git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@1591 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/ASPHERE/fix_npt_asphere.cpp

@@ -79,7 +79,7 @@ void FixNPTASphere::initial_integrate(int vflag)
   }
   ang_factor = exp(-dthalf*eta_dot);
 
-  // v update only for atoms in NPT group
+  // v update only for atoms in group
 
   double **x = atom->x;
   double **v = atom->v;
@@ -107,7 +107,7 @@ void FixNPTASphere::initial_integrate(int vflag)
 
   remap(0);
 
-  // x update by full step only for atoms in NPT group
+  // x update by full step only for atoms in group
 
   for (i = 0; i < nlocal; i++) {
     if (mask[i] & groupbit) {
@@ -147,7 +147,7 @@ void FixNPTASphere::final_integrate()
 {
   int i;
 
-  // v update only for atoms in NPT group
+  // v update only for atoms in group
 
   double **v = atom->v;
   double **f = atom->f;

src/ASPHERE/fix_nvt_asphere.cpp

@@ -61,7 +61,7 @@ void FixNVTASphere::initial_integrate(int vflag)
   eta += dtv*eta_dot;
   factor = exp(-dthalf*eta_dot);
 
-  // update v and x of only atoms in NVT group
+  // update v and x of only atoms in group
 
   double **x = atom->x;
   double **v = atom->v;
@@ -106,7 +106,7 @@ void FixNVTASphere::final_integrate()
 {
   double dtfm;
 
-  // update v of only atoms in NVT group
+  // update v of only atoms in group
 
   double **v = atom->v;
   double **f = atom->f;

src/compute.cpp

@@ -60,6 +60,7 @@ Compute::Compute(LAMMPS *lmp, int narg, char **arg) : Pointers(lmp)
   scalar_flag = vector_flag = peratom_flag = 0;
   tempflag = pressflag = peflag = 0;
   pressatomflag = peatomflag = 0;
+  tempbias = 0;
   id_pre = NULL;
   timeflag = 0;
   invoked = 0;
@@ -162,3 +163,16 @@ int Compute::matchstep(int ntimestep)
   }
   return 0;
 }
+
+/* ----------------------------------------------------------------------
+   add back in velocity bias removed by remove_bias() to leave thermal temp
+   assume remove_bias() was previously called for this atom
+------------------------------------------------------------------------- */
+
+void Compute::restore_bias(double *v)
+{
+  v[0] += vbias[0];
+  v[1] += vbias[1];
+  v[2] += vbias[2];
+}
+

src/compute.h

@@ -45,6 +45,9 @@ class Compute : protected Pointers {
   int peflag;         // 1 if Compute calculates PE (uses Force energies)
   int peatomflag;     // 1 if Compute calculates per-atom PE
 
+  int tempbias;       // 0/1 if has bias routines for isolating thermal temp
+  double vbias[3];    // stored velocity bias for one atom
+
   char *id_pre;       // ID of pre-compute the Compute may store
 
   int timeflag;       // 1 if Compute stores list of timesteps it's called on
@@ -73,6 +76,9 @@ class Compute : protected Pointers {
   virtual int pack_reverse_comm(int, int, double *) {return 0;}
   virtual void unpack_reverse_comm(int, int *, double *) {}
 
+  virtual void remove_bias(int, double *) {}
+  void restore_bias(double *);
+
   void addstep(int);
   int matchstep(int);
 

src/compute_temp_com.cpp

@@ -44,6 +44,8 @@ ComputeTempCOM::ComputeTempCOM(LAMMPS *lmp, int narg, char **arg) :
   extscalar = 0;
   extvector = 1;
   tempflag = 1;
+  tempbias = 1;
+  vbias[0] = vbias[1] = vbias[2] = 0.0;
 
   vector = new double[6];
 }
@@ -81,12 +83,12 @@ void ComputeTempCOM::recount()
 
 double ComputeTempCOM::compute_scalar()
 {
-  double vcm[3],vthermal[3];
+  double vthermal[3];
 
   invoked |= INVOKED_SCALAR;
 
   if (dynamic) masstotal = group->mass(igroup);
-  group->vcm(igroup,masstotal,vcm);
+  group->vcm(igroup,masstotal,vbias);
 
   double **v = atom->v;
   double *mass = atom->mass;
@@ -98,9 +100,9 @@ double ComputeTempCOM::compute_scalar()
   double t = 0.0;
   for (int i = 0; i < nlocal; i++)
     if (mask[i] & groupbit) {
-      vthermal[0] = v[i][0] - vcm[0];
+      vthermal[0] = v[i][0] - vbias[0];
-      vthermal[1] = v[i][1] - vcm[1];
+      vthermal[1] = v[i][1] - vbias[1];
-      vthermal[2] = v[i][2] - vcm[2];
+      vthermal[2] = v[i][2] - vbias[2];
       if (mass)
 	t += (vthermal[0]*vthermal[0] + vthermal[1]*vthermal[1] + 
 	      vthermal[2]*vthermal[2]) * mass[type[i]];
@@ -120,12 +122,12 @@ double ComputeTempCOM::compute_scalar()
 void ComputeTempCOM::compute_vector()
 {
   int i;
-  double vcm[3],vthermal[3];
+  double vthermal[3];
 
   invoked |= INVOKED_VECTOR;
 
   if (dynamic) masstotal = group->mass(igroup);
-  group->vcm(igroup,masstotal,vcm);
+  group->vcm(igroup,masstotal,vbias);
 
