diff --git a/src/KSPACE/pppm.cpp b/src/KSPACE/pppm.cpp
index 8d89eca585..8dddc63686 100644
--- a/src/KSPACE/pppm.cpp
+++ b/src/KSPACE/pppm.cpp
@@ -198,7 +198,8 @@ void PPPM::init()
   while (order > 0) {
 
     if (iteration && me == 0)
-      error->warning("Reducing PPPM order b/c stencil extends beyond neighbor processor");
+      error->warning("Reducing PPPM order b/c stencil extends "
+		     "beyond neighbor processor");
     iteration++;
 
     set_grid();
diff --git a/src/dump_custom.cpp b/src/dump_custom.cpp
index 6d04a3933f..137759b061 100644
--- a/src/dump_custom.cpp
+++ b/src/dump_custom.cpp
@@ -39,6 +39,7 @@ enum{ID,MOL,TYPE,MASS,X,Y,Z,XS,YS,ZS,XU,YU,ZU,IX,IY,IZ,
        COMPUTE,FIX,VARIABLE};
 enum{LT,LE,GT,GE,EQ,NEQ};
 enum{INT,DOUBLE};
+enum{DUMMY0,INVOKED_SCALAR,INVOKED_VECTOR,DUMMMY3,INVOKED_PERATOM};
 
 /* ---------------------------------------------------------------------- */
 
@@ -267,15 +268,14 @@ int DumpCustom::count()
   }
 
   // invoke Computes for per-atom dump quantities
-  // only if not already invoked
 
   if (ncompute) {
     int ntimestep = update->ntimestep;
-    for (i = 0; i < ncompute; i++) {
-      if (compute[i]->invoked_peratom != ntimestep)
+    for (i = 0; i < ncompute; i++)
+      if (!(compute[i]->invoked_flag & INVOKED_PERATOM)) {
 	compute[i]->compute_peratom();
-      compute[i]->invoked_flag = 1;
-    }
+	compute[i]->invoked_flag |= INVOKED_PERATOM;
+      }
   }
 
   // evaluate atom-style Variables for per-atom dump quantities
diff --git a/src/fix_ave_atom.cpp b/src/fix_ave_atom.cpp
index 596cf38acb..f118f0badb 100644
--- a/src/fix_ave_atom.cpp
+++ b/src/fix_ave_atom.cpp
@@ -26,6 +26,7 @@
 using namespace LAMMPS_NS;
 
 enum{X,V,F,COMPUTE,FIX,VARIABLE};
+enum{DUMMY0,INVOKED_SCALAR,INVOKED_VECTOR,DUMMMY3,INVOKED_PERATOM};
 
 /* ---------------------------------------------------------------------- */
 
@@ -309,8 +310,10 @@ void FixAveAtom::end_of_step()
 
     } else if (which[m] == COMPUTE) {
       Compute *compute = modify->compute[n];
-      if (compute->invoked_peratom != ntimestep) compute->compute_peratom();
-      compute->invoked_flag = 1;
+      if (!(compute->invoked_flag & INVOKED_PERATOM)) {
+	compute->compute_peratom();
+	compute->invoked_flag |= INVOKED_PERATOM;
+      }
 
       if (j == 0) {
 	double *compute_scalar = compute->scalar_atom;
diff --git a/src/fix_ave_spatial.cpp b/src/fix_ave_spatial.cpp
index 753520361c..fd9c36cdad 100644
--- a/src/fix_ave_spatial.cpp
+++ b/src/fix_ave_spatial.cpp
@@ -36,6 +36,7 @@ enum{X,V,F,DENSITY_NUMBER,DENSITY_MASS,COMPUTE,FIX,VARIABLE};
 enum{SAMPLE,ALL};
 enum{BOX,LATTICE,REDUCED};
 enum{ONE,RUNNING,WINDOW};
+enum{DUMMY0,INVOKED_SCALAR,INVOKED_VECTOR,DUMMMY3,INVOKED_PERATOM};
 
 #define BIG 1000000000
 
@@ -622,8 +623,10 @@ void FixAveSpatial::end_of_step()
 
