
 
             call check( nf90_get_var(iu%ncid, iu%a_varid, rtemp, start=[1, tslot]) )
-            pl%a(:) = pack(rtemp, plmask)
-            tp%a(:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%a(:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%a(:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%e_varid, rtemp, start=[1, tslot]) )
-            pl%e(:) = pack(rtemp, plmask)
-            tp%e(:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%e(:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%e(:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%inc_varid, rtemp, start=[1, tslot]) )
-            pl%inc(:) = pack(rtemp, plmask)
-            tp%inc(:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%inc(:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%inc(:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%capom_varid, rtemp, start=[1, tslot]) )
-            pl%capom(:) = pack(rtemp, plmask)
-            tp%capom(:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%capom(:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%capom(:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%omega_varid, rtemp, start=[1, tslot]) )
-            pl%omega(:) = pack(rtemp, plmask)
-            tp%omega(:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%omega(:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%omega(:) = pack(rtemp, tpmask)
 
             call check( nf90_get_var(iu%ncid, iu%capm_varid, rtemp, start=[1, tslot]) )
-            pl%capm(:) = pack(rtemp, plmask)
-            tp%capm(:) = pack(rtemp, tpmask)
+            if (npl > 0) pl%capm(:) = pack(rtemp, plmask)
+            if (ntp > 0) tp%capm(:) = pack(rtemp, tpmask)
 
          end if
       
@@ -600,57 +600,59 @@ module function netcdf_read_frame_system(self, iu, param) result(ierr)
          cb%Gmass = rtemp(1)
          cb%mass = cb%Gmass / param%GU
 
-         pl%Gmass(:) = pack(rtemp, plmask)
-         pl%mass(:) = pl%Gmass(:) / param%GU
+         if (npl > 0) then
+            pl%Gmass(:) = pack(rtemp, plmask)
+            pl%mass(:) = pl%Gmass(:) / param%GU
 
-         if (param%lrhill_present) then 
-            call check( nf90_get_var(iu%ncid, iu%rhill_varid, rtemp, start=[1, tslot]) )
-            pl%rhill(:) = pack(rtemp, plmask)
+            if (param%lrhill_present) then 
+               call check( nf90_get_var(iu%ncid, iu%rhill_varid, rtemp, start=[1, tslot]) )
+               pl%rhill(:) = pack(rtemp, plmask)
+            end if
          end if
 
          if (param%lclose) then
             call check( nf90_get_var(iu%ncid, iu%radius_varid, rtemp, start=[1, tslot]) )
             cb%radius = rtemp(1)
-            pl%radius(:) = pack(rtemp, plmask)
+            if (npl > 0) pl%radius(:) = pack(rtemp, plmask)
          else
             cb%radius = param%rmin
-            pl%radius(:) = 0.0_DP
+            if (npl > 0) pl%radius(:) = 0.0_DP
          end if
 
          if (param%lrotation) then
             call check( nf90_get_var(iu%ncid, iu%Ip1_varid,  rtemp, start=[1, tslot]) )
             cb%Ip(1) = rtemp(1)
-            pl%Ip(1,:) = pack(rtemp, plmask)
+            if (npl > 0) pl%Ip(1,:) = pack(rtemp, plmask)
 
             call check( nf90_get_var(iu%ncid, iu%Ip2_varid,  rtemp, start=[1, tslot]) )
             cb%Ip(2) = rtemp(1)
-            pl%Ip(2,:) = pack(rtemp, plmask)
+            if (npl > 0) pl%Ip(2,:) = pack(rtemp, plmask)
 
             call check( nf90_get_var(iu%ncid, iu%Ip3_varid,  rtemp, start=[1, tslot]) )
             cb%Ip(3) = rtemp(1)
-            pl%Ip(3,:) = pack(rtemp, plmask)
+            if (npl > 0) pl%Ip(3,:) = pack(rtemp, plmask)
 
             call check( nf90_get_var(iu%ncid, iu%rotx_varid, rtemp, start=[1, tslot]) )
             cb%rot(1) = rtemp(1)
-            pl%rot(1,:) = pack(rtemp, plmask)
+            if (npl > 0) pl%rot(1,:) = pack(rtemp, plmask)
 
             call check( nf90_get_var(iu%ncid, iu%roty_varid, rtemp, start=[1, tslot]) )
             cb%rot(2) = rtemp(1)
-            pl%rot(2,:) = pack(rtemp, plmask)
+            if (npl > 0) pl%rot(2,:) = pack(rtemp, plmask)
 
             call check( nf90_get_var(iu%ncid, iu%rotz_varid, rtemp, start=[1, tslot]) )
             cb%rot(3) = rtemp(1)
-            pl%rot(3,:) = pack(rtemp, plmask)
+            if (npl > 0) pl%rot(3,:) = pack(rtemp, plmask)
          end if
 
          if (param%ltides) then
             call check( nf90_get_var(iu%ncid, iu%k2_varid, rtemp, start=[1, tslot]) )
             cb%k2 = rtemp(1)
-            pl%k2(:) = pack(rtemp, plmask)
+            if (npl > 0) pl%k2(:) = pack(rtemp, plmask)
 
             call check( nf90_get_var(iu%ncid, iu%Q_varid,  rtemp,  start=[1, tslot]) )
             cb%Q = rtemp(1)
-            pl%Q(:) = pack(rtemp, plmask)
+            if (npl > 0) pl%Q(:) = pack(rtemp, plmask)
          end if
 
          call self%read_particle_info(iu, param, plmask, tpmask) 

From 1052bd52cba717ded984823036c5e42956429a8c Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Tue, 23 Nov 2021 17:12:04 -0500
Subject: [PATCH 19/24] Fixed typo in OpenMP directive

---
 src/kick/kick.f90 | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/kick/kick.f90 b/src/kick/kick.f90
index c3e37d927..e680fde98 100644
--- a/src/kick/kick.f90
+++ b/src/kick/kick.f90
@@ -190,7 +190,7 @@ module subroutine kick_getacch_int_all_triangular_pl(npl, nplm, x, Gmass, radius
          !$omp end parallel do
       else
          !$omp parallel do default(private) schedule(static)&
-         !$omp shared(npl, nplm, x, Gmass, radius) &
+         !$omp shared(npl, nplm, x, Gmass) &
          !$omp lastprivate(rji2, xr, yr, zr) &
          !$omp reduction(+:ahi) &
          !$omp reduction(-:ahj) 

From f4a58c629ef14d4f6ba9949e31ce8958ec271769 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Mon, 29 Nov 2021 13:08:30 -0500
Subject: [PATCH 20/24] Streamlined walltimer functions (no longer need to call
 reset the first time). Also significantly improved the performance of the
 sortsweep encounter checker.

---
 src/encounter/encounter_check.f90 | 289 ++++++++++++++----------------
 src/main/swiftest_driver.f90      |   3 +-
 src/modules/encounter_classes.f90 |   2 +-
 src/modules/walltime_classes.f90  |   4 +-
 src/walltime/walltime.f90         |  25 ++-
 5 files changed, 160 insertions(+), 163 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 763243b81..57f7615f2 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -71,13 +71,11 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, &
       logical, save :: skipit = .false. ! This will be used to ensure that the sort & sweep subroutine gets called at least once before timing it so that the extent array is nearly sorted when it is timed
       integer(I8B) :: nplpl = 0_I8B
       integer(I8B) :: k
-      type(walltimer), save :: timer
 
       if (param%ladaptive_encounters_plpl .and. (.not. skipit)) then
          nplpl = (npl * (npl - 1) / 2) 
          if (nplpl > 0) then
             if (lfirst) then  
-               call timer%reset()
                write(itimer%loopname, *) "encounter_check_all_plpl"
                write(itimer%looptype, *) "ENCOUNTER_PLPL"
                lfirst = .false.
@@ -90,14 +88,11 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, &
          end if
       end if
       
-      call timer%start()
       if (param%lencounter_sas_plpl) then
          call encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, nenc, index1, index2, lvdotr) 
       else
          call encounter_check_all_triangular_plpl(npl, x, v, renc, dt, nenc, index1, index2, lvdotr) 
       end if
-      call timer%stop()
-      call timer%report(nsubsteps=1, message="plpl Encounter check  :")
 
       if (skipit) then
          skipit = .false.
@@ -110,13 +105,6 @@ module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, &
          end if
       end if
 
-      ! TEMP FOR TESTING
-      open(unit=22,file="enclist.csv", status="replace")
-      do k = 1_I8B, nenc
-         write(22,*) index1(k), index2(k)
-      end do
-      close(22)
-
       return
    end subroutine encounter_check_all_plpl
 
@@ -158,14 +146,13 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       integer(I8B), dimension(:), allocatable :: ind
       integer(I4B), dimension(:), allocatable :: itmp
       logical, dimension(:), allocatable :: ltmp
-      type(walltimer), save :: timer
+      type(walltimer) :: timer
 
       if (param%ladaptive_encounters_plpl .and. (.not. skipit)) then
          npl = nplm + nplt
          nplplm = nplm * npl - nplm * (nplm + 1) / 2 
          if (nplplm > 0) then
             if (lfirst) then  
-               call timer%reset()
                write(itimer%loopname, *) "encounter_check_all_plpl"
                write(itimer%looptype, *) "ENCOUNTER_PLPL"
                lfirst = .false.
@@ -184,7 +171,7 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       tmp_param%ladaptive_encounters_plpl = .false.
 
