From c571a4b12629699250f8c19c3a95f6ba2b15c6eb Mon Sep 17 00:00:00 2001
From: Adam Nelson <nelsonag@umich.edu>
Date: Sat, 7 Nov 2015 14:23:20 -0500
Subject: [PATCH] Got cmfd working, not sure about with feedback just yet

---
 examples/xml/multigroup/c5g7/2d/cmfd.xml     |  6 +++---
 examples/xml/multigroup/c5g7/2d/settings.xml |  4 ++--
 src/tally.F90                                | 15 ++++++++++++---
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/examples/xml/multigroup/c5g7/2d/cmfd.xml b/examples/xml/multigroup/c5g7/2d/cmfd.xml
index 22b1e9042..1b1e523b1 100644
--- a/examples/xml/multigroup/c5g7/2d/cmfd.xml
+++ b/examples/xml/multigroup/c5g7/2d/cmfd.xml
@@ -1,9 +1,9 @@
 <?xml version="1.0"?>
 
 <cmfd>
-  <begin>1</begin>
-  <feedback>true</feedback>
-  <solver>jfnk</solver>
+  <begin>2</begin>
+  <feedback>false</feedback>
+  <solver>power</solver>
   <mesh>
     <lower_left> 0.0 0.0 -100.0</lower_left>
     <upper_right> 64.26 64.26 100.0</upper_right>
diff --git a/examples/xml/multigroup/c5g7/2d/settings.xml b/examples/xml/multigroup/c5g7/2d/settings.xml
index 189adc6c9..faed7cd7f 100644
--- a/examples/xml/multigroup/c5g7/2d/settings.xml
+++ b/examples/xml/multigroup/c5g7/2d/settings.xml
@@ -33,7 +33,7 @@
 
   <!-- Establish statepoints to aid in examining convergence -->
   <state_point>
-    <interval> 2000 </interval>
+    <interval> 2500 </interval>
     <source_write>true</source_write>
   </state_point>
 
@@ -43,7 +43,7 @@
     <tallies>true</tallies>
   </output>
 
-  <run_cmfd>false</run_cmfd>
+  <run_cmfd>true</run_cmfd>
 
   <cross_sections>../data.xml</cross_sections>
 
diff --git a/src/tally.F90 b/src/tally.F90
index 7ad701b16..6b3e7a793 100644
--- a/src/tally.F90
+++ b/src/tally.F90
@@ -966,8 +966,11 @@ contains
         ! For scattering production, we need to use the pre-collision
         ! weight times the multiplicity as the estimate for the number of
         ! neutrons exiting a reaction with neutrons in the exit channel
-        score = p % wgt * nuc % get_xs(p % g, 'f_mu', p % last_g, &
+        score = p % wgt
+        if (i_nuclide > 0) then
+          score = score * nuc % get_xs(p % g, 'f_mu', p % last_g, &
                                        p % last_uvw, p % mu)
+        end if
 
 
       case (SCORE_NU_SCATTER_PN)
@@ -980,8 +983,11 @@ contains
         ! For scattering production, we need to use the pre-collision
         ! weight times the multiplicity as the estimate for the number of
         ! neutrons exiting a reaction with neutrons in the exit channel
-        score = p % wgt * nuc % get_xs(p % g, 'f_mu', p % last_g, &
+        score = p % wgt
+        if (i_nuclide > 0) then
+          score = score * nuc % get_xs(p % g, 'f_mu', p % last_g, &
                                        p % last_uvw, p % mu)
+        end if
 
 
       case (SCORE_NU_SCATTER_YN)
@@ -994,8 +1000,11 @@ contains
         ! For scattering production, we need to use the pre-collision
         ! weight times the multiplicity as the estimate for the number of
         ! neutrons exiting a reaction with neutrons in the exit channel
-        score = p % wgt * nuc % get_xs(p % g, 'f_mu', p % last_g, &
+        score = p % wgt
+        if (i_nuclide > 0) then
+          score = score * nuc % get_xs(p % g, 'f_mu', p % last_g, &
                                        p % last_uvw, p % mu)
+        end if
 
 
       case (SCORE_TRANSPORT)