     } else if (which[m] == COMPUTE) {
       Compute *compute = modify->compute[n];
-      if (compute->invoked_peratom != ntimestep) compute->compute_peratom();
-      compute->invoked_flag = 1;
+      if (!(compute->invoked_flag & INVOKED_PERATOM)) {
+	compute->compute_peratom();
+	compute->invoked_flag |= INVOKED_PERATOM;
+      }
       double *scalar = compute->scalar_atom;
       double **vector = compute->vector_atom;
       int jm1 = j - 1;
diff --git a/src/fix_ave_time.cpp b/src/fix_ave_time.cpp
index e5eaa35e2e..97d45bda56 100644
--- a/src/fix_ave_time.cpp
+++ b/src/fix_ave_time.cpp
@@ -31,6 +31,7 @@ using namespace LAMMPS_NS;
 
 enum{COMPUTE,FIX,VARIABLE};
 enum{ONE,RUNNING,WINDOW};
+enum{DUMMY0,INVOKED_SCALAR,INVOKED_VECTOR,DUMMMY3,INVOKED_PERATOM};
 
 /* ---------------------------------------------------------------------- */
 
@@ -351,13 +352,17 @@ void FixAveTime::end_of_step()
       Compute *compute = modify->compute[m];
 
       if (argindex[i] == 0) {
-	if (compute->invoked_scalar == ntimestep) vector[i] += compute->scalar;
-	else vector[i] += compute->compute_scalar();
-	compute->invoked_flag = 1;
+	if (!(compute->invoked_flag & INVOKED_SCALAR)) {
+	  compute->compute_scalar();
+	  compute->invoked_flag |= INVOKED_SCALAR;
+	}
+	vector[i] += compute->compute_scalar();
       } else {
-	if (compute->invoked_vector != ntimestep) compute->compute_vector();
+	if (!(compute->invoked_flag & INVOKED_VECTOR)) {
+	  compute->compute_vector();
+	  compute->invoked_flag |= INVOKED_VECTOR;
+	}
 	vector[i] += compute->vector[argindex[i]-1];
-	compute->invoked_flag = 1;
       }
 
     // access fix fields, guaranteed to be ready
diff --git a/src/modify.cpp b/src/modify.cpp
index f6ff32c45b..a227bc4749 100644
--- a/src/modify.cpp
+++ b/src/modify.cpp
@@ -684,21 +684,22 @@ int Modify::find_compute(char *id)
 }
 
 /* ----------------------------------------------------------------------
-   loop only over computes that store invocation times
-   clear their invoked flag for this step
-   called before computes are invoked
+   clear invoked flag of all computes
+   called everywhere that computes are used, before computes are invoked
+   invoked flag used to avoid re-invoking same compute multiple times
+   and to flag computes that store invocation times as having been invoked
 ------------------------------------------------------------------------- */
 
 void Modify::clearstep_compute()
 {
-  for (int icompute = 0; icompute < n_timeflag; icompute++)
+  for (int icompute = 0; icompute < ncompute; icompute++)
     compute[list_timeflag[icompute]]->invoked_flag = 0;
 }
 
 /* ----------------------------------------------------------------------
-   loop only over computes that store invocation times
-   if its invoked flag set on this timestep, schedule the next invocation
-   called after computes are invoked
+   loop over computes that store invocation times
+   if its invoked flag set on this timestep, schedule next invocation
+   called everywhere that computes are used, after computes are invoked
 ------------------------------------------------------------------------- */
 
 void Modify::addstep_compute(int newstep)
@@ -709,8 +710,8 @@ void Modify::addstep_compute(int newstep)
 }
 
 /* ----------------------------------------------------------------------
-   loop over all computes
-   schedule the next invocation for those that store invocation times
+   loop over computes that store invocation times
+   schedule next invocation for all of them
    called when not sure what computes will be needed on newstep
 ------------------------------------------------------------------------- */
 
diff --git a/src/run.cpp b/src/run.cpp
index 8ececad10e..7eb539a971 100644
--- a/src/run.cpp
+++ b/src/run.cpp
@@ -195,7 +195,8 @@ void Run::command(int narg, char **arg)
       if (postflag || nleft <= nsteps) finish.end(1);
       else finish.end(0);
 