   double **x = atom->x;
   double **v = atom->v;
@@ -140,9 +142,9 @@ void ComputeTempCOM::compute_vector()
 
   for (i = 0; i < nlocal; i++)
     if (mask[i] & groupbit) {
-      vthermal[0] = v[i][0] - vcm[0];
+      vthermal[0] = v[i][0] - vbias[0];
-      vthermal[1] = v[i][1] - vcm[1];
+      vthermal[1] = v[i][1] - vbias[1];
-      vthermal[2] = v[i][2] - vcm[2];
+      vthermal[2] = v[i][2] - vbias[2];
 
       if (mass) massone = mass[type[i]];
       else massone = rmass[i];
@@ -157,3 +159,12 @@ void ComputeTempCOM::compute_vector()
   MPI_Allreduce(t,vector,6,MPI_DOUBLE,MPI_SUM,world);
   for (i = 0; i < 6; i++) vector[i] *= force->mvv2e;
 }
+
+/* ---------------------------------------------------------------------- */
+
+void ComputeTempCOM::remove_bias(int i, double *v)
+{
+  v[0] = v[0] - vbias[0];
+  v[1] = v[1] - vbias[1];
+  v[2] = v[2] - vbias[2];
+}

src/compute_temp_com.h

@@ -25,6 +25,7 @@ class ComputeTempCOM : public Compute {
   void init();
   double compute_scalar();
   void compute_vector();
+  void remove_bias(int, double *);
 
  private:
   int fix_dof;

src/compute_temp_deform.cpp

@@ -46,6 +46,7 @@ ComputeTempDeform::ComputeTempDeform(LAMMPS *lmp, int narg, char **arg) :
   extscalar = 0;
   extvector = 1;
   tempflag = 1;
+  tempbias = 1;
 
   vector = new double[6];
 }
@@ -198,3 +199,21 @@ void ComputeTempDeform::compute_vector()
   MPI_Allreduce(t,vector,6,MPI_DOUBLE,MPI_SUM,world);
   for (int i = 0; i < 6; i++) vector[i] *= force->mvv2e;
 }
+
+/* ---------------------------------------------------------------------- */
+
+void ComputeTempDeform::remove_bias(int i, double *v)
+{
+  double lamda[3];
+  double *h_rate = domain->h_rate;
+  double *h_ratelo = domain->h_ratelo;
+
+  domain->x2lamda(atom->x[i],lamda);
+  vbias[0] = h_rate[0]*lamda[0] + h_rate[5]*lamda[1] + 
+    h_rate[4]*lamda[2] + h_ratelo[0];
+  vbias[1] = h_rate[1]*lamda[1] + h_rate[3]*lamda[2] + h_ratelo[1];
+  vbias[2] = h_rate[2]*lamda[2] + h_ratelo[2];
+  v[0] -= vbias[0];
+  v[1] -= vbias[1];
+  v[2] -= vbias[2];
+}

src/compute_temp_deform.h

@@ -25,6 +25,7 @@ class ComputeTempDeform : public Compute {
   void init();
   double compute_scalar();
   void compute_vector();
+  void remove_bias(int, double *);
 
  private:
   int fix_dof;

src/compute_temp_partial.cpp

@@ -42,6 +42,8 @@ ComputeTempPartial::ComputeTempPartial(LAMMPS *lmp, int narg, char **arg) :
   extscalar = 0;
   extvector = 1;
   tempflag = 1;
+  tempbias = 1;
+  vbias[0] = vbias[1] = vbias[2] = 0.0;
 
   vector = new double[6];
 }
@@ -140,3 +142,21 @@ void ComputeTempPartial::compute_vector()
   MPI_Allreduce(t,vector,6,MPI_DOUBLE,MPI_SUM,world);
   for (i = 0; i < 6; i++) vector[i] *= force->mvv2e;
 }
+
+/* ---------------------------------------------------------------------- */
+
+void ComputeTempPartial::remove_bias(int i, double *v)
+{
+  if (!xflag) {
+    vbias[0] = v[0];
+    v[0] = 0.0;
+  }
+  if (!yflag) {
+    vbias[1] = v[1];
+    v[1] = 0.0;
+  }
+  if (!zflag) {
+    vbias[2] = v[2];
+    v[2] = 0.0;
+  }
+}

src/compute_temp_partial.h

@@ -25,6 +25,7 @@ class ComputeTempPartial : public Compute {
   void init();
   double compute_scalar();
   void compute_vector();
+  void remove_bias(int, double *);
 
  private:
   int xflag,yflag,zflag;

src/compute_temp_ramp.cpp

@@ -107,6 +107,8 @@ ComputeTempRamp::ComputeTempRamp(LAMMPS *lmp, int narg, char **arg) :
   extscalar = 0;
   extvector = 1;
   tempflag = 1;
+  tempbias = 1;
+  vbias[0] = vbias[1] = vbias[2] = 0.0;
 
   vector = new double[6];
 }
@@ -224,3 +226,14 @@ void ComputeTempRamp::compute_vector()
   MPI_Allreduce(t,vector,6,MPI_DOUBLE,MPI_SUM,world);
   for (i = 0; i < 6; i++) vector[i] *= force->mvv2e;
 }
+
+/* ---------------------------------------------------------------------- */
+
+void ComputeTempRamp::remove_bias(int i, double *v)
+{
+  double fraction = (atom->x[i][coord_dim] - coord_lo) / (coord_hi - coord_lo);
+  fraction = MAX(fraction,0.0);
+  fraction = MIN(fraction,1.0);
+  vbias[v_dim] = v_lo + fraction*(v_hi - v_lo);
+  v[v_dim] -= vbias[v_dim];
+}