       ! Start with the pl-pl group
-      call timer%start()
+      ! call timer%start()
       call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, nenc, index1, index2, lvdotr)
 
       if (param%lencounter_sas_plpl) then
@@ -194,8 +181,8 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
                                                        plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr) 
       end if
-      call timer%stop()
-      call timer%report(nsubsteps=1, message="plplm Encounter check  :")
+      ! call timer%stop()
+      ! call timer%report("Encounter check pl-plm: ")
 
       if (skipit) then
          skipit = .false.
@@ -228,12 +215,12 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call util_sort_rearrange(index2, ind, nenc)
          call util_sort_rearrange(lvdotr, ind, nenc)
 
-         ! TEMP FOR TESTING
-         open(unit=22,file="enclist.csv", status="replace")
-         do k = 1_I8B, nenc
-            write(22,*) index1(k), index2(k)
-         end do
-         close(22)
+         ! ! TEMP FOR TESTING
+         ! open(unit=22,file="enclist.csv", status="replace")
+         ! do k = 1_I8B, nenc
+         !    write(22,*) index1(k), index2(k)
+         ! end do
+         ! close(22)
       end if
 
       return
@@ -552,9 +539,9 @@ pure subroutine encounter_check_all_sweep_one(i, n, xi, yi, zi, vxi, vyi, vzi, x
       nenci = count(lencounteri(1:n))
       if (nenci > 0_I8B) then
          allocate(lvdotr(nenci), index1(nenci), index2(nenci))
-         lvdotr(:) = pack(lvdotri(1:n), lencounteri(1:n)) 
          index1(:) = i
          index2(:) = pack(ind_arr(1:n), lencounteri(1:n)) 
+         lvdotr(:) = pack(lvdotri(1:n), lencounteri(1:n)) 
       end if
 
       return
@@ -600,8 +587,9 @@ pure subroutine encounter_check_all_triangular_one(i, n, xi, yi, zi, vxi, vyi, v
       if (nenci > 0_I8B) then
          allocate(lenci%lvdotr(nenci), lenci%index1(nenci), lenci%index2(nenci))
          lenci%nenc = nenci
-         lenci%lvdotr(:) = pack(lvdotri(i+1:n), lencounteri(i+1:n)) 
+         lenci%index1(:) = i
          lenci%index2(:) = pack(ind_arr(i+1:n), lencounteri(i+1:n)) 
+         lenci%lvdotr(:) = pack(lvdotri(i+1:n), lencounteri(i+1:n)) 
       end if
 
       return
@@ -751,7 +739,7 @@ subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, ren
    end subroutine encounter_check_all_triangular_pltp
 
 
-   module pure subroutine encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc, dt, lencounter, lvdotr)
+   module elemental subroutine encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc, dt, lencounter, lvdotr)
       !! author: David A. Minton
       !!
       !! Determine whether a test particle and planet are having or will have an encounter within the next time step
@@ -983,93 +971,96 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for body 2 in each encounter candidate pair
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
-      integer(I4B) :: ii, i, ntot
+      integer(I4B) :: ii, i, ntot, nbox
       integer(I8B) :: k
       logical, dimension(n1+n2) :: loverlap
-      logical, dimension(n1) :: lencounter1
-      logical, dimension(n2) :: lencounter2
-      logical, dimension(:), allocatable :: llist1
-      integer(I4B), dimension(:), allocatable :: ext_ind_true
+      logical, dimension(2*(n1+n2)) :: llist1, lencounteri
+      integer(I4B), dimension(2*(n1+n2)) :: ext_ind_true
       type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I8B) :: ibegix, iendix
-      type(walltimer), save :: timer1, timer2, timer3, timer4, timer5
-      logical, save :: lfirst = .true.
-
-      if (lfirst) then
-         call timer1%reset()
-         call timer2%reset()
-         call timer3%reset()
-         call timer4%reset()
-         call timer5%reset()
-         lfirst = .false.
-      end if
+      real(DP), dimension(2*(n1+n2)) :: xind, yind, zind, vxind, vyind, vzind, rencind
+      type(walltimer) :: timer1, timer2, timer3
 
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
+      
+      ! Sweep the intervals for each of the massive bodies along one dimension
+      ! This will build a ragged pair of index lists inside of the lenc data structure
+      where(self%aabb(1)%ind(:) > ntot)
+         ext_ind_true(:) = self%aabb(1)%ind(:)- ntot
+      elsewhere
+         ext_ind_true(:) = self%aabb(1)%ind(:)
+      endwhere
+
+      llist1(:) = ext_ind_true(:) <= n1
+      where(.not.llist1(:)) ext_ind_true(:) = ext_ind_true(:) - n1
+      where(llist1(:))
+         xind(:) = x1(1,ext_ind_true(:))
+         yind(:) = x1(2,ext_ind_true(:))
+         zind(:) = x1(3,ext_ind_true(:))
+         vxind(:) = v1(1,ext_ind_true(:))
+         vyind(:) = v1(2,ext_ind_true(:))
+         vzind(:) = v1(3,ext_ind_true(:))
+         rencind(:) = renc1(ext_ind_true(:))
+      elsewhere
+         xind(:) = x2(1,ext_ind_true(:))
+         yind(:) = x2(2,ext_ind_true(:))
+         zind(:) = x2(3,ext_ind_true(:))
+         vxind(:) = v2(1,ext_ind_true(:))
+         vyind(:) = v2(2,ext_ind_true(:))
+         vzind(:) = v2(3,ext_ind_true(:))
+         rencind(:) = renc2(ext_ind_true(:))
+      endwhere
+
+      loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
+      where(.not.loverlap(:)) lenc(:)%nenc = 0
+
+      ! call timer1%start()
+      ! call timer2%start()
+      !$omp parallel default(private) &
+      !$omp shared(self, ext_ind_true, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, xind, yind, zind, vxind, vyind, vzind, rencind, llist1) &
+      !$omp firstprivate(ntot, n1, n2, dt) 
+     
+      ! Do the first group of bodies (i is in list 1, all the others are from list 2)
+      !$omp do schedule(static)
+      do i = 1, n1
+         if (loverlap(i)) then
+            ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
+            iendix =  self%aabb(1)%iend(i) - 1_I8B
+            nbox = iendix - ibegix + 1
+            lencounteri(ibegix:iendix) = .not.llist1(ibegix:iendix)
+            call encounter_check_all_sweep_one(i, nbox, x1(1,i), x1(2,i), x1(3,i), v1(1,i), v1(2,i), v1(3,i), &
+                                                        xind(ibegix:iendix), yind(ibegix:iendix), zind(ibegix:iendix),&
+                                                        vxind(ibegix:iendix), vyind(ibegix:iendix), vzind(ibegix:iendix), &
+                                                        renc1(i), rencind(ibegix:iendix), dt, ext_ind_true(ibegix:iendix), &
+                                                        lencounteri(ibegix:iendix), lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
+         end if
+      end do
+      !$omp end do nowait
+
+      ! Do the second group of bodies (i is in list 2, all the others are in list 1)
+      !$omp do schedule(static)
+      do i = n1+1, ntot
+         if (loverlap(i)) then
+            ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
+            iendix =  self%aabb(1)%iend(i) - 1_I8B
+            nbox = iendix - ibegix + 1
+            lencounteri(ibegix:iendix) = llist1(ibegix:iendix)
+            ii = i - n1
+            call encounter_check_all_sweep_one(ii, nbox, x2(1,ii), x2(2,ii), x2(3,ii), v2(1,ii), v2(2,ii), v2(3,ii), &
+                                                         xind(ibegix:iendix), yind(ibegix:iendix), zind(ibegix:iendix),&
+                                                         vxind(ibegix:iendix), vyind(ibegix:iendix), vzind(ibegix:iendix), &
+                                                         renc2(ii), rencind(ibegix:iendix), dt, ext_ind_true(ibegix:iendix), &
+                                                         lencounteri(ibegix:iendix), lenc(i)%nenc, lenc(i)%index2, lenc(i)%index1, lenc(i)%lvdotr)
+         end if
+      end do
+      !$omp end do nowait
 