-      // command string may invoke computes so wrap with clear/add
+      // command string may invoke computes via command with variable
+      // so wrap with clearstep/addstep
 
       if (commandstr) {
 	modify->clearstep_compute();
diff --git a/src/style_meam.h b/src/style_meam.h
index 221a363f11..e69de29bb2 100644
--- a/src/style_meam.h
+++ b/src/style_meam.h
@@ -1,20 +0,0 @@
-/* ----------------------------------------------------------------------
-   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
-   http://lammps.sandia.gov, Sandia National Laboratories
-   Steve Plimpton, sjplimp@sandia.gov
-
-   Copyright (2003) Sandia Corporation.  Under the terms of Contract
-   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
-   certain rights in this software.  This software is distributed under 
-   the GNU General Public License.
-
-   See the README file in the top-level LAMMPS directory.
-------------------------------------------------------------------------- */
-
-#ifdef PairInclude
-#include "pair_meam.h"
-#endif
-
-#ifdef PairClass
-PairStyle(meam,PairMEAM)
-#endif
diff --git a/src/style_poems.h b/src/style_poems.h
index 0434d02bf8..e69de29bb2 100644
--- a/src/style_poems.h
+++ b/src/style_poems.h
@@ -1,20 +0,0 @@
-/* ----------------------------------------------------------------------
-   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
-   http://lammps.sandia.gov, Sandia National Laboratories
-   Steve Plimpton, sjplimp@sandia.gov
-
-   Copyright (2003) Sandia Corporation.  Under the terms of Contract
-   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
-   certain rights in this software.  This software is distributed under 
-   the GNU General Public License.
-
-   See the README file in the top-level LAMMPS directory.
-------------------------------------------------------------------------- */
-
-#ifdef FixInclude
-#include "fix_poems.h"
-#endif
-
-#ifdef FixClass
-FixStyle(poems,FixPOEMS)
-#endif
diff --git a/src/thermo.cpp b/src/thermo.cpp
index 59ad878a1f..d486b66092 100644
--- a/src/thermo.cpp
+++ b/src/thermo.cpp
@@ -53,6 +53,7 @@ using namespace LAMMPS_NS;
 enum{IGNORE,WARN,ERROR};           // same as write_restart.cpp
 enum{ONELINE,MULTILINE};
 enum{INT,FLOAT};
+enum{DUMMY0,INVOKED_SCALAR,INVOKED_VECTOR,DUMMMY3,INVOKED_PERATOM};
 
 #define MAXLINE 1024
 #define DELTA 8
@@ -268,16 +269,18 @@ void Thermo::compute(int flag)
   // invoke Compute methods needed for thermo keywords
   // which = 0 is global scalar, which = 1 is global vector
 
-  for (i = 0; i < ncompute; i++) {
+  for (i = 0; i < ncompute; i++)
     if (compute_which[i] == 0) {
-      if (computes[i]->invoked_scalar != ntimestep)
+      if (!(computes[i]->invoked_flag & INVOKED_SCALAR)) {
 	computes[i]->compute_scalar();
+	computes[i]->invoked_flag |= INVOKED_SCALAR;
+      }
     } else {
-      if (computes[i]->invoked_vector != ntimestep)
+      if (!(computes[i]->invoked_flag & INVOKED_VECTOR)) {
 	computes[i]->compute_vector();
+	computes[i]->invoked_flag |= INVOKED_VECTOR;
+      }
     }
-    computes[i]->invoked_flag = 1;
-  }
 
   // if lineflag = MULTILINE, prepend step/cpu header line
 
@@ -826,13 +829,12 @@ void Thermo::create_compute(char *id, char *cstyle, char *extra)
 int Thermo::evaluate_keyword(char *word, double *answer)
 {
   // invoke a lo-level thermo routine to compute the variable value
-  // if keyword requires a compute, is error if thermo doesn't use the compute
-  // if in middle of run and needed compute is not current, invoke it
+  // if keyword requires a compute, error if thermo doesn't use the compute
   // if inbetween runs and needed compute is not current, error
-  // set invoked flag for pe and pressure for keywords that use them
-  //   this insures tallying on future needed steps via clearstep/addstep
+  // if in middle of run and needed compute is not current, invoke it
   // for keywords that use pe indirectly (evdwl, ebond, etc):
   //   check if energy was tallied on this timestep and set pe->invoked_flag 
+  //   this will trigger next timestep for energy tallying via addstep()
 
   if (strcmp(word,"step") == 0) {
     compute_step();
@@ -848,168 +850,196 @@ int Thermo::evaluate_keyword(char *word, double *answer)
 