src/compute_temp_ramp.h

@@ -25,6 +25,7 @@ class ComputeTempRamp : public Compute {
   void init();
   double compute_scalar();
   void compute_vector();
+  void remove_bias(int, double *);
 
  private:
   int coord_dim;

src/compute_temp_region.cpp

@@ -40,6 +40,7 @@ ComputeTempRegion::ComputeTempRegion(LAMMPS *lmp, int narg, char **arg) :
   extscalar = 0;
   extvector = 1;
   tempflag = 1;
+  tempbias = 1;
 
   vector = new double[6];
 }
@@ -137,3 +138,19 @@ void ComputeTempRegion::compute_vector()
   MPI_Allreduce(t,vector,6,MPI_DOUBLE,MPI_SUM,world);
   for (i = 0; i < 6; i++) vector[i] *= force->mvv2e;
 }
+
+/* ---------------------------------------------------------------------- */
+
+void ComputeTempRegion::remove_bias(int i, double *v)
+{
+  double *x = atom->x[i];
+  if (atom->mask[i] & groupbit && 
+      domain->regions[iregion]->match(x[0],x[1],x[2]))
+    vbias[0] = vbias[1] = vbias[2] = 0.0;
+  else {
+    vbias[0] = v[0];
+    vbias[1] = v[1];
+    vbias[2] = v[2];
+    v[0] = v[1] = v[2] = 0.0;
+  }
+}

src/compute_temp_region.h

@@ -25,6 +25,7 @@ class ComputeTempRegion : public Compute {
   void init();
   double compute_scalar();
   void compute_vector();
+  void remove_bias(int, double *);
 
  private:
   int iregion;

src/fix.h

@@ -106,6 +106,7 @@ class Fix : protected Pointers {
 
   virtual int dof(int) {return 0;}
   virtual void deform(int) {}
+  virtual void reset_target(double) {}
   virtual void reset_dt() {}
 
   virtual int modify_param(int, char **) {return 0;}

src/fix_langevin.cpp

@@ -19,6 +19,8 @@
 #include "atom.h"
 #include "force.h"
 #include "update.h"
+#include "modify.h"
+#include "compute.h"
 #include "domain.h"
 #include "region.h"
 #include "respa.h"
@@ -28,6 +30,8 @@
 
 using namespace LAMMPS_NS;
 
+enum{NOBIAS,BIAS};
+
 /* ---------------------------------------------------------------------- */
 
 FixLangevin::FixLangevin(LAMMPS *lmp, int narg, char **arg) :
@@ -55,19 +59,11 @@ FixLangevin::FixLangevin(LAMMPS *lmp, int narg, char **arg) :
   
   // optional args
 
-  flagx = flagy = flagz = 1;
   for (int i = 1; i <= atom->ntypes; i++) ratio[i] = 1.0;
-  iregion = -1;
 
   int iarg = 7;
   while (iarg < narg) {
-    if (strcmp(arg[iarg],"axes") == 0) {
+    if (strcmp(arg[iarg],"scale") == 0) {
-      if (iarg+4 > narg) error->all("Illegal fix langevin command");
-      flagx = atoi(arg[iarg+1]);
-      flagy = atoi(arg[iarg+2]);
-      flagz = atoi(arg[iarg+3]);
-      iarg += 4;
-    } else if (strcmp(arg[iarg],"scale") == 0) {
       if (iarg+3 > narg) error->all("Illegal fix langevin command");
       int itype = atoi(arg[iarg+1]);
       double scale = atof(arg[iarg+2]);
@@ -75,13 +71,13 @@ FixLangevin::FixLangevin(LAMMPS *lmp, int narg, char **arg) :
 	error->all("Illegal fix langevin command");
       ratio[itype] = scale;
       iarg += 3;
-    } else if (strcmp(arg[iarg],"region") == 0) {
-      if (iarg+2 > narg) error->all("Illegal fix langevin command");
-      iregion = domain->find_region(arg[iarg+1]);
-      if (iregion == -1) error->all("Fix langevin region ID does not exist");
-      iarg += 2;
     } else error->all("Illegal fix langevin command");
   }
+
+  // set temperature = NULL, user can override via fix_modify if wants bias
+
+  id_temp = NULL;
+  temperature = NULL;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -92,6 +88,7 @@ FixLangevin::~FixLangevin()
   delete [] gfactor1;
   delete [] gfactor2;
   delete [] ratio;
+  delete [] id_temp;
 }
 
 /* ---------------------------------------------------------------------- */
@@ -121,6 +118,9 @@ void FixLangevin::init()
     gfactor2[i] *= 1.0/sqrt(ratio[i]);
   }
 
+  if (temperature && temperature->tempbias) which = BIAS;
+  else which = NOBIAS;
+
   if (strcmp(update->integrate_style,"respa") == 0)
     nlevels_respa = ((Respa *) update->integrate)->nlevels;
 }
@@ -142,6 +142,8 @@ void FixLangevin::setup(int vflag)
 
 void FixLangevin::post_force(int vflag)
 {
+  double gamma1,gamma2;
+
   double **x = atom->x;
   double **v = atom->v;
   double **f = atom->f;
@@ -154,34 +156,40 @@ void FixLangevin::post_force(int vflag)
   double t_target = t_start + delta * (t_stop-t_start);
   double tsqrt = sqrt(t_target);
 
