diff --git a/src/RIGID/fix_rigid_nh.cpp b/src/RIGID/fix_rigid_nh.cpp
index 6fb2bd7a94..4dec04370e 100644
--- a/src/RIGID/fix_rigid_nh.cpp
+++ b/src/RIGID/fix_rigid_nh.cpp
@@ -234,8 +234,6 @@ void FixRigidNH::init()
   }
 
   g_f = nf_t + nf_r;
-  onednft = 1.0 + (double)(dimension) / (double)g_f;
-  onednfr = (double) (dimension) / (double)g_f;
 
   // see Table 1 in Kamberaj et al
 
@@ -719,6 +717,8 @@ void FixRigidNH::final_integrate()
 
 void FixRigidNH::nhc_temp_integrate()
 {
+  if (g_f == 0) return;
+
   int i,j,k;
   double kt,gfkt_t,gfkt_r,tmp,ms,s,s2;
 
@@ -1063,6 +1063,8 @@ void FixRigidNH::compute_press_target()
 
 void FixRigidNH::nh_epsilon_dot()
 {
+  if (g_f == 0) return;
+
   int i;
   double volume,scale,f_epsilon;
 
diff --git a/src/RIGID/fix_rigid_nh.h b/src/RIGID/fix_rigid_nh.h
index a8850413eb..10ad9b24fb 100644
--- a/src/RIGID/fix_rigid_nh.h
+++ b/src/RIGID/fix_rigid_nh.h
@@ -38,8 +38,6 @@ class FixRigidNH : public FixRigid {
   double boltz,nktv2p,mvv2e;          // boltzman constant, conversion factors
 
   int nf_t,nf_r;                      // trans/rot degrees of freedom
-  double onednft,onednfr;             // factors 1 + dimension/trans(rot)
-                                      //   degrees of freedom
   double *w,*wdti1,*wdti2,*wdti4;     // Yoshida-Suzuki coefficients
   double *q_t,*q_r;                   // trans/rot thermostat masses
   double *eta_t,*eta_r;               // trans/rot thermostat positions