   } else if (strcmp(word,"temp") == 0) {
     if (!temperature)
-      error->all("Thermo keyword in variable requires thermo to use/init temp");
-    if (temperature->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else temperature->compute_scalar();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init temp");	  
+    if (update->whichflag < 0) {
+      if (temperature->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(temperature->invoked_flag & INVOKED_SCALAR)) {
+      temperature->compute_scalar();
+      temperature->invoked_flag |= INVOKED_SCALAR;
     }
     compute_temp();
     
   } else if (strcmp(word,"press") == 0) {
     if (!pressure)
-      error->all("Thermo keyword in variable requires thermo to use/init press");
-    if (pressure->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pressure->compute_scalar();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init press");
+    if (update->whichflag < 0) {
+      if (pressure->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pressure->invoked_flag & INVOKED_SCALAR)) {
+      pressure->compute_scalar();
+      pressure->invoked_flag |= INVOKED_SCALAR;
     }
-    pressure->invoked_flag = 1;
     compute_press();
 
   } else if (strcmp(word,"pe") == 0) {
     if (!pe)
       error->all("Thermo keyword in variable requires thermo to use/init pe");
-    if (pe->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pe->compute_scalar();
+    if (update->whichflag < 0) {
+      if (pe->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pe->invoked_flag & INVOKED_SCALAR)) {
+      pe->compute_scalar();
+      pe->invoked_flag |= INVOKED_SCALAR;
     }
-    pe->invoked_flag = 1;
     compute_pe();
 
   } else if (strcmp(word,"ke") == 0) {
     if (!temperature)
-      error->all("Thermo keyword in variable requires thermo to use/init temp");
-    if (temperature->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else temperature->compute_scalar();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init temp");
+    if (update->whichflag < 0) {
+      if (temperature->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(temperature->invoked_flag & INVOKED_SCALAR)) {
+      temperature->compute_scalar();
+      temperature->invoked_flag |= INVOKED_SCALAR;
     }
     compute_ke();
 
   } else if (strcmp(word,"etotal") == 0) {
     if (!pe)
       error->all("Thermo keyword in variable requires thermo to use/init pe");
-    if (pe->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pe->compute_scalar();
+    if (update->whichflag < 0) {
+      if (pe->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pe->invoked_flag & INVOKED_SCALAR)) {
+      pe->compute_scalar();
+      pe->invoked_flag |= INVOKED_SCALAR;
     }
     if (!temperature)
-      error->all("Thermo keyword in variable requires thermo to use/init temp");
-    if (temperature->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else temperature->compute_scalar();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init temp");
+    if (update->whichflag < 0) {
+      if (temperature->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(temperature->invoked_flag & INVOKED_SCALAR)) {
+      temperature->compute_scalar();
+      temperature->invoked_flag |= INVOKED_SCALAR;
     }
-    pe->invoked_flag = 1;
     compute_etotal();
 
   } else if (strcmp(word,"enthalpy") == 0) {
     if (!pe)
       error->all("Thermo keyword in variable requires thermo to use/init pe");
-    if (pe->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pe->compute_scalar();
+    if (update->whichflag < 0) {
+      if (pe->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pe->invoked_flag & INVOKED_SCALAR)) {
+      pe->compute_scalar();
+      pe->invoked_flag |= INVOKED_SCALAR;
     }
     if (!temperature)
-      error->all("Thermo keyword in variable requires thermo to use/init temp");
-    if (temperature->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else temperature->compute_scalar();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init temp");
+    if (update->whichflag < 0) {
+      if (temperature->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(temperature->invoked_flag & INVOKED_SCALAR)) {
+      temperature->compute_scalar();
+      temperature->invoked_flag |= INVOKED_SCALAR;
     }
     if (!pressure)
-      error->all("Thermo keyword in variable requires thermo to use/init press");
-    if (pressure->invoked_scalar != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pressure->compute_scalar();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init press");
+    if (update->whichflag < 0) {
+      if (pressure->invoked_scalar != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pressure->invoked_flag & INVOKED_SCALAR)) {
+      pressure->compute_scalar();
+      pressure->invoked_flag |= INVOKED_SCALAR;
     }
-    pe->invoked_flag = 1;
-    pressure->invoked_flag = 1;
     compute_enthalpy();
 