-  double gamma1,gamma2;
+  // apply damping and thermostat to appropriate atoms
 
-  // apply damping and thermostat to all atoms in fix group
+  if (which == NOBIAS) {
-
-  if (iregion == -1) {
     for (int i = 0; i < nlocal; i++) {
       if (mask[i] & groupbit) {
 	gamma1 = gfactor1[type[i]];
 	gamma2 = gfactor2[type[i]] * tsqrt;
-	if (flagx) f[i][0] += gamma1*v[i][0] + gamma2*(random->uniform()-0.5);
+	f[i][0] += gamma1*v[i][0] + gamma2*(random->uniform()-0.5);
-	if (flagy) f[i][1] += gamma1*v[i][1] + gamma2*(random->uniform()-0.5);
+	f[i][1] += gamma1*v[i][1] + gamma2*(random->uniform()-0.5);
-	if (flagz) f[i][2] += gamma1*v[i][2] + gamma2*(random->uniform()-0.5);
+	f[i][2] += gamma1*v[i][2] + gamma2*(random->uniform()-0.5);
       }
     }
 
-  // apply damping and thermostat to all atoms in fix group and in region
+  // invoke temperature since some computes require it to remove bias
+  // test on v = 0 since some computes mask non-participating atoms via v = 0
+
+  } else if (which == BIAS) {
+    double tmp = temperature->compute_scalar();
 
-  } else {
     for (int i = 0; i < nlocal; i++) {
-      if (mask[i] & groupbit &&
+      if (mask[i] & groupbit) {
-	  domain->regions[iregion]->match(x[i][0],x[i][1],x[i][2])) {
 	gamma1 = gfactor1[type[i]];
 	gamma2 = gfactor2[type[i]] * tsqrt;
-	if (flagx) f[i][0] += gamma1*v[i][0] + gamma2*(random->uniform()-0.5);
+	temperature->remove_bias(i,v[i]);
-	if (flagy) f[i][1] += gamma1*v[i][1] + gamma2*(random->uniform()-0.5);
+	if (v[i][0] != 0.0)
-	if (flagz) f[i][2] += gamma1*v[i][2] + gamma2*(random->uniform()-0.5);
+	  f[i][0] += gamma1*v[i][0] + gamma2*(random->uniform()-0.5);
+	if (v[i][1] != 0.0)
+	  f[i][1] += gamma1*v[i][1] + gamma2*(random->uniform()-0.5);
+	if (v[i][2] != 0.0)
+	  f[i][2] += gamma1*v[i][2] + gamma2*(random->uniform()-0.5);
+	temperature->restore_bias(v[i]);
       }
     }
+
   }
 }
 
@@ -209,3 +217,27 @@ void FixLangevin::reset_dt()
     gfactor2[i] *= 1.0/sqrt(ratio[i]);
   }
 }
+
+/* ---------------------------------------------------------------------- */
+
+int FixLangevin::modify_param(int narg, char **arg)
+{
+  if (strcmp(arg[0],"temp") == 0) {
+    if (narg < 2) error->all("Illegal fix_modify command");
+    delete [] id_temp;
+    int n = strlen(arg[1]) + 1;
+    id_temp = new char[n];
+    strcpy(id_temp,arg[1]);
+
+    int icompute = modify->find_compute(id_temp);
+    if (icompute < 0) error->all("Could not find fix_modify temp ID");
+    temperature = modify->compute[icompute];
+
+    if (temperature->tempflag == 0)
+      error->all("Fix_modify temp ID does not compute temperature");
+    if (temperature->igroup != igroup && comm->me == 0)
+      error->warning("Group for fix_modify temp != fix group");
+    return 2;
+  }
+  return 0;
+}

src/fix_langevin.h

@@ -29,12 +29,16 @@ class FixLangevin : public Fix {
   void post_force_respa(int, int, int);
   void reset_target(double);
   void reset_dt();
+  int modify_param(int, char **);
 
  private:
+  int which;
   double t_start,t_stop,t_period;
-  int flagx,flagy,flagz,iregion;
   double *gfactor1,*gfactor2,*ratio;
 
+  char *id_temp;
+  class Compute *temperature;
+
   int nlevels_respa;
   class RanMars *random;
 };

src/fix_npt.cpp

@@ -36,6 +36,8 @@ using namespace LAMMPS_NS;
 #define MIN(A,B) ((A) < (B)) ? (A) : (B)
 #define MAX(A,B) ((A) > (B)) ? (A) : (B)
 
+enum{NOBIAS,BIAS};
+
 /* ---------------------------------------------------------------------- */
 
 FixNPT::FixNPT(LAMMPS *lmp, int narg, char **arg) :
@@ -257,6 +259,9 @@ void FixNPT::init()
   if (icompute < 0) error->all("Temp ID for fix npt does not exist");
   temperature = modify->compute[icompute];
 
+  if (temperature->tempbias) which = BIAS;
+  else which = NOBIAS;
+
   icompute = modify->find_compute(id_press);
   if (icompute < 0) error->all("Press ID for fix npt does not exist");
   pressure = modify->compute[icompute];
@@ -365,7 +370,7 @@ void FixNPT::initial_integrate(int vflag)
     dilation[i] = exp(dthalf*omega_dot[i]);
   }
 