-      associate(ext_ind => self%aabb(1)%ind(:))
-         ! Sweep the intervals for each of the massive bodies along one dimension
-         ! This will build a ragged pair of index lists inside of the lenc data structure
-         allocate(ext_ind_true, mold=ext_ind)
-         allocate(llist1(size(ext_ind)))
-         where(ext_ind(:) > ntot)
-            ext_ind_true(:) = ext_ind(:) - ntot
-         elsewhere
-            ext_ind_true(:) = ext_ind(:)
-         endwhere
-         llist1(:) = ext_ind_true(:) <= n1
-
-         loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
-         where(.not.loverlap(:)) lenc(:)%nenc = 0
-
-         call timer1%start()
-         !$omp parallel do default(private) schedule(static)&
-         !$omp shared(self, ext_ind_true, ind_arr, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
-         !$omp firstprivate(ntot, n1, n2, dt) 
-         do i = 1, n1
-            if (loverlap(i)) then
-               ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
-               iendix =  self%aabb(1)%iend(i) - 1_I8B
-
-               lencounter2(:) = .false.
-               where(.not.llist1(ibegix:iendix)) lencounter2(ext_ind_true(ibegix:iendix) - n1) = .true.
-               call encounter_check_all_sweep_one(i, n2, x1(1,i), x1(2,i), x1(3,i), v1(1,i), v1(2,i), v1(3,i), &
-                                                               x2(1,:), x2(2,:), x2(3,:), v2(1,:), v2(2,:), v2(3,:), &
-                                                               renc1(i), renc2(:), dt, ind_arr, lencounter2(:), &
-                                                               lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
-             end if
-         end do
-         !$omp end parallel do
-         call timer1%stop()
-
-         call timer2%start()
-         !$omp parallel do default(private) schedule(static)&
-         !$omp shared(self, ext_ind_true, ind_arr, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, llist1) &
-         !$omp firstprivate(ntot, n1, dt) 
-         do i = n1+1, ntot
-            if (loverlap(i)) then
-               ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
-               iendix =  self%aabb(1)%iend(i) - 1_I8B
-               lencounter1(:) = .false.
-               where(llist1(ibegix:iendix)) lencounter1(ext_ind_true(ibegix:iendix)) = .true.
-               ii = i - n1
-               call encounter_check_all_sweep_one(ii, n1, x2(1,ii), x2(2,ii), x2(3,ii), v2(1,ii), v2(2,ii), v2(3,ii), &
-                                                                x1(1, :), x1(2, :), x1(3, :), v1(1, :), v1(2, :), v1(3, :), &
-                                                                renc2(ii), renc1(:), dt, ind_arr, lencounter1(:), &
-                                                                lenc(i)%nenc, lenc(i)%index2, lenc(i)%index1, lenc(i)%lvdotr)
-            end if
-         end do
-         !$omp end parallel do
-         call timer2%stop()
-
-         write(*,*) 'double list'
-         call timer1%report(nsubsteps=1, message="timer1           :")
-         call timer2%report(nsubsteps=1, message="timer2           :")
-         ! call timer3%report(nsubsteps=1, message="timer3           :")
-         ! call timer4%report(nsubsteps=1, message="timer4           :")
-         ! call timer5%report(nsubsteps=1, message="timer5           :")
-      end associate
+      !$omp end parallel
+      ! call timer1%stop()
+
+      ! call timer1%report("timer1: ")
 
       call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2, lvdotr)
 
@@ -1096,60 +1087,58 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for the other body in each encounter candidate pair
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
-      integer(I4B) :: ii, i
+      integer(I4B) :: i, nbox
       integer(I8B) :: k, itmp
       logical, dimension(n) :: loverlap
-      logical, dimension(n) :: lencounteri
-      integer(I4B), dimension(:), allocatable :: ext_ind_true
+      logical, dimension(2*n) :: lencounteri
+      real(DP), dimension(2*n) :: xind, yind, zind, vxind, vyind, vzind, rencind
+      integer(I4B), dimension(2*n) :: ext_ind_true
       type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I8B) :: ibegix, iendix
-      type(walltimer), save :: timer1
-      logical, save :: lfirst = .true.
-
-      if (lfirst) then
-         call timer1%reset()
-         lfirst = .false.
-      end if
+      type(walltimer) :: timer0
 
       call util_index_array(ind_arr, n)
 
-      associate(ext_ind => self%aabb(1)%ind(:))
-         ! Sweep the intervals for each of the massive bodies along one dimension
-         ! This will build a ragged pair of index lists inside of the lenc data structure
-         allocate(ext_ind_true, mold=ext_ind)
-         where(ext_ind(:) > n)
-            ext_ind_true(:) = ext_ind(:) - n
-         elsewhere
-            ext_ind_true(:) = ext_ind(:)
-         endwhere
-
-         loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
-         where(.not.loverlap(:)) lenc(:)%nenc = 0
-
-         call timer1%start()
-         !$omp parallel do default(private) schedule(static)&
-         !$omp shared(self, ext_ind_true, ind_arr, lenc, loverlap, x, v, renc) &
-         !$omp firstprivate(n, dt) 
-         do i = 1, n
-            if (loverlap(i)) then
-               ibegix = self%aabb(1)%ibeg(i) + 1_I8B
-               iendix = self%aabb(1)%iend(i) - 1_I8B
-
-               lencounteri(:) = .false.
-               lencounteri(ext_ind_true(ibegix:iendix)) = .true.
-               call encounter_check_all_sweep_one(i, n, x(1,i), x(2,i), x(3,i), v(1,i), v(2,i), v(3,i), &
-                                                        x(1,:), x(2,:), x(3,:), v(1,:), v(2,:), v(3,:), &
-                                                        renc(i), renc(:), dt, ind_arr, lencounteri(:), &
-                                                        lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
-             end if
-         end do
-         !$omp end parallel do
-         call timer1%stop()
-
-         write(*,*) 'single list'
-         call timer1%report(nsubsteps=1, message="timer1           :")
-      end associate
+      ! Sweep the intervals for each of the massive bodies along one dimension
+      ! This will build a ragged pair of index lists inside of the lenc data structure
+      where(self%aabb(1)%ind(:) > n)
+         ext_ind_true(:) = self%aabb(1)%ind(:) - n
+      elsewhere
+         ext_ind_true(:) = self%aabb(1)%ind(:)
+      endwhere
+
+      xind(:) = x(1,ext_ind_true(:))
+      yind(:) = x(2,ext_ind_true(:))
+      zind(:) = x(3,ext_ind_true(:))
+      vxind(:) = v(1,ext_ind_true(:))
+      vyind(:) = v(2,ext_ind_true(:))
+      vzind(:) = v(3,ext_ind_true(:))
+      rencind(:) = renc(ext_ind_true(:))
+
+      loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
+      where(.not.loverlap(:)) lenc(:)%nenc = 0
+
+      ! call timer0%start()
+      !$omp parallel do default(private) schedule(static)&
+      !$omp shared(self, ext_ind_true, lenc, loverlap, x, v, renc, xind, yind, zind, vxind, vyind, vzind, rencind) &
+      !$omp firstprivate(n, dt) 
+      do i = 1, n
+         if (loverlap(i)) then
+            ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
+            iendix =  self%aabb(1)%iend(i) - 1_I8B
+            nbox = iendix - ibegix + 1
+            lencounteri(ibegix:iendix) = .true.
+            call encounter_check_all_sweep_one(i, nbox, x(1,i), x(2,i), x(3,i), v(1,i), v(2,i), v(3,i), &
+                                                      xind(ibegix:iendix), yind(ibegix:iendix), zind(ibegix:iendix),&
+                                                      vxind(ibegix:iendix), vyind(ibegix:iendix), vzind(ibegix:iendix), &
+                                                      renc(i), rencind(ibegix:iendix), dt, ext_ind_true(ibegix:iendix), &
+                                                      lencounteri(ibegix:iendix), lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
+            end if
+      end do
+      !$omp end parallel do
+      ! call timer0%stop()
+      ! call timer0%report("timer0: ")
 
       call encounter_check_collapse_ragged_list(lenc, n, nenc, index1, index2, lvdotr)
 
diff --git a/src/main/swiftest_driver.f90 b/src/main/swiftest_driver.f90
index 1bf4dba8b..afc62fddf 100644
--- a/src/main/swiftest_driver.f90
+++ b/src/main/swiftest_driver.f90
@@ -79,7 +79,6 @@ program swiftest_driver
       !$ write(*,'(a,i3,/)') ' Number of threads  = ', nthreads 
       write(*, *) " *************** Main Loop *************** "
       if (param%lrestart .and. param%lenergy) call nbody_system%conservation_report(param, lterminal=.true.)
-      call integration_timer%reset()
       do iloop = 1, nloops
          !> Step the system forward in time
          call integration_timer%start()
@@ -107,7 +106,7 @@ program swiftest_driver
                   write(*, statusfmt) param%t, tfrac, pl%nbody, nbody_system%tp%nbody
                end select
                if (param%lenergy) call nbody_system%conservation_report(param, lterminal=.true.)
-               call integration_timer%report(nsubsteps=istep_dump, message="Integration steps:")
+               call integration_timer%report(message="Integration steps:", nsubsteps=istep_dump)
                call integration_timer%reset()
 
                iout = istep_out
diff --git a/src/modules/encounter_classes.f90 b/src/modules/encounter_classes.f90
index 841037bcb..47359527a 100644
--- a/src/modules/encounter_classes.f90
+++ b/src/modules/encounter_classes.f90
@@ -121,7 +121,7 @@ module subroutine encounter_check_all_pltp(param, npl, ntp, xpl, vpl, xtp, vtp,
          logical,      dimension(:), allocatable, intent(out)   :: lvdotr !! Logical flag indicating the sign of v .dot. x
       end subroutine encounter_check_all_pltp
 