   } else if (strcmp(word,"evdwl") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_evdwl();
 
   } else if (strcmp(word,"ecoul") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_ecoul();
 
   } else if (strcmp(word,"epair") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_epair();
 
   } else if (strcmp(word,"ebond") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_ebond();
 
   } else if (strcmp(word,"eangle") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_eangle();
 
   } else if (strcmp(word,"edihed") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_edihed();
 
   } else if (strcmp(word,"eimp") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_eimp();
 
   } else if (strcmp(word,"emol") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_emol();
 
   } else if (strcmp(word,"elong") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_elong();
 
   } else if (strcmp(word,"etail") == 0) {
-    if (!pe)
-      error->all("Thermo keyword in variable requires thermo to use/init pe");
     if (update->eflag_global != update->ntimestep)
       error->all("Energy was not tallied on needed timestep");
-    pe->invoked_flag = 1;
+    if (!pe)
+      error->all("Thermo keyword in variable requires thermo to use/init pe");
+    pe->invoked_flag |= INVOKED_SCALAR;
     compute_etail();
 
   } else if (strcmp(word,"vol") == 0) compute_vol();
@@ -1030,68 +1060,86 @@ int Thermo::evaluate_keyword(char *word, double *answer)
 
   else if (strcmp(word,"pxx") == 0) {
     if (!pressure)
-      error->all("Thermo keyword in variable requires thermo to use/init press");
-    if (pressure->invoked_vector != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pressure->compute_vector();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init press");
+    if (update->whichflag < 0) {
+      if (pressure->invoked_vector != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pressure->invoked_flag & INVOKED_VECTOR)) {
+      pressure->compute_vector();
+      pressure->invoked_flag |= INVOKED_VECTOR;
     }
-    pressure->invoked_flag = 1;
     compute_pxx();
 
   } else if (strcmp(word,"pyy") == 0) {
     if (!pressure)
-      error->all("Thermo keyword in variable requires thermo to use/init press");
-    if (pressure->invoked_vector != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pressure->compute_vector();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init press");
+    if (update->whichflag < 0) {
+      if (pressure->invoked_vector != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pressure->invoked_flag & INVOKED_VECTOR)) {
+      pressure->compute_vector();
+      pressure->invoked_flag |= INVOKED_VECTOR;
     }
-    pressure->invoked_flag = 1;
     compute_pyy();
 
   } else if (strcmp(word,"pzz") == 0) {
     if (!pressure)
-      error->all("Thermo keyword in variable requires thermo to use/init press");
-    if (pressure->invoked_vector != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pressure->compute_vector();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init press");
+    if (update->whichflag < 0) {
+      if (pressure->invoked_vector != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pressure->invoked_flag & INVOKED_VECTOR)) {
+      pressure->compute_vector();
+      pressure->invoked_flag |= INVOKED_VECTOR;
     }
-    pressure->invoked_flag = 1;
     compute_pzz();
 
   } else if (strcmp(word,"pxy") == 0) {
     if (!pressure)
-      error->all("Thermo keyword in variable requires thermo to use/init press");
-    if (pressure->invoked_vector != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pressure->compute_vector();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init press");
+    if (update->whichflag < 0) {
+      if (pressure->invoked_vector != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pressure->invoked_flag & INVOKED_VECTOR)) {
+      pressure->compute_vector();
+      pressure->invoked_flag |= INVOKED_VECTOR;
     }
-    pressure->invoked_flag = 1;
     compute_pxy();
 