-  // v update only for atoms in NPT group
+  // v update only for atoms in group
 
   double **x = atom->x;
   double **v = atom->v;
@@ -377,12 +382,27 @@ void FixNPT::initial_integrate(int vflag)
   if (igroup == atom->firstgroup) nlocal = atom->nfirst;
 
   double dtfm;
-  for (i = 0; i < nlocal; i++) {
+
-    if (mask[i] & groupbit) {
+  if (which == NOBIAS) {
-      dtfm = dtf / mass[type[i]];
+    for (i = 0; i < nlocal; i++) {
-      v[i][0] = v[i][0]*factor[0] + dtfm*f[i][0];
+      if (mask[i] & groupbit) {
-      v[i][1] = v[i][1]*factor[1] + dtfm*f[i][1];
+	dtfm = dtf / mass[type[i]];
-      v[i][2] = v[i][2]*factor[2] + dtfm*f[i][2];
+	v[i][0] = v[i][0]*factor[0] + dtfm*f[i][0];
+	v[i][1] = v[i][1]*factor[1] + dtfm*f[i][1];
+	v[i][2] = v[i][2]*factor[2] + dtfm*f[i][2];
+      }
+    }
+
+  } else if (which == BIAS) {
+    for (i = 0; i < nlocal; i++) {
+      if (mask[i] & groupbit) {
+	temperature->remove_bias(i,v[i]);
+	dtfm = dtf / mass[type[i]];
+	v[i][0] = v[i][0]*factor[0] + dtfm*f[i][0];
+	v[i][1] = v[i][1]*factor[1] + dtfm*f[i][1];
+	v[i][2] = v[i][2]*factor[2] + dtfm*f[i][2];
+	temperature->restore_bias(v[i]);
+      }
     }
   }
 
@@ -390,7 +410,7 @@ void FixNPT::initial_integrate(int vflag)
 
   remap(0);
 
-  // x update by full step only for atoms in NPT group
+  // x update by full step only for atoms in group
 
   for (i = 0; i < nlocal; i++) {
     if (mask[i] & groupbit) {
@@ -415,7 +435,7 @@ void FixNPT::final_integrate()
 {
   int i;
 
-  // v update only for atoms in NPT group
+  // v update only for atoms in group
 
   double **v = atom->v;
   double **f = atom->f;
@@ -426,12 +446,27 @@ void FixNPT::final_integrate()
   if (igroup == atom->firstgroup) nlocal = atom->nfirst;
 
   double dtfm;
-  for (i = 0; i < nlocal; i++) {
+
-    if (mask[i] & groupbit) {
+  if (which == NOBIAS) {
-      dtfm = dtf / mass[type[i]];
+    for (i = 0; i < nlocal; i++) {
-      v[i][0] = (v[i][0] + dtfm*f[i][0]) * factor[0];
+      if (mask[i] & groupbit) {
-      v[i][1] = (v[i][1] + dtfm*f[i][1]) * factor[1];
+	dtfm = dtf / mass[type[i]];
-      v[i][2] = (v[i][2] + dtfm*f[i][2]) * factor[2];
+	v[i][0] = (v[i][0] + dtfm*f[i][0]) * factor[0];
+	v[i][1] = (v[i][1] + dtfm*f[i][1]) * factor[1];
+	v[i][2] = (v[i][2] + dtfm*f[i][2]) * factor[2];
+      }
+    }
+
+  } else if (which == BIAS) {
+    for (i = 0; i < nlocal; i++) {
+      if (mask[i] & groupbit) {
+	temperature->remove_bias(i,v[i]);
+	dtfm = dtf / mass[type[i]];
+	v[i][0] = (v[i][0] + dtfm*f[i][0]) * factor[0];
+	v[i][1] = (v[i][1] + dtfm*f[i][1]) * factor[1];
+	v[i][2] = (v[i][2] + dtfm*f[i][2]) * factor[2];
+	temperature->restore_bias(v[i]);
+      }
     }
   }
 
@@ -505,7 +540,7 @@ void FixNPT::initial_integrate_respa(int vflag, int ilevel, int flag)
 
   // outermost level - update eta_dot and omega_dot, apply to v, remap box
   // all other levels - NVE update of v
-  // x,v updates only performed for atoms in NPT group
+  // x,v updates only performed for atoms in group
 
   if (ilevel == nlevels_respa-1) {
 
@@ -538,7 +573,7 @@ void FixNPT::initial_integrate_respa(int vflag, int ilevel, int flag)
       dilation[i] = exp(dthalf*omega_dot[i]);
     }
 
-    // v update only for atoms in NPT group
+    // v update only for atoms in group
 
     for (int i = 0; i < nlocal; i++) {
       if (mask[i] & groupbit) {
@@ -555,19 +590,33 @@ void FixNPT::initial_integrate_respa(int vflag, int ilevel, int flag)
 
   } else {
 
-    // v update only for atoms in NPT group
+    // v update only for atoms in group
 