-      module pure subroutine encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc, dt, lencounter, lvdotr)
+      module elemental subroutine encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc, dt, lencounter, lvdotr)
          !$omp declare simd(encounter_check_one)
          implicit none
          real(DP), intent(in)  :: xr, yr, zr    !! Relative distance vector components
diff --git a/src/modules/walltime_classes.f90 b/src/modules/walltime_classes.f90
index 7e6c971b4..4bd337ef2 100644
--- a/src/modules/walltime_classes.f90
+++ b/src/modules/walltime_classes.f90
@@ -51,11 +51,11 @@ module walltime_classes
    end type interaction_timer
 
    interface
-      module subroutine walltime_report(self, nsubsteps, message)
+      module subroutine walltime_report(self, message, nsubsteps)
          implicit none
          class(walltimer),           intent(inout) :: self      !! Walltimer object
-         integer(I4B),               intent(in)    :: nsubsteps !! Number of substeps used to compute the time per step 
          character(len=*),           intent(in)    :: message   !! Message to prepend to the wall time terminal output
+         integer(I4B), optional,     intent(in)    :: nsubsteps !! Number of substeps used to compute the time per step 
       end subroutine walltime_report
 
       module subroutine walltime_reset(self)
diff --git a/src/walltime/walltime.f90 b/src/walltime/walltime.f90
index 87b0a33c2..ba9e8ab57 100644
--- a/src/walltime/walltime.f90
+++ b/src/walltime/walltime.f90
@@ -29,18 +29,19 @@ module subroutine walltime_stop(self)
    end subroutine walltime_stop
 
 
-   module subroutine walltime_report(self, nsubsteps, message)
+   module subroutine walltime_report(self, message, nsubsteps)
       !! author: David A. Minton
       !!
       !! Prints the elapsed time information to the terminal
       implicit none
       ! Arguments
       class(walltimer),           intent(inout) :: self      !! Walltimer object
-      integer(I4B),               intent(in)    :: nsubsteps !! Number of substeps used to compute the time per step 
       character(len=*),           intent(in)    :: message   !! Message to prepend to the wall time terminal output
+      integer(I4B), optional,     intent(in)    :: nsubsteps !! Number of substeps used to compute the time per step 
       ! Internals
-      character(len=*), parameter     :: walltimefmt = '" Total wall time: ", es12.5, "; Interval wall time: ", es12.5, ";' //&
-                                                       'Interval wall time/step:  ", es12.5'
+      character(len=*), parameter     :: nosubstepfmt = '" Total wall time: ", es12.5, "; Interval wall time: ", es12.5 ' 
+      character(len=*), parameter     :: substepfmt   = '" Total wall time: ", es12.5, "; Interval wall time: ", es12.5, ";' //&
+                                                        'Interval wall time/step:  ", es12.5'
       character(len=STRMAX)           :: fmt
       integer(I8B)                    :: count_delta_step, count_delta_main, count_now
       real(DP)                        :: wall_main         !! Value of total elapsed time at the end of a timed step
@@ -57,10 +58,15 @@ module subroutine walltime_report(self, nsubsteps, message)
       count_delta_step = count_now - self%count_start_step
       wall_main = count_delta_main / (self%count_rate * 1.0_DP)
       wall_step = count_delta_step / (self%count_rate * 1.0_DP)
-      wall_per_substep = wall_step / nsubsteps
+      if (present(nsubsteps)) then
+         wall_per_substep = wall_step / nsubsteps
+         fmt = '("' //  adjustl(message) // '",' // substepfmt // ')'
+         write(*,trim(adjustl(fmt))) wall_main, self%wall_step, wall_per_substep
+      else
+         fmt = '("' //  adjustl(message) // '",' // nosubstepfmt // ')'
+         write(*,trim(adjustl(fmt))) wall_main, self%wall_step
+      end if
 
-      fmt = '("' //  adjustl(message) // '",' // walltimefmt // ')'
-      write(*,trim(adjustl(fmt))) wall_main, self%wall_step, wall_per_substep
 
       return
    end subroutine walltime_report
@@ -111,7 +117,10 @@ module subroutine walltime_start(self)
       integer(I8B) :: count_resume, count_delta
 
 
-      if (.not.self%main_is_started) call self%start_main()
+      if (.not.self%main_is_started) then
+         call self%reset()
+         call self%start_main()
+      end if
 
       if (self%is_paused) then ! Resume a paused step timer
          call system_clock(count_resume)

From e22c8c14e2ab540e89a7c10b38c69d9434e92cf0 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Wed, 15 Dec 2021 08:15:51 -0500
Subject: [PATCH 21/24] Updated profile branch with re-written encounter
 checking code (still has residual timing calls in it)

---
 src/encounter/encounter_check.f90 | 211 ++++++++++++------------------
 src/modules/encounter_classes.f90 |  14 --
 src/modules/swiftest_classes.f90  |  10 +-
 src/util/util_sort.f90            |  84 ++++++++++++
 4 files changed, 177 insertions(+), 142 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 57f7615f2..003800001 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -2,51 +2,6 @@
    use swiftest
 contains
 
-   module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc1, renc2, dt, &
-                                         lencounter, lvdotr)
-      !! author: David A. Minton
-      !!
-      !! Check for encounters between n pairs of bodies. 
-      !! This implementation is general for any type of body. For instance, for massive bodies, you would pass x1 = x2, for test particles renc2 is an array of zeros, etc.
-      !!
-      implicit none
-      ! Arguments
-      integer(I8B),                 intent(in)  :: nenc       !! Number of encounters in the encounter lists
-      integer(I4B), dimension(:),   intent(in)  :: index1     !! List of indices for body 1 in each encounter
-      integer(I4B), dimension(:),   intent(in)  :: index2     !! List of indices for body 2 in each encounter1
-      real(DP),     dimension(:,:), intent(in)  :: x1, v1     !! Array of indices of bodies 1
-      real(DP),     dimension(:,:), intent(in)  :: x2, v2     !! Array of indices of bodies 2
-      real(DP),     dimension(:),   intent(in)  :: renc1      !! Radius of encounter regions of bodies 1
-      real(DP),     dimension(:),   intent(in)  :: renc2      !! Radius of encounter regions of bodies 2
-      real(DP),                     intent(in)  :: dt         !! Step size
-      logical,      dimension(:),   intent(out) :: lencounter !! Logical array indicating which pairs are in a close encounter state
-      logical,      dimension(:),   intent(out) :: lvdotr     !! Logical array indicating which pairs are approaching
-      ! Internals
-      integer(I4B) :: i, j
-      integer(I8B) :: k
-      real(DP)     :: xr, yr, zr, vxr, vyr, vzr, renc12
-
-      !$omp parallel do simd default(firstprivate) schedule(static)&
-      !$omp shared(lencounter, lvdotr, index1, index2, x1, v1, x2, v2) &
-      !$omp lastprivate(i, j, xr, yr, zr, vxr, vyr, vzr, renc12)
-      do k = 1_I8B, nenc
-         i = index1(k)
-         j = index2(k)
-         xr = x2(1, j) - x1(1, i)
-         yr = x2(2, j) - x1(2, i)
-         zr = x2(3, j) - x1(3, i)
-         vxr = v2(1, j) - v1(1, i)
-         vyr = v2(2, j) - v1(2, i)
-         vzr = v2(3, j) - v1(3, i)
-         renc12 = renc1(i) + renc2(j)
-         call encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc12, dt, lencounter(k), lvdotr(k)) 
-      end do
-      !$omp end parallel do simd
-
-      return
-   end subroutine encounter_check_all
-
-
    module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, &
                                               nenc, index1, index2, lvdotr)
       !! author: David A. Minton
@@ -171,7 +126,7 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       tmp_param%ladaptive_encounters_plpl = .false.
 