   } else if (strcmp(word,"pxz") == 0) {
     if (!pressure)
-      error->all("Thermo keyword in variable requires thermo to use/init press");
-    if (pressure->invoked_vector != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pressure->compute_vector();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init press");
+    if (update->whichflag < 0) {
+      if (pressure->invoked_vector != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pressure->invoked_flag & INVOKED_VECTOR)) {
+      pressure->compute_vector();
+      pressure->invoked_flag |= INVOKED_VECTOR;
     }
-    pressure->invoked_flag = 1;
     compute_pxz();
 
   } else if (strcmp(word,"pyz") == 0) {
     if (!pressure)
-      error->all("Thermo keyword in variable requires thermo to use/init press");
-    if (pressure->invoked_vector != update->ntimestep) {
-      if (update->whichflag < 0)
-	error->all("Compute used in variable thermo keyword is not current");
-      else pressure->compute_vector();
+      error->all("Thermo keyword in variable requires "
+		 "thermo to use/init press");
+    if (update->whichflag < 0) {
+      if (pressure->invoked_vector != update->ntimestep)
+	error->all("Compute used in variable thermo keyword between runs "
+		   "is not current");
+    } else if (!(pressure->invoked_flag & INVOKED_VECTOR)) {
+      pressure->compute_vector();
+      pressure->invoked_flag |= INVOKED_VECTOR;
     }
-    pressure->invoked_flag = 1;
     compute_pyz();
 
   } else return 1;
@@ -1146,8 +1194,7 @@ void Thermo::compute_fix()
 
 void Thermo::compute_variable()
 {
-  int index = field2index[ifield];
-  dvalue = input->variable->compute_equal(variables[index]);
+  dvalue = input->variable->compute_equal(variables[field2index[ifield]]);
 }
 
 /* ----------------------------------------------------------------------
diff --git a/src/variable.cpp b/src/variable.cpp
index d0d1f7fb91..39f2e32fa7 100644
--- a/src/variable.cpp
+++ b/src/variable.cpp
@@ -37,6 +37,7 @@ using namespace LAMMPS_NS;
 
 #define MYROUND(a) (( a-floor(a) ) >= .5) ? ceil(a) : floor(a)
 
+enum{DUMMY0,INVOKED_SCALAR,INVOKED_VECTOR,DUMMMY3,INVOKED_PERATOM};
 enum{INDEX,LOOP,EQUAL,WORLD,UNIVERSE,ULOOP,ATOM};
 enum{ARG,OP};
 enum{DONE,ADD,SUBTRACT,MULTIPLY,DIVIDE,CARAT,UNARY,
@@ -642,7 +643,6 @@ double Variable::evaluate(char *str, Tree **tree)
 	int icompute = modify->find_compute(id);
 	if (icompute < 0) error->all("Invalid compute ID in variable formula");
 	Compute *compute = modify->compute[icompute];
-	compute->invoked_flag = 1;
 	delete [] id;
 
 	if (domain->box_exist == 0)
@@ -670,11 +670,15 @@ double Variable::evaluate(char *str, Tree **tree)
 
 	if (nbracket == 0 && compute->scalar_flag) {
 
-	  if (compute->invoked_scalar != update->ntimestep) {
-	    if (update->whichflag < 0)
-	      error->all("Compute used in variable is not current");
-	    else compute->compute_scalar();
+	  if (update->whichflag < 0) {
+	    if (compute->invoked_scalar != update->ntimestep)
+	      error->all("Compute used in variable between runs "
+			 "is not current");
+	  } else if (!(compute->invoked_flag & INVOKED_SCALAR)) {
+	    compute->compute_scalar();
+	    compute->invoked_flag |= INVOKED_SCALAR;
 	  }
+
 	  value1 = compute->scalar;
 	  if (tree) {
 	    Tree *newtree = new Tree();
@@ -690,11 +694,15 @@ double Variable::evaluate(char *str, Tree **tree)
 