-    for (int i = 0; i < nlocal; i++) {
+    if (which == NOBIAS) {
-      if (mask[i] & groupbit) {
+      for (int i = 0; i < nlocal; i++) {
-	dtfm = dtf / mass[type[i]];
+	if (mask[i] & groupbit) {
-	v[i][0] += dtfm*f[i][0];
+	  dtfm = dtf / mass[type[i]];
-	v[i][1] += dtfm*f[i][1];
+	  v[i][0] += dtfm*f[i][0];
-	v[i][2] += dtfm*f[i][2];
+	  v[i][1] += dtfm*f[i][1];
+	  v[i][2] += dtfm*f[i][2];
+	}
+      }
+
+    } else if (which == BIAS) {
+      for (int i = 0; i < nlocal; i++) {
+	if (mask[i] & groupbit) {
+	  temperature->remove_bias(i,v[i]);
+	  dtfm = dtf / mass[type[i]];
+	  v[i][0] += dtfm*f[i][0];
+	  v[i][1] += dtfm*f[i][1];
+	  v[i][2] += dtfm*f[i][2];
+	  temperature->restore_bias(v[i]);
+	}
       }
     }
   }
 
-  // innermost level - also update x only for atoms in NPT group
+  // innermost level - also update x only for atoms in group
 
   if (ilevel == 0) {
     for (int i = 0; i < nlocal; i++) {
@@ -594,12 +643,12 @@ void FixNPT::final_integrate_respa(int ilevel)
   // outermost level - update eta_dot and omega_dot,
   //   apply to v via final_integrate()
   // all other levels - NVE update of v
-  // v update only performed for atoms in NPT group
+  // v update only performed for atoms in group
 
   if (ilevel == nlevels_respa-1) final_integrate();
   else {
 
-    // v update only for atoms in NPT group
+    // v update only for atoms in group
 
     double **v = atom->v;
     double **f = atom->f;
@@ -609,12 +658,26 @@ void FixNPT::final_integrate_respa(int ilevel)
     int nlocal = atom->nlocal;
     if (igroup == atom->firstgroup) nlocal = atom->nfirst;
 
-    for (int i = 0; i < nlocal; i++) {
+    if (which == NOBIAS) {
-      if (mask[i] & groupbit) {
+      for (int i = 0; i < nlocal; i++) {
-	dtfm = dtf / mass[type[i]];
+	if (mask[i] & groupbit) {
-	v[i][0] += dtfm*f[i][0];
+	  dtfm = dtf / mass[type[i]];
-	v[i][1] += dtfm*f[i][1];
+	  v[i][0] += dtfm*f[i][0];
-	v[i][2] += dtfm*f[i][2];
+	  v[i][1] += dtfm*f[i][1];
+	  v[i][2] += dtfm*f[i][2];
+	}
+      }
+
+    } else if (which == BIAS) {
+      for (int i = 0; i < nlocal; i++) {
+	if (mask[i] & groupbit) {
+	  temperature->remove_bias(i,v[i]);
+	  dtfm = dtf / mass[type[i]];
+	  v[i][0] += dtfm*f[i][0];
+	  v[i][1] += dtfm*f[i][1];
+	  v[i][2] += dtfm*f[i][2];
+	  temperature->restore_bias(v[i]);
+	}
       }
     }
   }
@@ -763,7 +826,7 @@ int FixNPT::modify_param(int narg, char **arg)
     id_temp = new char[n];
     strcpy(id_temp,arg[1]);
 
-    int icompute = modify->find_compute(id_temp);
+    int icompute = modify->find_compute(arg[1]);
     if (icompute < 0) error->all("Could not find fix_modify temp ID");
     temperature = modify->compute[icompute];
 
@@ -793,7 +856,7 @@ int FixNPT::modify_param(int narg, char **arg)
     id_press = new char[n];
     strcpy(id_press,arg[1]);
 
-    int icompute = modify->find_compute(id_press);
+    int icompute = modify->find_compute(arg[1]);
     if (icompute < 0) error->all("Could not find fix_modify press ID");
     pressure = modify->compute[icompute];
 

src/fix_npt.h

@@ -36,7 +36,7 @@ class FixNPT : public Fix {
   void reset_dt();
 
  protected:
-  int dimension;
+  int dimension,which;
   double dtv,dtf,dtq,dthalf;
   double boltz,nktv2p;
   double vol0;

src/fix_nve.cpp

@@ -146,6 +146,9 @@ void FixNVE::initial_integrate_respa(int vflag, int ilevel, int flag)
   dtv = step_respa[ilevel];
   dtf = 0.5 * step_respa[ilevel] * force->ftm2v;
 
+  // innermost level - NVE update of v and x
+  // all other levels - NVE update of v
+
   if (ilevel == 0) initial_integrate(vflag);
   else final_integrate();
 }

src/fix_nvt.cpp

@@ -31,6 +31,8 @@
 
 using namespace LAMMPS_NS;
 
+enum{NOBIAS,BIAS};
+
 /* ---------------------------------------------------------------------- */
 
 FixNVT::FixNVT(LAMMPS *lmp, int narg, char **arg) :
@@ -117,6 +119,9 @@ void FixNVT::init()
   if (icompute < 0) error->all("Temp ID for fix nvt does not exist");
   temperature = modify->compute[icompute];
 
+  if (temperature->tempbias) which = BIAS;
+  else which = NOBIAS;
+
   // set timesteps and frequencies
 
   dtv = update->dt;
@@ -158,7 +163,7 @@ void FixNVT::initial_integrate(int vflag)
   eta += dtv*eta_dot;
   factor = exp(-dthalf*eta_dot);
 
