diff -Naur lammps-22Jun09/doc/fix_freeze.html lammps-23Jun09/doc/fix_freeze.html
--- lammps-22Jun09/doc/fix_freeze.html	2007-10-10 16:28:11.000000000 -0600
+++ lammps-23Jun09/doc/fix_freeze.html	2009-06-22 14:49:14.000000000 -0600
@@ -25,17 +25,27 @@
 <P><B>Description:</B>
 </P>
 <P>Zero out the force and torque on a granular particle.  This is useful
-for preventing certain particles from moving in a simulation.
+for preventing certain particles from moving in a simulation.  The
+<A HREF = "pair_gran.html">granular pair styles</A> also detect if this fix has been
+defined and compute interactions between frozen and non-frozen
+particles appropriately, as if the frozen particle has infinite mass.
 </P>
 <P><B>Restart, fix_modify, output, run start/stop, minimize info:</B>
 </P>
 <P>No information about this fix is written to <A HREF = "restart.html">binary restart
 files</A>.  None of the <A HREF = "fix_modify.html">fix_modify</A> options
-are relevant to this fix.  No global scalar or vector or per-atom
-quantities are stored by this fix for access by various <A HREF = "Section_howto.html#4_15">output
-commands</A>.  No parameter of this fix can be
-used with the <I>start/stop</I> keywords of the <A HREF = "run.html">run</A> command.
-This fix is not invoked during <A HREF = "minimize.html">energy minimization</A>.
+are relevant to this fix.
+</P>
+<P>This fix computes a 3-vector of forces, which can be accessed by
+various <A HREF = "Section_howto.html#4_15">output commands</A>.  This is the total
+force on the group of atoms before the forces on individual atoms are
+changed by the fix.  The vector values calculated by this fix are
+"extensive", meaning they scale with the number of atoms in the
+simulation.
+</P>
+<P>No parameter of this fix can be used with the <I>start/stop</I> keywords of
+the <A HREF = "run.html">run</A> command.  This fix is not invoked during <A HREF = "minimize.html">energy
+minimization</A>.
 </P>
 <P><B>Restrictions:</B>
 </P>
@@ -44,9 +54,9 @@
 LAMMPS</A> section for more info.
 </P>
 <P>There can only be a single freeze fix defined.  This is because other
-parts of the code (pair potentials, thermodynamics, etc) treat frozen
-particles differently and need to be able to reference a single group
-to which this fix is applied.
+the <A HREF = "pair_gran.html">granular pair styles</A> treat frozen particles
+differently and need to be able to reference a single group to which
+this fix is applied.
 </P>
 <P><B>Related commands:</B> none
 </P>
diff -Naur lammps-22Jun09/doc/fix_freeze.txt lammps-23Jun09/doc/fix_freeze.txt
--- lammps-22Jun09/doc/fix_freeze.txt	2007-10-10 16:28:11.000000000 -0600
+++ lammps-23Jun09/doc/fix_freeze.txt	2009-06-22 14:49:14.000000000 -0600
@@ -22,17 +22,27 @@
 [Description:]
 
 Zero out the force and torque on a granular particle.  This is useful
-for preventing certain particles from moving in a simulation.
+for preventing certain particles from moving in a simulation.  The
+"granular pair styles"_pair_gran.html also detect if this fix has been
+defined and compute interactions between frozen and non-frozen
+particles appropriately, as if the frozen particle has infinite mass.
 
 [Restart, fix_modify, output, run start/stop, minimize info:]
 
 No information about this fix is written to "binary restart
 files"_restart.html.  None of the "fix_modify"_fix_modify.html options
-are relevant to this fix.  No global scalar or vector or per-atom
-quantities are stored by this fix for access by various "output
-commands"_Section_howto.html#4_15.  No parameter of this fix can be
-used with the {start/stop} keywords of the "run"_run.html command.
-This fix is not invoked during "energy minimization"_minimize.html.
+are relevant to this fix.
+
+This fix computes a 3-vector of forces, which can be accessed by
+various "output commands"_Section_howto.html#4_15.  This is the total
+force on the group of atoms before the forces on individual atoms are
+changed by the fix.  The vector values calculated by this fix are
+"extensive", meaning they scale with the number of atoms in the
+simulation.
+
+No parameter of this fix can be used with the {start/stop} keywords of
+the "run"_run.html command.  This fix is not invoked during "energy
+minimization"_minimize.html.
 