 	  if (index1 > compute->size_vector)
 	      error->all("Compute vector in variable formula is too small");
-	  if (compute->invoked_vector != update->ntimestep) {
-	    if (update->whichflag < 0)
-	      error->all("Compute used in variable is not current");
-	    else compute->compute_vector();
+	  if (update->whichflag < 0) {
+	    if (compute->invoked_vector != update->ntimestep)
+	      error->all("Compute used in variable between runs "
+			 "is not current");
+	  } else if (!(compute->invoked_flag & INVOKED_VECTOR)) {
+	    compute->compute_vector();
+	    compute->invoked_flag |= INVOKED_VECTOR;
 	  }
+
 	  value1 = compute->vector[index1-1];
 	  if (tree) {
 	    Tree *newtree = new Tree();
@@ -711,11 +719,15 @@ double Variable::evaluate(char *str, Tree **tree)
 
 	  if (tree == NULL)
 	    error->all("Per-atom compute in equal-style variable formula");
-	  if (compute->invoked_peratom != update->ntimestep) {
-	    if (update->whichflag < 0)
-	      error->all("Compute used in variable is not current");
-	    else compute->compute_peratom();
+	  if (update->whichflag < 0) {
+	    if (compute->invoked_peratom != update->ntimestep)
+	      error->all("Compute used in variable between runs "
+			 "is not current");
+	  } else if (!(compute->invoked_flag & INVOKED_PERATOM)) {
+	    compute->compute_peratom();
+	    compute->invoked_flag |= INVOKED_PERATOM;
 	  }
+
 	  Tree *newtree = new Tree();
 	  newtree->type = ATOMARRAY;
 	  newtree->array = compute->scalar_atom;
@@ -728,11 +740,15 @@ double Variable::evaluate(char *str, Tree **tree)
 	} else if (nbracket == 1 && index1 > 0 && 
 		   compute->peratom_flag && compute->size_peratom == 0) {
 
-	  if (compute->invoked_peratom != update->ntimestep) {
-	    if (update->whichflag < 0)
-	      error->all("Compute used in variable is not current");
-	    else compute->compute_peratom();
+	  if (update->whichflag < 0) {
+	    if (compute->invoked_peratom != update->ntimestep)
+	      error->all("Compute used in variable between runs "
+			 "is not current");
+	  } else if (!(compute->invoked_flag & INVOKED_PERATOM)) {
+	    compute->compute_peratom();
+	    compute->invoked_flag |= INVOKED_PERATOM;
 	  }
+
 	  peratom2global(1,NULL,compute->scalar_atom,1,index1,
 			 tree,treestack,ntreestack,argstack,nargstack);
 
@@ -745,11 +761,15 @@ double Variable::evaluate(char *str, Tree **tree)
 	    error->all("Per-atom compute in equal-style variable formula");
 	  if (index2 > compute->size_peratom)
 	    error->all("Compute vector in variable formula is too small");
-	  if (compute->invoked_peratom != update->ntimestep) {
-	    if (update->whichflag < 0)
-	      error->all("Compute used in variable is not current");
-	    else compute->compute_peratom();
+	  if (update->whichflag < 0) {
+	    if (compute->invoked_peratom != update->ntimestep)
+	      error->all("Compute used in variable between runs "
+			 "is not current");
+	  } else if (!(compute->invoked_flag & INVOKED_PERATOM)) {
+	    compute->compute_peratom();
+	    compute->invoked_flag |= INVOKED_PERATOM;
 	  }
+
 	  Tree *newtree = new Tree();
 	  newtree->type = ATOMARRAY;
 	  newtree->array = &compute->vector_atom[0][index2-1];
@@ -764,11 +784,15 @@ double Variable::evaluate(char *str, Tree **tree)
 
 	  if (index2 > compute->size_peratom)
 	    error->all("Compute vector in variable formula is too small");
-	  if (compute->invoked_peratom != update->ntimestep) {
-	    if (update->whichflag < 0)
-	      error->all("Compute used in variable is not current");
-	    else compute->compute_peratom();
+	  if (update->whichflag < 0) {
+	    if (compute->invoked_peratom != update->ntimestep)
+	      error->all("Compute used in variable between runs "
+			 "is not current");
+	  } else if (!(compute->invoked_flag & INVOKED_PERATOM)) {
+	    compute->compute_peratom();
+	    compute->invoked_flag |= INVOKED_PERATOM;
 	  }
+
 	  peratom2global(1,NULL,&compute->vector_atom[0][index2-1],
 			 compute->size_peratom,index1,
 			 tree,treestack,ntreestack,argstack,nargstack);