diff --git a/src/Makefile.am b/src/Makefile.am
index 65980089..9e40e222 100755
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,9 +1,13 @@
 bin_PROGRAMS = CTEM 
 #ifort optimized flags
-#AM_FCFLAGS =  -O3 -qopenmp -parallel -xHost -ipo -assume byterecl -m64 -heap-arrays -FR 
-AM_FCFLAGS =  -O3 -qopenmp -parallel -assume byterecl -m64 -heap-arrays -FR 
+SIMDVEC = -simd -xhost -align all -assume contiguous_assumed_shape -vecabi=cmdtarget -fp-model no-except -fma
+PAR = -qopenmp -parallel  
+HEAPARR = -heap-arrays 
+OPTREPORT = -qopt-report=5 
+IPRODUCTION = -g -traceback -no-wrap-margin -assume byterecl -O3 -qopt-prefetch=0 -sox $(PAR) $(SIMDVEC) $(HEAPARR)
+AM_FCFLAGS =  $(IPRODUCTION) $(OPTREPORT)
 #ifort debug flags
-#AM_FCFLAGS = -O0 -p -g -debug all -traceback -CB -assume byterecl -m64 -heap-arrays -FR
+#AM_FCFLAGS = -O0 -p -g -debug all -traceback -CB -assume byterecl -m64 -heap-arrays -FR $(PAR) $(SIMDVEC)
 
 #gfortran optimized flags
 #AM_FCFLAGS =  -O3 -fopenmp -ffree-form  -g -fbounds-check -fbacktrace
diff --git a/src/crater/crater_realistic_topography.f90 b/src/crater/crater_realistic_topography.f90
index a34c0f98..d40806da 100644
--- a/src/crater/crater_realistic_topography.f90
+++ b/src/crater/crater_realistic_topography.f90
@@ -96,11 +96,11 @@ subroutine ejecta_texture(user,surf,crater,deltaMtot,inc,ejecta_dem)
       real(DP),dimension(-inc:inc,-inc:inc),intent(inout) :: ejecta_dem
       end subroutine ejecta_texture
 
-      subroutine crater_realistic_slope_texture(user,critical,inc,critarray)
+      subroutine crater_realistic_slope_texture(user,critical_value,inc,critarray)
       use module_globals
       implicit none
       type(usertype),intent(in) :: user
-      real(DP),intent(in) :: critical
+      real(DP),intent(in) :: critical_value
       integer(I4B),intent(in) :: inc
       real(DP),dimension(-inc:inc,-inc:inc),intent(out) :: critarray
       end subroutine crater_realistic_slope_texture
@@ -741,7 +741,7 @@ subroutine ejecta_texture(user,surf,crater,deltaMtot,inc,ejecta_dem)
 end subroutine ejecta_texture
 
 
-subroutine crater_realistic_slope_texture(user,critical,inc,critarray)
+subroutine crater_realistic_slope_texture(user,critical_value,inc,critarray)
    ! Adds noise to the critical slope to give texture to regions that undergo slope collapse
    use module_globals
    use module_util
@@ -750,7 +750,7 @@ subroutine crater_realistic_slope_texture(user,critical,inc,critarray)
 
    ! Arguments
    type(usertype),intent(in) :: user
-   real(DP),intent(in) :: critical
+   real(DP),intent(in) :: critical_value
    integer(I4B),intent(in) :: inc
    real(DP),dimension(-inc:inc,-inc:inc),intent(out) :: critarray
 
@@ -786,7 +786,7 @@ subroutine crater_realistic_slope_texture(user,critical,inc,critarray)
                                               xynoise * ybar + offset * rn(2)) * znoise
          end do
          
-         critarray(i,j) = max(critical * (1.0_DP + noise),0.0_DP)
+         critarray(i,j) = max(critical_value * (1.0_DP + noise),0.0_DP)
       end do
    end do
 
diff --git a/src/crater/module_crater.f90 b/src/crater/module_crater.f90
index 68cb77db..b946c25b 100644
--- a/src/crater/module_crater.f90
+++ b/src/crater/module_crater.f90
@@ -209,14 +209,14 @@ end subroutine crater_tally_observed
    end interface
 
    interface
-      subroutine crater_slope_collapse(user,surf,crater,domain,critical,deltaMtot)
+      subroutine crater_slope_collapse(user,surf,crater,domain,critical_value,deltaMtot)
       use module_globals
       implicit none
       type(usertype),intent(in) :: user
       type(surftype),dimension(:,:),intent(inout) :: surf
       type(cratertype),intent(inout) :: crater
       type(domaintype),intent(in) :: domain
-      real(DP),intent(in) :: critical
+      real(DP),intent(in) :: critical_value
       real(DP),intent(inout) :: deltaMtot
       end subroutine crater_slope_collapse
    end interface
diff --git a/src/util/module_util.f90 b/src/util/module_util.f90
index 34cbecb7..eb0236e8 100644
--- a/src/util/module_util.f90
+++ b/src/util/module_util.f90
@@ -165,7 +165,7 @@ end subroutine util_search_int
 end interface util_search
 
 interface util_periodic
-   subroutine util_periodic(x,y,side)
+   pure subroutine util_periodic(x,y,side)
    use module_globals
    implicit none
    integer(I4B),intent(inout) :: x,y
diff --git a/src/util/util_periodic.f90 b/src/util/util_periodic.f90
index 40387f64..c2a4ea44 100644
--- a/src/util/util_periodic.f90
+++ b/src/util/util_periodic.f90
@@ -18,7 +18,7 @@
 !  Notes       :  
 !
 !**********************************************************************************************************************************
-subroutine util_periodic(x,y,side)
+pure subroutine util_periodic(x,y,side)
 use module_globals
 use module_util, EXCEPT_THIS_ONE => util_periodic
 implicit none