From 6a4a7506cfb316c8e9e746a0161cf1e4571fc575 Mon Sep 17 00:00:00 2001
From: sjplimp <sjplimp@f3b2605a-c512-4ea7-a41b-209d697bcdaa>
Date: Mon, 2 Jun 2014 16:04:35 +0000
Subject: [PATCH] git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@12056
 f3b2605a-c512-4ea7-a41b-209d697bcdaa

---
 src/variable.cpp | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/variable.cpp b/src/variable.cpp
index 9d78631229..78048a8c10 100644
--- a/src/variable.cpp
+++ b/src/variable.cpp
@@ -3482,7 +3482,7 @@ int Variable::special_function(char *word, char *contents, Tree **tree,
    id = positive global ID of atom, converted to local index
    push result onto tree or arg stack
    customize by adding an atom vector:
-     id,mass,type,mol,x,y,z,vx,vy,vz,fx,fy,fz
+     id,mass,type,mol,x,y,z,vx,vy,vz,fx,fy,fz,q
 ------------------------------------------------------------------------- */
 
 void Variable::peratom2global(int flag, char *word,
@@ -3520,7 +3520,11 @@ void Variable::peratom2global(int flag, char *word,
       else if (strcmp(word,"fx") == 0) mine = atom->f[index][0];
       else if (strcmp(word,"fy") == 0) mine = atom->f[index][1];
       else if (strcmp(word,"fz") == 0) mine = atom->f[index][2];
-
+      else if (strcmp(word,"q") == 0) {
+        if (!atom->q_flag) 
+          error->one(FLERR,"Variable uses atom property that isn't allocated");
+        mine = atom->q[index];
+      }
       else error->one(FLERR,"Invalid atom vector in variable formula");
 
     } else mine = vector[index*nstride];
@@ -3543,7 +3547,7 @@ void Variable::peratom2global(int flag, char *word,
    check if word matches an atom vector
    return 1 if yes, else 0
    customize by adding an atom vector:
-     id,mass,type,mol,x,y,z,vx,vy,vz,fx,fy,fz
+     id,mass,type,mol,x,y,z,vx,vy,vz,fx,fy,fz,q
 ------------------------------------------------------------------------- */
 
 int Variable::is_atom_vector(char *word)
@@ -3561,6 +3565,7 @@ int Variable::is_atom_vector(char *word)
   if (strcmp(word,"fx") == 0) return 1;
   if (strcmp(word,"fy") == 0) return 1;
   if (strcmp(word,"fz") == 0) return 1;
+  if (strcmp(word,"q") == 0) return 1;
   return 0;
 }
 
@@ -3569,7 +3574,7 @@ int Variable::is_atom_vector(char *word)
    push result onto tree
    word = atom vector
    customize by adding an atom vector:
-     id,mass,type,mol,x,y,z,vx,vy,vz,fx,fy,fz
+     id,mass,type,mol,x,y,z,vx,vy,vz,fx,fy,fz,q
 ------------------------------------------------------------------------- */
 
 void Variable::atom_vector(char *word, Tree **tree,
@@ -3631,6 +3636,11 @@ void Variable::atom_vector(char *word, Tree **tree,
   else if (strcmp(word,"fx") == 0) newtree->array = &atom->f[0][0];
   else if (strcmp(word,"fy") == 0) newtree->array = &atom->f[0][1];
   else if (strcmp(word,"fz") == 0) newtree->array = &atom->f[0][2];
+
+  else if (strcmp(word,"q") == 0) {
+    newtree->nstride = 1;
+    newtree->array = atom->q;
+  }
 }
 
 /* ----------------------------------------------------------------------