       ! Start with the pl-pl group
-      ! call timer%start()
+      !call timer%start()
       call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, nenc, index1, index2, lvdotr)
 
       if (param%lencounter_sas_plpl) then
@@ -181,8 +136,8 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
                                                        plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr) 
       end if
-      ! call timer%stop()
-      ! call timer%report("Encounter check pl-plm: ")
+      !call timer%stop()
+      !call timer%report("Encounter check pl-plm: ")
 
       if (skipit) then
          skipit = .false.
@@ -216,11 +171,11 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call util_sort_rearrange(lvdotr, ind, nenc)
 
          ! ! TEMP FOR TESTING
-         ! open(unit=22,file="enclist.csv", status="replace")
-         ! do k = 1_I8B, nenc
-         !    write(22,*) index1(k), index2(k)
-         ! end do
-         ! close(22)
+         open(unit=22,file="enclist.csv", status="replace")
+         do k = 1_I8B, nenc
+            write(22,*) index1(k), index2(k)
+         end do
+         close(22)
       end if
 
       return
@@ -536,8 +491,8 @@ pure subroutine encounter_check_all_sweep_one(i, n, xi, yi, zi, vxi, vyi, vzi, x
          renc12 = renci + renc(j)
          call encounter_check_one(xr, yr, zr, vxr, vyr, vzr, renc12, dt, lencounteri(j), lvdotri(j))
       end do
-      nenci = count(lencounteri(1:n))
-      if (nenci > 0_I8B) then
+      if (any(lencounteri(:))) then
+         nenci = count(lencounteri(:))
          allocate(lvdotr(nenci), index1(nenci), index2(nenci))
          index1(:) = i
          index2(:) = pack(ind_arr(1:n), lencounteri(1:n)) 
@@ -671,7 +626,7 @@ subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vp
 
       call util_index_array(ind_arr, nplt)
 
-      !$omp parallel do default(private) schedule(static)&
+      !$omp parallel do default(private) schedule(dynamic)&
       !$omp shared(xplm, vplm, xplt, vplt, rencm, renct, lenc, ind_arr) &
       !$omp firstprivate(nplm, nplt, dt)
       do i = 1, nplm
@@ -720,7 +675,7 @@ subroutine encounter_check_all_triangular_pltp(npl, ntp, xpl, vpl, xtp, vtp, ren
       call util_index_array(ind_arr, ntp)
       renct(:) = 0.0_DP
 
-      !$omp parallel do default(private) schedule(static)&
+      !$omp parallel do default(private) schedule(dynamic)&
       !$omp shared(xpl, vpl, xtp, vtp, renc, renct, lenc, ind_arr) &
       !$omp firstprivate(npl, ntp, dt)
       do i = 1, npl
@@ -933,7 +888,6 @@ module pure subroutine encounter_check_sort_aabb_1D(self, n, extent_arr)
       real(DP), dimension(:),           intent(in)    :: extent_arr !! Array of extents of size 2*n
       ! Internals
       integer(I8B) :: i, k
-      logical, dimension(:), allocatable :: lfresh
 
       call util_sort(extent_arr, self%ind)
 
@@ -971,70 +925,78 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for body 2 in each encounter candidate pair
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
-      integer(I4B) :: ii, i, ntot, nbox
+      integer(I4B) :: ii, i, j, ntot, nbox, dim
       integer(I8B) :: k
       logical, dimension(n1+n2) :: loverlap
-      logical, dimension(2*(n1+n2)) :: llist1, lencounteri
-      integer(I4B), dimension(2*(n1+n2)) :: ext_ind_true
+      logical, dimension(SWEEPDIM,n1+n2) :: loverlap_by_dimension
+      integer(I4B), dimension(SWEEPDIM) :: noverlap
+      integer(I8B), dimension(SWEEPDIM) :: ibegi, iendi
+      integer(I4B), dimension(SWEEPDIM,n1+n2) :: nbox_arr
+      logical, dimension(SWEEPDIM,2*(n1+n2)) :: llist1
+      integer(I4B), dimension(SWEEPDIM,2*(n1+n2)) :: ext_ind
+      integer(I4B), dimension(:), allocatable :: x_ind
       type(encounter_list), dimension(n1+n2) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
-      integer(I8B) :: ibegix, iendix
+      integer(I8B) :: ibeg, iend
       real(DP), dimension(2*(n1+n2)) :: xind, yind, zind, vxind, vyind, vzind, rencind
-      type(walltimer) :: timer1, timer2, timer3
+      type(walltimer) :: timer1, timer2, timer3, timer4
 
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
-      
-      ! Sweep the intervals for each of the massive bodies along one dimension
-      ! This will build a ragged pair of index lists inside of the lenc data structure
-      where(self%aabb(1)%ind(:) > ntot)
-         ext_ind_true(:) = self%aabb(1)%ind(:)- ntot
-      elsewhere
-         ext_ind_true(:) = self%aabb(1)%ind(:)
-      endwhere
 
-      llist1(:) = ext_ind_true(:) <= n1
-      where(.not.llist1(:)) ext_ind_true(:) = ext_ind_true(:) - n1
-      where(llist1(:))
-         xind(:) = x1(1,ext_ind_true(:))
-         yind(:) = x1(2,ext_ind_true(:))
-         zind(:) = x1(3,ext_ind_true(:))
-         vxind(:) = v1(1,ext_ind_true(:))
-         vyind(:) = v1(2,ext_ind_true(:))
-         vzind(:) = v1(3,ext_ind_true(:))
-         rencind(:) = renc1(ext_ind_true(:))
+      !call timer1%start()
+      do concurrent(dim = 1:SWEEPDIM)
+         loverlap_by_dimension(dim,:) = (self%aabb(dim)%ibeg(:) + 1_I8B) < (self%aabb(dim)%iend(:) - 1_I8B)
+         where(self%aabb(dim)%ind(:) > ntot)
+            ext_ind(dim,:) = self%aabb(dim)%ind(:) - ntot
+         elsewhere
+            ext_ind(dim,:) = self%aabb(dim)%ind(:)
+         endwhere
+      end do
+      llist1(:,:) = ext_ind(:,:) <= n1
+      where(.not.llist1(:,:)) ext_ind(:,:) = ext_ind(:,:) - n1
+
+      loverlap(:) = loverlap_by_dimension(1,:)
+      do dim = 2, SWEEPDIM
+         loverlap(:) = loverlap(:) .and. loverlap_by_dimension(dim,:)
+      end do
+
+      dim = 1
+      where(llist1(dim,:))
+         xind(:) = x1(1,ext_ind(dim,:))
+         yind(:) = x1(2,ext_ind(dim,:))
+         zind(:) = x1(3,ext_ind(dim,:))
+         vxind(:) = v1(1,ext_ind(dim,:))
+         vyind(:) = v1(2,ext_ind(dim,:))
+         vzind(:) = v1(3,ext_ind(dim,:))
+         rencind(:) = renc1(ext_ind(dim,:))
       elsewhere
-         xind(:) = x2(1,ext_ind_true(:))
-         yind(:) = x2(2,ext_ind_true(:))
-         zind(:) = x2(3,ext_ind_true(:))
-         vxind(:) = v2(1,ext_ind_true(:))
-         vyind(:) = v2(2,ext_ind_true(:))
-         vzind(:) = v2(3,ext_ind_true(:))
-         rencind(:) = renc2(ext_ind_true(:))
+         xind(:) = x2(1,ext_ind(dim,:))
+         yind(:) = x2(2,ext_ind(dim,:))
+         zind(:) = x2(3,ext_ind(dim,:))
+         vxind(:) = v2(1,ext_ind(dim,:))
+         vyind(:) = v2(2,ext_ind(dim,:))
+         vzind(:) = v2(3,ext_ind(dim,:))
+         rencind(:) = renc2(ext_ind(dim,:))
       endwhere
 
-      loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
       where(.not.loverlap(:)) lenc(:)%nenc = 0
-
-      ! call timer1%start()
-      ! call timer2%start()
       !$omp parallel default(private) &
-      !$omp shared(self, ext_ind_true, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, xind, yind, zind, vxind, vyind, vzind, rencind, llist1) &
-      !$omp firstprivate(ntot, n1, n2, dt) 
+      !$omp shared(self, ext_ind, lenc, loverlap, x1, v1, x2, v2, renc1, renc2, xind, yind, zind, vxind, vyind, vzind, rencind, llist1) &
+      !$omp firstprivate(ntot, n1, n2, dt, dim) 
      