 [Restrictions:]
 
@@ -41,9 +51,9 @@
 LAMMPS"_Section_start.html#2_3 section for more info.
 
 There can only be a single freeze fix defined.  This is because other
-parts of the code (pair potentials, thermodynamics, etc) treat frozen
-particles differently and need to be able to reference a single group
-to which this fix is applied.
+the "granular pair styles"_pair_gran.html treat frozen particles
+differently and need to be able to reference a single group to which
+this fix is applied.
 
 [Related commands:] none
 
diff -Naur lammps-22Jun09/doc/pair_reax.html lammps-23Jun09/doc/pair_reax.html
--- lammps-22Jun09/doc/pair_reax.html	2009-06-03 13:59:51.000000000 -0600
+++ lammps-23Jun09/doc/pair_reax.html	2009-06-22 14:49:58.000000000 -0600
@@ -39,7 +39,8 @@
 <P>LAMMPS provides a ReaxFF potential file in its potentials dir, namely
 potentials/ffield.reax.  Its format is identical to that used by van
 Duin and co-workers.  It contains parameterizations for the following
-elements: C, H, O, N, S, and Si.  You can use your another file in
+elements: C, H, O, N, S (Si has been temporarily removed).
+You can use another file in
 place of it, and ReaxFF files with parameterizations for other
 elements or for specific chemical systems may be available elsewhere.
 </P>
diff -Naur lammps-22Jun09/src/GRANULAR/fix_freeze.cpp lammps-23Jun09/src/GRANULAR/fix_freeze.cpp
--- lammps-22Jun09/src/GRANULAR/fix_freeze.cpp	2009-04-15 07:05:53.000000000 -0600
+++ lammps-23Jun09/src/GRANULAR/fix_freeze.cpp	2009-06-22 14:48:55.000000000 -0600
@@ -31,6 +31,14 @@
 
   if (!atom->torque_flag)
     error->all("Fix freeze requires atom attribute torque");
+
+  vector_flag = 1;
+  size_vector = 3;
+  scalar_vector_freq = 1;
+  extvector = 1;
+
+  force_flag = 0;
+  foriginal[0] = foriginal[1] = foriginal[2] = 0.0;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -82,8 +90,14 @@
   int nlocal = atom->nlocal;
   if (igroup == atom->firstgroup) nlocal = atom->nfirst;
 
+  foriginal[0] = foriginal[1] = foriginal[2] = 0.0;
+  force_flag = 0;
+
   for (int i = 0; i < nlocal; i++)
     if (mask[i] & groupbit) {
+      foriginal[0] += f[i][0];
+      foriginal[1] += f[i][1];
+      foriginal[2] += f[i][2];
       f[i][0] = 0.0;
       f[i][1] = 0.0;
       f[i][2] = 0.0;
@@ -100,3 +114,17 @@
   post_force(vflag);
 }
 
+/* ----------------------------------------------------------------------
+   return components of total force on fix group before force was changed
+------------------------------------------------------------------------- */
+
+double FixFreeze::compute_vector(int n)
+{
+  // only sum across procs one time
+
+  if (force_flag == 0) {
+    MPI_Allreduce(foriginal,foriginal_all,3,MPI_DOUBLE,MPI_SUM,world);
+    force_flag = 1;
+  }
+  return foriginal_all[n];
+}
diff -Naur lammps-22Jun09/src/GRANULAR/fix_freeze.h lammps-23Jun09/src/GRANULAR/fix_freeze.h
--- lammps-22Jun09/src/GRANULAR/fix_freeze.h	2009-04-15 07:05:53.000000000 -0600
+++ lammps-23Jun09/src/GRANULAR/fix_freeze.h	2009-06-22 14:48:55.000000000 -0600
@@ -26,6 +26,11 @@
   void setup(int);
   void post_force(int);
   void post_force_respa(int, int, int);
+  double compute_vector(int);
+
+ private:
+  int force_flag;
+  double foriginal[3],foriginal_all[3];
 };
 
 }