-  // update v and x of only atoms in NVT group
+  // update v and x of only atoms in group
 
   double **x = atom->x;
   double **v = atom->v;
@@ -169,15 +174,32 @@ void FixNVT::initial_integrate(int vflag)
   int nlocal = atom->nlocal;
   if (igroup == atom->firstgroup) nlocal = atom->nfirst;
 
-  for (int i = 0; i < nlocal; i++) {
+  if (which == NOBIAS) {
-    if (mask[i] & groupbit) {
+    for (int i = 0; i < nlocal; i++) {
-      dtfm = dtf / mass[type[i]];
+      if (mask[i] & groupbit) {
-      v[i][0] = v[i][0]*factor + dtfm*f[i][0];
+	dtfm = dtf / mass[type[i]];
-      v[i][1] = v[i][1]*factor + dtfm*f[i][1];
+	v[i][0] = v[i][0]*factor + dtfm*f[i][0];
-      v[i][2] = v[i][2]*factor + dtfm*f[i][2];
+	v[i][1] = v[i][1]*factor + dtfm*f[i][1];
-      x[i][0] += dtv * v[i][0];
+	v[i][2] = v[i][2]*factor + dtfm*f[i][2];
-      x[i][1] += dtv * v[i][1];
+	x[i][0] += dtv * v[i][0];
-      x[i][2] += dtv * v[i][2];
+	x[i][1] += dtv * v[i][1];
+	x[i][2] += dtv * v[i][2];
+      }
+    }
+
+  } else if (which == BIAS) {
+    for (int i = 0; i < nlocal; i++) {
+      if (mask[i] & groupbit) {
+	temperature->remove_bias(i,v[i]);
+	dtfm = dtf / mass[type[i]];
+	v[i][0] = v[i][0]*factor + dtfm*f[i][0];
+	v[i][1] = v[i][1]*factor + dtfm*f[i][1];
+	v[i][2] = v[i][2]*factor + dtfm*f[i][2];
+	temperature->restore_bias(v[i]);
+	x[i][0] += dtv * v[i][0];
+	x[i][1] += dtv * v[i][1];
+	x[i][2] += dtv * v[i][2];
+      }
     }
   }
 }
@@ -188,7 +210,7 @@ void FixNVT::final_integrate()
 {
   double dtfm;
 
-  // update v of only atoms in NVT group
+  // update v of only atoms in group
 
   double **v = atom->v;
   double **f = atom->f;
@@ -198,12 +220,26 @@ void FixNVT::final_integrate()
   int nlocal = atom->nlocal;
   if (igroup == atom->firstgroup) nlocal = atom->nfirst;
 
-  for (int i = 0; i < nlocal; i++) {
+  if (which == NOBIAS) {
-    if (mask[i] & groupbit) {
+    for (int i = 0; i < nlocal; i++) {
-      dtfm = dtf / mass[type[i]] * factor;
+      if (mask[i] & groupbit) {
-      v[i][0] = v[i][0]*factor + dtfm*f[i][0];
+	dtfm = dtf / mass[type[i]] * factor;
-      v[i][1] = v[i][1]*factor + dtfm*f[i][1];
+	v[i][0] = v[i][0]*factor + dtfm*f[i][0];
-      v[i][2] = v[i][2]*factor + dtfm*f[i][2];
+	v[i][1] = v[i][1]*factor + dtfm*f[i][1];
+	v[i][2] = v[i][2]*factor + dtfm*f[i][2];
+      }
+    }
+
+  } else if (which == BIAS) {
+    for (int i = 0; i < nlocal; i++) {
+      if (mask[i] & groupbit) {
+	temperature->remove_bias(i,v[i]);
+	dtfm = dtf / mass[type[i]] * factor;
+	v[i][0] = v[i][0]*factor + dtfm*f[i][0];
+	v[i][1] = v[i][1]*factor + dtfm*f[i][1];
+	v[i][2] = v[i][2]*factor + dtfm*f[i][2];
+	temperature->restore_bias(v[i]);
+      }
     }
   }
 
@@ -242,8 +278,9 @@ void FixNVT::initial_integrate_respa(int vflag, int ilevel, int flag)
   int nlocal = atom->nlocal;
   if (igroup == atom->firstgroup) nlocal = atom->nfirst;
 
-  // outermost level - update eta_dot and apply to v
+  // outermost level - update eta_dot and apply to v with factor
-  // all other levels - NVE update of v
+  // all other levels - NVE update of v (factor = 1)
+  // innermost level - also update x
 
   if (ilevel == nlevels_respa-1) {
     double delta = update->ntimestep - update->beginstep;
@@ -259,19 +296,29 @@ void FixNVT::initial_integrate_respa(int vflag, int ilevel, int flag)
     factor = exp(-dthalf*eta_dot);
   } else factor = 1.0;
 
-  // update v of only atoms in NVT group
+  if (which == NOBIAS) {
+    for (int i = 0; i < nlocal; i++) {
+      if (mask[i] & groupbit) {
+	dtfm = dtf / mass[type[i]];
+	v[i][0] = v[i][0]*factor + dtfm*f[i][0];
+	v[i][1] = v[i][1]*factor + dtfm*f[i][1];
+	v[i][2] = v[i][2]*factor + dtfm*f[i][2];
+      }
+    }
 