       ! Do the first group of bodies (i is in list 1, all the others are from list 2)
       !$omp do schedule(static)
       do i = 1, n1
          if (loverlap(i)) then
-            ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
-            iendix =  self%aabb(1)%iend(i) - 1_I8B
-            nbox = iendix - ibegix + 1
-            lencounteri(ibegix:iendix) = .not.llist1(ibegix:iendix)
+            ibegi =  self%aabb(dim)%ibeg(i) + 1_I8B
+            iendi =  self%aabb(dim)%iend(i) - 1_I8B
+            nbox = iend - ibeg + 1
             call encounter_check_all_sweep_one(i, nbox, x1(1,i), x1(2,i), x1(3,i), v1(1,i), v1(2,i), v1(3,i), &
-                                                        xind(ibegix:iendix), yind(ibegix:iendix), zind(ibegix:iendix),&
-                                                        vxind(ibegix:iendix), vyind(ibegix:iendix), vzind(ibegix:iendix), &
-                                                        renc1(i), rencind(ibegix:iendix), dt, ext_ind_true(ibegix:iendix), &
-                                                        lencounteri(ibegix:iendix), lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
+                                                         xind(ibeg:iend), yind(ibeg:iend), zind(ibeg:iend),&
+                                                         vxind(ibeg:iend), vyind(ibeg:iend), vzind(ibeg:iend), &
+                                                         renc1(i), rencind(ibeg:iend), dt, ext_ind(dim,ibeg:iend), &
+                                                         .not.llist1(dim,ibeg:iend), lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
          end if
       end do
       !$omp end do nowait
@@ -1043,24 +1005,20 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
       !$omp do schedule(static)
       do i = n1+1, ntot
          if (loverlap(i)) then
-            ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
-            iendix =  self%aabb(1)%iend(i) - 1_I8B
-            nbox = iendix - ibegix + 1
-            lencounteri(ibegix:iendix) = llist1(ibegix:iendix)
+            ibeg =  self%aabb(dim)%ibeg(i) + 1_I8B
+            iend =  self%aabb(dim)%iend(i) - 1_I8B
+            nbox = iend - ibeg + 1
             ii = i - n1
             call encounter_check_all_sweep_one(ii, nbox, x2(1,ii), x2(2,ii), x2(3,ii), v2(1,ii), v2(2,ii), v2(3,ii), &
-                                                         xind(ibegix:iendix), yind(ibegix:iendix), zind(ibegix:iendix),&
-                                                         vxind(ibegix:iendix), vyind(ibegix:iendix), vzind(ibegix:iendix), &
-                                                         renc2(ii), rencind(ibegix:iendix), dt, ext_ind_true(ibegix:iendix), &
-                                                         lencounteri(ibegix:iendix), lenc(i)%nenc, lenc(i)%index2, lenc(i)%index1, lenc(i)%lvdotr)
+                                                          xind(ibeg:iend), yind(ibeg:iend), zind(ibeg:iend),&
+                                                          vxind(ibeg:iend), vyind(ibeg:iend), vzind(ibeg:iend), &
+                                                          renc2(ii), rencind(ibeg:iend), dt, ext_ind(dim,ibeg:iend), &
+                                                          llist1(dim,ibeg:iend), lenc(i)%nenc, lenc(i)%index2, lenc(i)%index1, lenc(i)%lvdotr)
          end if
       end do
       !$omp end do nowait
 
       !$omp end parallel
-      ! call timer1%stop()
-
-      ! call timer1%report("timer1: ")
 
       call encounter_check_collapse_ragged_list(lenc, ntot, nenc, index1, index2, lvdotr)
 
@@ -1087,41 +1045,42 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
       integer(I4B), dimension(:), allocatable, intent(out)   :: index2     !! List of indices for the other body in each encounter candidate pair
       logical,      dimension(:), allocatable, intent(out)   :: lvdotr     !! Logical array indicating which pairs are approaching
       ! Internals
-      integer(I4B) :: i, nbox
+      integer(I4B) :: i, nbox, dim
       integer(I8B) :: k, itmp
       logical, dimension(n) :: loverlap
       logical, dimension(2*n) :: lencounteri
       real(DP), dimension(2*n) :: xind, yind, zind, vxind, vyind, vzind, rencind
-      integer(I4B), dimension(2*n) :: ext_ind_true
+      integer(I4B), dimension(SWEEPDIM,2*n) :: ext_ind
       type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I8B) :: ibegix, iendix
       type(walltimer) :: timer0
 
       call util_index_array(ind_arr, n)
+      dim = 1
 
       ! Sweep the intervals for each of the massive bodies along one dimension
       ! This will build a ragged pair of index lists inside of the lenc data structure
       where(self%aabb(1)%ind(:) > n)
-         ext_ind_true(:) = self%aabb(1)%ind(:) - n
+         ext_ind(dim,:) = self%aabb(1)%ind(:) - n
       elsewhere
-         ext_ind_true(:) = self%aabb(1)%ind(:)
+         ext_ind(dim,:) = self%aabb(1)%ind(:)
       endwhere
 
-      xind(:) = x(1,ext_ind_true(:))
-      yind(:) = x(2,ext_ind_true(:))
-      zind(:) = x(3,ext_ind_true(:))
-      vxind(:) = v(1,ext_ind_true(:))
-      vyind(:) = v(2,ext_ind_true(:))
-      vzind(:) = v(3,ext_ind_true(:))
-      rencind(:) = renc(ext_ind_true(:))
+      xind(:) = x(1,ext_ind(dim,:))
+      yind(:) = x(2,ext_ind(dim,:))
+      zind(:) = x(3,ext_ind(dim,:))
+      vxind(:) = v(1,ext_ind(dim,:))
+      vyind(:) = v(2,ext_ind(dim,:))
+      vzind(:) = v(3,ext_ind(dim,:))
+      rencind(:) = renc(ext_ind(dim,:))
 
       loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
       where(.not.loverlap(:)) lenc(:)%nenc = 0
 
       ! call timer0%start()
       !$omp parallel do default(private) schedule(static)&
-      !$omp shared(self, ext_ind_true, lenc, loverlap, x, v, renc, xind, yind, zind, vxind, vyind, vzind, rencind) &
+      !$omp shared(self, ext_ind_x, lenc, loverlap, x, v, renc, xind, yind, zind, vxind, vyind, vzind, rencind) &
       !$omp firstprivate(n, dt) 
       do i = 1, n
          if (loverlap(i)) then
@@ -1132,7 +1091,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
             call encounter_check_all_sweep_one(i, nbox, x(1,i), x(2,i), x(3,i), v(1,i), v(2,i), v(3,i), &
                                                       xind(ibegix:iendix), yind(ibegix:iendix), zind(ibegix:iendix),&
                                                       vxind(ibegix:iendix), vyind(ibegix:iendix), vzind(ibegix:iendix), &
-                                                      renc(i), rencind(ibegix:iendix), dt, ext_ind_true(ibegix:iendix), &
+                                                      renc(i), rencind(ibegix:iendix), dt, ext_ind(dim,ibegix:iendix), &
                                                       lencounteri(ibegix:iendix), lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
             end if
       end do
diff --git a/src/modules/encounter_classes.f90 b/src/modules/encounter_classes.f90
index 47359527a..f7758ef54 100644
--- a/src/modules/encounter_classes.f90
+++ b/src/modules/encounter_classes.f90
@@ -54,20 +54,6 @@ module encounter_classes
    end type
 
    interface
-      module subroutine encounter_check_all(nenc, index1, index2, x1, v1, x2, v2, renc1, renc2, dt, lencounter, lvdotr)
-         implicit none
-         integer(I8B),                 intent(in)  :: nenc         !! Number of encounters in the encounter lists
-         integer(I4B), dimension(:),   intent(in)  :: index1     !! List of indices for body 1 in each encounter
-         integer(I4B), dimension(:),   intent(in)  :: index2     !! List of indices for body 2 in each encounter1
-         real(DP),     dimension(:,:), intent(in)  :: x1, v1     !! Array of indices of bodies 1
-         real(DP),     dimension(:,:), intent(in)  :: x2, v2     !! Array of indices of bodies 2
-         real(DP),     dimension(:),   intent(in)  :: renc1      !! Radius of encounter regions of bodies 1
-         real(DP),     dimension(:),   intent(in)  :: renc2      !! Radius of encounter regions of bodies 2
-         real(DP),                     intent(in)  :: dt         !! Step size
-         logical,      dimension(:),   intent(out) :: lencounter !! Logical array indicating which pairs are in a close encounter state
-         logical,      dimension(:),   intent(out) :: lvdotr     !! Logical array indicating which pairs are approaching
-      end subroutine encounter_check_all
-
       module subroutine encounter_check_all_plpl(param, npl, x, v, renc, dt, nenc, index1, index2, lvdotr)
          use swiftest_classes, only: swiftest_parameters
          implicit none
diff --git a/src/modules/swiftest_classes.f90 b/src/modules/swiftest_classes.f90
index 987375461..86e4304dd 100644
--- a/src/modules/swiftest_classes.f90
+++ b/src/modules/swiftest_classes.f90
@@ -1662,11 +1662,17 @@ module pure subroutine util_sort_index_i4b(arr,ind)
          integer(I4B), dimension(:), allocatable, intent(inout) :: ind
       end subroutine util_sort_index_i4b
 
-      module pure subroutine util_sort_index_i4b_I8Bind(arr,ind)
+      module pure subroutine util_sort_index_I4B_I8Bind(arr,ind)
          implicit none
          integer(I4B), dimension(:), intent(in)  :: arr
          integer(I8B), dimension(:), allocatable, intent(inout) :: ind
-      end subroutine util_sort_index_i4b_I8Bind
+      end subroutine util_sort_index_I4b_I8Bind
+
+      module pure subroutine util_sort_index_I8B_I8Bind(arr,ind)
+         implicit none
+         integer(I8B), dimension(:), intent(in)  :: arr
+         integer(I8B), dimension(:), allocatable, intent(inout) :: ind
+      end subroutine util_sort_index_I8B_I8Bind
 
       module pure subroutine util_sort_sp(arr)
          implicit none
diff --git a/src/util/util_sort.f90 b/src/util/util_sort.f90
index e0dfad022..453c3a2d3 100644
--- a/src/util/util_sort.f90
+++ b/src/util/util_sort.f90
@@ -312,6 +312,34 @@ recursive pure subroutine qsort_I4B_I8Bind(arr, ind)
       return
    end subroutine qsort_I4B_I8Bind
 
