diff --git a/examples/hugoniostat/in.nphug b/examples/hugoniostat/in.nphug
index 38cc5b7094..a41c38d2b1 100644
--- a/examples/hugoniostat/in.nphug
+++ b/examples/hugoniostat/in.nphug
@@ -1,6 +1,16 @@
-# This script reproduces the damped and undamped
-# stress trajectories in Fig. 1 in
+# This script reproduces stress trajectories from Fig. 1 in
 # Ravelo, Holian, Germann, and Lomdahl, PRB 70 014103 (2004)
+#
+# Three thermostatting scenarios are visited: undamped (nodrag), 
+# damped (drag) and Nose-Hoover chain (nhchains).
+#
+# The axial and shear stress trajectories are printed to the
+# file "stress_vs_t.dat". For the damped case, the original figure
+# seems to be a plot of 2*tau, rather than tau.
+#
+# The script also demonstrates how to 
+# orient a crystal along <110>,
+# and how to use the lj/cubic pair style. 
 
 units           lj
 boundary        p p p
@@ -24,6 +34,8 @@ create_atoms   1 box
 pair_style lj/cubic
 pair_coeff * * 1.0 0.8908987
 
+# Relax box dimensions
+
 fix             3 all box/relax aniso 0.0 vmax 1.0e-4 nreset 100
 
 thermo          100
@@ -51,7 +63,7 @@ reset_timestep 0
 
 # Pzz = 40.0, drag/damping term off
 
-fix myhug all nphug temp 1.0 1.0 1.0 z 40.0 40.0 70.0 drag 0.0 tchain 1 pchain 0 
+fix myhug all nphug temp 1.0 1.0 10.0 z 40.0 40.0 70.0 drag 0.0 tchain 1 pchain 0 
 
 # Specify reference state from paper, times 1000 atoms
 
@@ -67,7 +79,7 @@ variable dele  equal f_myhug[1] # energy delta [temperature]
 variable us    equal f_myhug[2] # shock velocity [distance/time]
 variable up    equal f_myhug[3] # particle velocity [distance/time]
 variable pzz   equal pzz  # axial stress
-variable tau equal (pzz-0.5*(pxx+pyy)) # shear stress
+variable tau equal 0.5*(pzz-0.5*(pxx+pyy)) # shear stress
 variable time equal dt*step
 
 thermo          10
@@ -107,13 +119,13 @@ variable dele  equal f_myhug[1] # energy delta [temperature]
 variable us    equal f_myhug[2] # shock velocity [distance/time]
 variable up    equal f_myhug[3] # particle velocity [distance/time]
 variable pzz   equal pzz  # axial stress
-variable tau equal (pzz-0.5*(pxx+pyy)) # shear stress
+variable tau equal 0.5*(pzz-0.5*(pxx+pyy)) # shear stress
 variable time equal dt*step
 
 thermo          10
 thermo_style custom step temp ke epair etotal pzz v_tau lz f_myhug v_dele v_us v_up
 
-fix stress all print 10 "${time} ${pzz} ${tau} " screen no append stress_vs_t.dat title '#time pzz tau (no drag)'
+fix stress all print 10 "${time} ${pzz} ${tau} " screen no append stress_vs_t.dat title '#time pzz tau (with drag)'
 
 run		10000
 
@@ -147,13 +159,13 @@ variable dele  equal f_myhug[1] # energy delta [temperature]
 variable us    equal f_myhug[2] # shock velocity [distance/time]
 variable up    equal f_myhug[3] # particle velocity [distance/time]
 variable pzz   equal pzz  # axial stress
-variable tau equal (pzz-0.5*(pxx+pyy)) # shear stress
+variable tau equal 0.5*(pzz-0.5*(pxx+pyy)) # shear stress
 variable time equal dt*step
 
 thermo          10
 thermo_style custom step temp ke epair etotal pzz v_tau lz f_myhug v_dele v_us v_up
 
-fix stress all print 10 "${time} ${pzz} ${tau} " screen no append stress_vs_t.dat title '#time pzz tau (no drag)'
+fix stress all print 10 "${time} ${pzz} ${tau} " screen no append stress_vs_t.dat title '#time pzz tau (Nose-Hoover chain)'
 
 run		10000