diff -Naur lammps-21Nov08/src/min_cg.cpp lammps-24Nov08/src/min_cg.cpp
--- lammps-21Nov08/src/min_cg.cpp	2008-11-06 08:17:59.000000000 -0700
+++ lammps-24Nov08/src/min_cg.cpp	2008-11-24 08:02:29.000000000 -0700
@@ -148,6 +148,7 @@
 	
   einitial = ecurrent;
 
+  f = NULL;
   if (ndof) f = atom->f[0];
   tmp = 0.0;
   for (int i = 0; i < ndof; i++) tmp += f[i]*f[i];
@@ -206,6 +207,7 @@
 	
   efinal = ecurrent;
 
+  f = NULL;
   if (ndof) f = atom->f[0];
   tmp = 0.0;
   for (int i = 0; i < ndof; i++) tmp += f[i]*f[i];
@@ -278,7 +280,7 @@
   double beta,gg,dot[2],dotall[2];
 
   double *f = NULL;
-  if (ndof) atom->f[0];
+  if (ndof) f = atom->f[0];
   for (i = 0; i < ndof; i++) h[i] = g[i] = f[i];
 
   dot[0] = 0.0;
diff -Naur lammps-21Nov08/src/min_sd.cpp lammps-24Nov08/src/min_sd.cpp
--- lammps-21Nov08/src/min_sd.cpp	2008-04-16 18:06:14.000000000 -0600
+++ lammps-24Nov08/src/min_sd.cpp	2008-11-24 08:02:29.000000000 -0700
@@ -38,7 +38,8 @@
   int i,fail,ntimestep;
   double dot,dotall;
 
-  double *f = atom->f[0];
+  double *f = NULL;
+  if (ndof) f = atom->f[0];
   for (i = 0; i < ndof; i++) h[i] = f[i];
 
   neval = 0;
@@ -65,7 +66,7 @@
 
     // force tolerance criterion
 
-    f = atom->f[0];
+    if (ndof) f = atom->f[0];
     dot = 0.0;
     for (i = 0; i < ndof; i++) dot += f[i]*f[i];
     MPI_Allreduce(&dot,&dotall,1,MPI_DOUBLE,MPI_SUM,world);