+
+   recursive pure subroutine qsort_I8B_I8Bind(arr, ind)
+      !! author: David A. Minton
+      !!
+      !! Sort input I8B array by index in ascending numerical order using quicksort.
+      !!
+      implicit none
+      ! Arguments
+      integer(I8B), dimension(:), intent(inout)          :: arr
+      integer(I8B), dimension(:), intent(out),  optional :: ind
+      ! Internals
+      integer(I8B) :: iq
+
+      if (size(arr) > 1_I8B) then
+         if (present(ind)) then
+            call partition_I8B_I8Bind(arr, iq, ind)
+            call qsort_I8B_I8Bind(arr(:iq-1_I8B),ind(:iq-1_I8B))
+            call qsort_I8B_I8Bind(arr(iq:),  ind(iq:))
+         else
+            call partition_I8B_I8Bind(arr, iq)
+            call qsort_I8B_I8Bind(arr(:iq-1_I8B))
+            call qsort_I8B_I8Bind(arr(iq:))
+         end if
+      end if
+
+      return
+   end subroutine qsort_I8B_I8Bind
+
  
    pure subroutine partition_I4B(arr, marker, ind)
       !! author: David A. Minton
@@ -425,6 +453,62 @@ pure subroutine partition_I4B_I8Bind(arr, marker, ind)
       return
    end subroutine partition_I4B_I8Bind
 
+   pure subroutine partition_I8B_I8Bind(arr, marker, ind)
+      !! author: David A. Minton
+      !!
+      !! Partition function for quicksort on I8B type with I8B index
+      !!
+      implicit none
+      ! Arguments
+      integer(I8B), intent(inout), dimension(:)           :: arr
+      integer(I8B), intent(inout), dimension(:), optional :: ind
+      integer(I8B), intent(out)                           :: marker
+      ! Internals
+      integer(I8B) :: i, j, itmp, narr, ipiv
+      integer(I8B) :: temp
+      integer(I8B) :: x   ! pivot point
+
+      narr = size(arr)
+
+      ! Get center as pivot, as this is likely partially sorted
+      ipiv = narr / 2_I8B
+      x = arr(ipiv)
+      i = 0_I8B
+      j = narr + 1_I8B
+   
+      do
+         j = j - 1_I8B
+         do
+            if (arr(j) <= x) exit
+            j = j - 1_I8B
+         end do
+         i = i + 1_I8B
+         do
+            if (arr(i) >= x) exit
+            i = i + 1_I8B
+         end do
+         if (i < j) then
+            ! exchange A(i) and A(j)
+            temp = arr(i)
+            arr(i) = arr(j)
+            arr(j) = temp
+            if (present(ind)) then
+               itmp = ind(i)
+               ind(i) = ind(j)
+               ind(j) = itmp
+            end if
+         else if (i == j) then
+            marker = i + 1_I8B
+            return
+         else
+            marker = i
+            return
+         endif
+      end do
+  
+      return
+   end subroutine partition_I8B_I8Bind
+
 
    module pure subroutine util_sort_sp(arr)
       !! author: David A. Minton

From 99fdda6379a1bb2044ea9c325e7826cb91f4d804 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Thu, 16 Dec 2021 09:13:56 -0500
Subject: [PATCH 22/24] Fixed incorrect index variables inside sweep loop

---
 src/encounter/encounter_check.f90 | 31 +++++++++++++++----------------
 1 file changed, 15 insertions(+), 16 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 003800001..9055e94fc 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -930,7 +930,6 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
       logical, dimension(n1+n2) :: loverlap
       logical, dimension(SWEEPDIM,n1+n2) :: loverlap_by_dimension
       integer(I4B), dimension(SWEEPDIM) :: noverlap
-      integer(I8B), dimension(SWEEPDIM) :: ibegi, iendi
       integer(I4B), dimension(SWEEPDIM,n1+n2) :: nbox_arr
       logical, dimension(SWEEPDIM,2*(n1+n2)) :: llist1
       integer(I4B), dimension(SWEEPDIM,2*(n1+n2)) :: ext_ind
@@ -989,8 +988,8 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
       !$omp do schedule(static)
       do i = 1, n1
          if (loverlap(i)) then
-            ibegi =  self%aabb(dim)%ibeg(i) + 1_I8B
-            iendi =  self%aabb(dim)%iend(i) - 1_I8B
+            ibeg =  self%aabb(dim)%ibeg(i) + 1_I8B
+            iend =  self%aabb(dim)%iend(i) - 1_I8B
             nbox = iend - ibeg + 1
             call encounter_check_all_sweep_one(i, nbox, x1(1,i), x1(2,i), x1(3,i), v1(1,i), v1(2,i), v1(3,i), &
                                                          xind(ibeg:iend), yind(ibeg:iend), zind(ibeg:iend),&
@@ -1053,7 +1052,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
       integer(I4B), dimension(SWEEPDIM,2*n) :: ext_ind
       type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
-      integer(I8B) :: ibegix, iendix
+      integer(I8B) :: ibeg, iend
       type(walltimer) :: timer0
 
       call util_index_array(ind_arr, n)
@@ -1061,7 +1060,7 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
 
       ! Sweep the intervals for each of the massive bodies along one dimension
       ! This will build a ragged pair of index lists inside of the lenc data structure
-      where(self%aabb(1)%ind(:) > n)
+      where(self%aabb(dim)%ind(:) > n)
          ext_ind(dim,:) = self%aabb(1)%ind(:) - n
       elsewhere
          ext_ind(dim,:) = self%aabb(1)%ind(:)
@@ -1075,24 +1074,24 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
       vzind(:) = v(3,ext_ind(dim,:))
       rencind(:) = renc(ext_ind(dim,:))
 
-      loverlap(:) = (self%aabb(1)%ibeg(:) + 1_I8B) < (self%aabb(1)%iend(:) - 1_I8B)
+      loverlap(:) = (self%aabb(dim)%ibeg(:) + 1_I8B) < (self%aabb(dim)%iend(:) - 1_I8B)
       where(.not.loverlap(:)) lenc(:)%nenc = 0
 
       ! call timer0%start()
       !$omp parallel do default(private) schedule(static)&
-      !$omp shared(self, ext_ind_x, lenc, loverlap, x, v, renc, xind, yind, zind, vxind, vyind, vzind, rencind) &
-      !$omp firstprivate(n, dt) 
+      !$omp shared(self, ext_ind, lenc, loverlap, x, v, renc, xind, yind, zind, vxind, vyind, vzind, rencind) &
+      !$omp firstprivate(n, dt, dim) 
       do i = 1, n
          if (loverlap(i)) then
-            ibegix =  self%aabb(1)%ibeg(i) + 1_I8B
-            iendix =  self%aabb(1)%iend(i) - 1_I8B
-            nbox = iendix - ibegix + 1
-            lencounteri(ibegix:iendix) = .true.
+            ibeg =  self%aabb(dim)%ibeg(i) + 1_I8B
+            iend =  self%aabb(dim)%iend(i) - 1_I8B
+            nbox = iend - ibeg + 1
+            lencounteri(ibeg:iend) = .true.
             call encounter_check_all_sweep_one(i, nbox, x(1,i), x(2,i), x(3,i), v(1,i), v(2,i), v(3,i), &
-                                                      xind(ibegix:iendix), yind(ibegix:iendix), zind(ibegix:iendix),&
-                                                      vxind(ibegix:iendix), vyind(ibegix:iendix), vzind(ibegix:iendix), &
-                                                      renc(i), rencind(ibegix:iendix), dt, ext_ind(dim,ibegix:iendix), &
-                                                      lencounteri(ibegix:iendix), lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
+                                                      xind(ibeg:iend), yind(ibeg:iend), zind(ibeg:iend),&
+                                                      vxind(ibeg:iend), vyind(ibeg:iend), vzind(ibeg:iend), &
+                                                      renc(i), rencind(ibeg:iend), dt, ext_ind(dim,ibeg:iend), &
+                                                      lencounteri(ibeg:iend), lenc(i)%nenc, lenc(i)%index1, lenc(i)%index2, lenc(i)%lvdotr)
             end if
       end do
       !$omp end parallel do

From 59cb5f2a87d15e0ebb1f80f25d2636c657bf6a29 Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Thu, 16 Dec 2021 14:39:55 -0500
Subject: [PATCH 23/24] Removed timer and test file code

---
 src/encounter/encounter_check.f90 | 19 -------------------
 1 file changed, 19 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index 9055e94fc..fd42917a0 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -101,7 +101,6 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       integer(I8B), dimension(:), allocatable :: ind
       integer(I4B), dimension(:), allocatable :: itmp
       logical, dimension(:), allocatable :: ltmp
-      type(walltimer) :: timer
 
       if (param%ladaptive_encounters_plpl .and. (.not. skipit)) then
          npl = nplm + nplt
@@ -126,7 +125,6 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
       tmp_param%ladaptive_encounters_plpl = .false.
 
