diff --git a/src/fix_npt_sphere.cpp b/src/fix_npt_sphere.cpp
index bdeb0a5ee7..7d1f231058 100644
--- a/src/fix_npt_sphere.cpp
+++ b/src/fix_npt_sphere.cpp
@@ -157,7 +157,7 @@ void FixNPTSphere::initial_integrate(int vflag)
   int ntypes = atom->ntypes;
   double **shape = atom->shape;
   for (int i = 1; i <= ntypes; i++)
-    dttype[i] = dtfrotate / (0.25*shape[i][0]*shape[i][0]*mass[i]);
+    dttype[i] = dtfrotate / (shape[i][0]*shape[i][0]*mass[i]);
 
   // update angular momentum by 1/2 step
   // update quaternion a full step via Richardson iteration
@@ -206,7 +206,7 @@ void FixNPTSphere::final_integrate()
   int ntypes = atom->ntypes;
   double **shape = atom->shape;
   for (int i = 1; i <= ntypes; i++)
-    dttype[i] = dtfrotate / (0.25*shape[i][0]*shape[i][0]*mass[i]);
+    dttype[i] = dtfrotate / (shape[i][0]*shape[i][0]*mass[i]);
 
   if (which == NOBIAS) {
     for (i = 0; i < nlocal; i++) {
diff --git a/src/fix_nve_sphere.cpp b/src/fix_nve_sphere.cpp
index a049332e75..41650c3ad3 100644
--- a/src/fix_nve_sphere.cpp
+++ b/src/fix_nve_sphere.cpp
@@ -131,7 +131,7 @@ void FixNVESphere::initial_integrate(int vflag)
     double **shape = atom->shape;
     int ntypes = atom->ntypes;
     for (int i = 1; i <= ntypes; i++)
-      dttype[i] = dtfrotate / (0.25*shape[i][0]*shape[i][0]*mass[i]);
+      dttype[i] = dtfrotate / (shape[i][0]*shape[i][0]*mass[i]);
   }
 
   // update v,x,omega for all particles
@@ -225,7 +225,7 @@ void FixNVESphere::final_integrate()
     double **shape = atom->shape;
     int ntypes = atom->ntypes;
     for (int i = 1; i <= ntypes; i++)
-      dttype[i] = dtfrotate / (0.25*shape[i][0]*shape[i][0]*mass[i]);
+      dttype[i] = dtfrotate / (shape[i][0]*shape[i][0]*mass[i]);
   }
 
   if (mass) {
diff --git a/src/fix_nvt_sphere.cpp b/src/fix_nvt_sphere.cpp
index b86d27ee85..4c2b753527 100644
--- a/src/fix_nvt_sphere.cpp
+++ b/src/fix_nvt_sphere.cpp
@@ -102,7 +102,7 @@ void FixNVTSphere::initial_integrate(int vflag)
   int ntypes = atom->ntypes;
   double **shape = atom->shape;
   for (int i = 1; i <= ntypes; i++)
-    dttype[i] = dtfrotate / (0.25*shape[i][0]*shape[i][0]*mass[i]);
+    dttype[i] = dtfrotate / (shape[i][0]*shape[i][0]*mass[i]);
 
   if (which == NOBIAS) {
     for (int i = 0; i < nlocal; i++) {
@@ -173,7 +173,7 @@ void FixNVTSphere::final_integrate()
   int ntypes = atom->ntypes;
   double **shape = atom->shape;
   for (int i = 1; i <= ntypes; i++)
-    dttype[i] = dtfrotate / (0.25*shape[i][0]*shape[i][0]*mass[i]);
+    dttype[i] = dtfrotate / (shape[i][0]*shape[i][0]*mass[i]);
 
   if (which == NOBIAS) {
     for (int i = 0; i < nlocal; i++) {
diff --git a/src/pair.cpp b/src/pair.cpp
index 9bb99bea32..9d4a2ea94d 100644
--- a/src/pair.cpp
+++ b/src/pair.cpp
@@ -699,17 +699,43 @@ void Pair::virial_compute()
 {
   double **x = atom->x;
   double **f = atom->f;
-  int nall = atom->nlocal + atom->nghost;
 
-  // sum over own & ghost atoms
+  // sum over force on all particles including ghosts
 
-  for (int i = 0; i < nall; i++) {
-    virial[0] += f[i][0]*x[i][0];
-    virial[1] += f[i][1]*x[i][1];
-    virial[2] += f[i][2]*x[i][2];
-    virial[3] += f[i][1]*x[i][0];
-    virial[4] += f[i][2]*x[i][0];
-    virial[5] += f[i][2]*x[i][1];
+  if (neighbor->includegroup == 0) {
+    int nall = atom->nlocal + atom->nghost;
+    for (int i = 0; i < nall; i++) {
+      virial[0] += f[i][0]*x[i][0];
+      virial[1] += f[i][1]*x[i][1];
+      virial[2] += f[i][2]*x[i][2];
+      virial[3] += f[i][1]*x[i][0];
+      virial[4] += f[i][2]*x[i][0];
+      virial[5] += f[i][2]*x[i][1];
+    }
+
+  // neighbor includegroup flag is set
+  // sum over force on initial nfirst particles and ghosts
+
+  } else {
+    int nall = atom->nfirst;
+    for (int i = 0; i < nall; i++) {
+      virial[0] += f[i][0]*x[i][0];
+      virial[1] += f[i][1]*x[i][1];
+      virial[2] += f[i][2]*x[i][2];
+      virial[3] += f[i][1]*x[i][0];
+      virial[4] += f[i][2]*x[i][0];
+      virial[5] += f[i][2]*x[i][1];
+    }
+
+    nall = atom->nlocal + atom->nghost;
+    for (int i = atom->nlocal; i < nall; i++) {
+      virial[0] += f[i][0]*x[i][0];
+      virial[1] += f[i][1]*x[i][1];
+      virial[2] += f[i][2]*x[i][2];
+      virial[3] += f[i][1]*x[i][0];
+      virial[4] += f[i][2]*x[i][0];
+      virial[5] += f[i][2]*x[i][1];
+    }
   }
 }