       ! Start with the pl-pl group
-      !call timer%start()
       call encounter_check_all_plpl(tmp_param, nplm, xplm, vplm, rencm, dt, nenc, index1, index2, lvdotr)
 
       if (param%lencounter_sas_plpl) then
@@ -136,8 +134,6 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vplt, rencm, renct, dt, &
                                                        plmplt_nenc, plmplt_index1, plmplt_index2, plmplt_lvdotr) 
       end if
-      !call timer%stop()
-      !call timer%report("Encounter check pl-plm: ")
 
       if (skipit) then
          skipit = .false.
@@ -170,12 +166,6 @@ module subroutine encounter_check_all_plplm(param, nplm, nplt, xplm, vplm, xplt,
          call util_sort_rearrange(index2, ind, nenc)
          call util_sort_rearrange(lvdotr, ind, nenc)
 
-         ! ! TEMP FOR TESTING
-         open(unit=22,file="enclist.csv", status="replace")
-         do k = 1_I8B, nenc
-            write(22,*) index1(k), index2(k)
-         end do
-         close(22)
       end if
 
       return
@@ -269,7 +259,6 @@ subroutine encounter_check_all_sort_and_sweep_plpl(npl, x, v, renc, dt, nenc, in
       type(encounter_bounding_box), save :: boundingbox
       logical, dimension(:), allocatable :: lencounter
       integer(I2B), dimension(npl) :: vshift_min, vshift_max
-      type(walltimer), save :: timer 
 
       if (npl == 0) return
 
@@ -573,7 +562,6 @@ subroutine encounter_check_all_triangular_plpl(npl, x, v, renc, dt, nenc, index1
       logical, dimension(npl) :: lencounteri, lvdotri
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       type(encounter_list), dimension(npl) :: lenc
-      type(walltimer), save :: timer 
 
       call util_index_array(ind_arr, npl) 
 
@@ -622,7 +610,6 @@ subroutine encounter_check_all_triangular_plplm(nplm, nplt, xplm, vplm, xplt, vp
       logical, dimension(nplt) :: lencounteri, lvdotri
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       type(encounter_list), dimension(nplm) :: lenc
-      type(walltimer), save :: timer 
 
       call util_index_array(ind_arr, nplt)
 
@@ -938,12 +925,10 @@ module subroutine encounter_check_sweep_aabb_double_list(self, n1, n2, x1, v1, x
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I8B) :: ibeg, iend
       real(DP), dimension(2*(n1+n2)) :: xind, yind, zind, vxind, vyind, vzind, rencind
-      type(walltimer) :: timer1, timer2, timer3, timer4
 
       ntot = n1 + n2
       call util_index_array(ind_arr, ntot)
 
-      !call timer1%start()
       do concurrent(dim = 1:SWEEPDIM)
          loverlap_by_dimension(dim,:) = (self%aabb(dim)%ibeg(:) + 1_I8B) < (self%aabb(dim)%iend(:) - 1_I8B)
          where(self%aabb(dim)%ind(:) > ntot)
@@ -1053,7 +1038,6 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
       type(encounter_list), dimension(n) :: lenc         !! Array of encounter lists (one encounter list per body)
       integer(I4B), dimension(:), allocatable, save :: ind_arr
       integer(I8B) :: ibeg, iend
-      type(walltimer) :: timer0
 
       call util_index_array(ind_arr, n)
       dim = 1
@@ -1077,7 +1061,6 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
       loverlap(:) = (self%aabb(dim)%ibeg(:) + 1_I8B) < (self%aabb(dim)%iend(:) - 1_I8B)
       where(.not.loverlap(:)) lenc(:)%nenc = 0
 
-      ! call timer0%start()
       !$omp parallel do default(private) schedule(static)&
       !$omp shared(self, ext_ind, lenc, loverlap, x, v, renc, xind, yind, zind, vxind, vyind, vzind, rencind) &
       !$omp firstprivate(n, dt, dim) 
@@ -1095,8 +1078,6 @@ module subroutine encounter_check_sweep_aabb_single_list(self, n, x, v, renc, dt
             end if
       end do
       !$omp end parallel do
-      ! call timer0%stop()
-      ! call timer0%report("timer0: ")
 
       call encounter_check_collapse_ragged_list(lenc, n, nenc, index1, index2, lvdotr)
 

From 6ec3b65ecf34afc15aecf36f26dc00a4d41b4b6e Mon Sep 17 00:00:00 2001
From: David A Minton <daminton@purdue.edu>
Date: Thu, 16 Dec 2021 14:52:20 -0500
Subject: [PATCH 24/24] Fixed issue with test particle encounter size not being
 defined. Set to zero valued array

---
 src/encounter/encounter_check.f90 | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/src/encounter/encounter_check.f90 b/src/encounter/encounter_check.f90
index fd42917a0..20fcb3bd5 100644
--- a/src/encounter/encounter_check.f90
+++ b/src/encounter/encounter_check.f90
@@ -366,7 +366,7 @@ subroutine encounter_check_all_sort_and_sweep_plplm(nplm, nplt, xplm, vplm, xplt
    end subroutine encounter_check_all_sort_and_sweep_plplm
 
 
-   subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, renc, dt, &
+   subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp, rencpl, dt, &
                                                       nenc, index1, index2, lvdotr)
       !! author: David A. Minton
       !!
@@ -382,7 +382,7 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
       real(DP),     dimension(:,:),            intent(in)  :: vpl    !! Velocity vectors of massive bodies
       real(DP),     dimension(:,:),            intent(in)  :: xtp    !! Position vectors of massive bodies
       real(DP),     dimension(:,:),            intent(in)  :: vtp    !! Velocity vectors of massive bodies
-      real(DP),     dimension(:),              intent(in)  :: renc   !! Critical radii of massive bodies that defines an encounter
+      real(DP),     dimension(:),              intent(in)  :: rencpl !! Critical radii of massive bodies that defines an encounter
       real(DP),                                intent(in)  :: dt     !! Step size
       integer(I8B),                            intent(out) :: nenc   !! Total number of encounter
       integer(I4B), dimension(:), allocatable, intent(out) :: index1 !! List of indices for body 1 in each encounter
@@ -395,7 +395,7 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
       logical, dimension(:), allocatable :: lencounter
       integer(I2B), dimension(npl) :: vplshift_min, vplshift_max
       integer(I2B), dimension(ntp) :: vtpshift_min, vtpshift_max
-      real(DP), dimension(ntp) :: renctp
+      real(DP), dimension(ntp) :: renctp 
 
       ! If this is the first time through, build the index lists
       if ((ntp == 0) .or. (npl == 0)) return
@@ -406,9 +406,11 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
          call boundingbox%setup(ntot, ntot_last)
          ntot_last = ntot
       end if
+
+      renctp(:) = 0.0_DP
       
       !$omp parallel do default(private) schedule(static) &
-      !$omp shared(xpl, xtp, vpl, vtp, renc, boundingbox) &
+      !$omp shared(xpl, xtp, vpl, vtp, rencpl, renctp, boundingbox) &
       !$omp firstprivate(dt, npl, ntp, ntot)
       do dim = 1, SWEEPDIM
          where(vpl(dim,1:npl) < 0.0_DP)
@@ -427,14 +429,14 @@ subroutine encounter_check_all_sort_and_sweep_pltp(npl, ntp, xpl, vpl, xtp, vtp,
             vtpshift_max(1:ntp) = 1
          end where
 
-         call boundingbox%aabb(dim)%sort(ntot, [xpl(dim,1:npl) - renc(1:npl) + vplshift_min(1:npl) * vpl(dim,1:npl) * dt, &
-                                                xtp(dim,1:ntp)               + vtpshift_min(1:ntp) * vtp(dim,1:ntp) * dt, &
-                                                xpl(dim,1:npl) + renc(1:npl) + vplshift_max(1:npl) * vpl(dim,1:npl) * dt, &
-                                                xtp(dim,1:ntp)               + vtpshift_max(1:ntp) * vtp(dim,1:ntp) * dt])
+         call boundingbox%aabb(dim)%sort(ntot, [xpl(dim,1:npl) - rencpl(1:npl) + vplshift_min(1:npl) * vpl(dim,1:npl) * dt, &
+                                                xtp(dim,1:ntp) - renctp(1:ntp) + vtpshift_min(1:ntp) * vtp(dim,1:ntp) * dt, &
+                                                xpl(dim,1:npl) + rencpl(1:npl) + vplshift_max(1:npl) * vpl(dim,1:npl) * dt, &
+                                                xtp(dim,1:ntp) + renctp(1:ntp) + vtpshift_max(1:ntp) * vtp(dim,1:ntp) * dt])
       end do
       !$omp end parallel do
 
-      call boundingbox%sweep(npl, ntp, xpl, vpl, xtp, vtp, renc, renctp, dt, nenc, index1, index2, lvdotr) 
+      call boundingbox%sweep(npl, ntp, xpl, vpl, xtp, vtp, rencpl, renctp, dt, nenc, index1, index2, lvdotr) 
 
       return
    end subroutine encounter_check_all_sort_and_sweep_pltp