-  for (int i = 0; i < nlocal; i++) {
+  } else if (which == BIAS) {
-    if (mask[i] & groupbit) {
+    for (int i = 0; i < nlocal; i++) {
-      dtfm = dtf / mass[type[i]];
+      if (mask[i] & groupbit) {
-      v[i][0] = v[i][0]*factor + dtfm*f[i][0];
+	temperature->remove_bias(i,v[i]);
-      v[i][1] = v[i][1]*factor + dtfm*f[i][1];
+	dtfm = dtf / mass[type[i]];
-      v[i][2] = v[i][2]*factor + dtfm*f[i][2];
+	v[i][0] = v[i][0]*factor + dtfm*f[i][0];
+	v[i][1] = v[i][1]*factor + dtfm*f[i][1];
+	v[i][2] = v[i][2]*factor + dtfm*f[i][2];
+	temperature->restore_bias(v[i]);
+      }
     }
   }
 
-  // innermost level - also update x of only atoms in NVT group
-
   if (ilevel == 0) {
     for (int i = 0; i < nlocal; i++) {
       if (mask[i] & groupbit) {
@@ -287,10 +334,9 @@ void FixNVT::initial_integrate_respa(int vflag, int ilevel, int flag)
 
 void FixNVT::final_integrate_respa(int ilevel)
 {
-  double dtfm;
-
   // set timesteps by level
 
+  double dtfm;
   dtf = 0.5 * step_respa[ilevel] * force->ftm2v;
   dthalf = 0.5 * step_respa[ilevel];
 
@@ -299,9 +345,6 @@ void FixNVT::final_integrate_respa(int ilevel)
 
   if (ilevel == nlevels_respa-1) final_integrate();
   else {
-
-    // update v of only atoms in NVT group
-
     double **v = atom->v;
     double **f = atom->f;
     double *mass = atom->mass;

src/fix_nvt.h

@@ -37,6 +37,7 @@ class FixNVT : public Fix {
   void reset_dt();
 
  protected:
+  int which;
   double t_start,t_stop;
   double t_current,t_target;
   double t_freq,drag,drag_factor;

src/fix_nvt_sllod.cpp

@@ -78,7 +78,7 @@ void FixNVTSlodd::initial_integrate(int vflag)
   eta += dtv*eta_dot;
   factor = exp(-dthalf*eta_dot);
 
-  // update vthermal and x of only atoms in NVT group
+  // update vthermal and x of only atoms in group
   // lamda = 0-1 triclinic lamda coords
   // vstream = streaming velocity = Hrate*lamda + Hratelo
   // vthermal = thermal velocity = v - vstream
@@ -134,7 +134,7 @@ void FixNVTSlodd::final_integrate()
 {
   double dtfm;
 
-  // update vthermal of only atoms in NVT group
+  // update vthermal of only atoms in group
   // lamda = 0-1 triclinic lamda coords
   // vstream = streaming velocity = Hrate*lamda + Hratelo
   // vthermal = thermal velocity = v - vstream
@@ -232,7 +232,7 @@ void FixNVTSlodd::initial_integrate_respa(int vflag, int ilevel, int flag)
     factor = exp(-dthalf*eta_dot);
   } else factor = 1.0;
 
-  // update v of only atoms in NVT group
+  // update v of only atoms in group
 
   double *h_rate = domain->h_rate;
   double *h_ratelo = domain->h_ratelo;
@@ -265,7 +265,7 @@ void FixNVTSlodd::initial_integrate_respa(int vflag, int ilevel, int flag)
     }
   }
 
-  // innermost level - also update x of only atoms in NVT group
+  // innermost level - also update x of only atoms in group
 
   if (ilevel == 0) {
     for (int i = 0; i < nlocal; i++) {

src/fix_temp_rescale.cpp

@@ -28,7 +28,7 @@
 
 using namespace LAMMPS_NS;
 
-enum{STANDARD,REGION,PARTIAL};
+enum{NOBIAS,BIAS};
 
 /* ---------------------------------------------------------------------- */
 
@@ -45,41 +45,11 @@ FixTempRescale::FixTempRescale(LAMMPS *lmp, int narg, char **arg) :
   extscalar = 1;
 
   t_start = atof(arg[4]);
-  t_end = atof(arg[5]);
+  t_stop = atof(arg[5]);
   t_window = atof(arg[6]);
   fraction = atof(arg[7]);
 
-  // optional args
+  // create a new compute temp
-
-  iregion = -1;
-  partial = 0;
-  xflag = yflag = zflag = 1;
-
-  int iarg = 8;
-  while (iarg < narg) {
-    if (strcmp(arg[iarg],"region") == 0) {
-      if (iarg+2 > narg) error->all("Illegal fix temp/rescale command");
-      iregion = domain->find_region(arg[iarg+1]);
-      if (iregion == -1) 
-	error->all("Fix temp/rescale region ID does not exist");
-      iarg += 2;
-    } else if (strcmp(arg[iarg],"partial") == 0) {
-      if (iarg+4 > narg) error->all("Illegal fix temp/rescale command");
-      xflag = atoi(arg[iarg+1]);
-      yflag = atoi(arg[iarg+2]);
-      zflag = atoi(arg[iarg+3]);
-      partial = 1;
-      iarg += 4;
-    } else error->all("Illegal fix temp/rescale command");
-  }
-
-  if (iregion == -1 && partial == 0) type = STANDARD;
-  else if (iregion >= 0 && partial == 0) type = REGION;
-  else if (iregion == -1 && partial) type = PARTIAL;
-  else 
-    error->all("Cannot use both region, partial options in fix temp/rescale");
-
-  // create a new compute temp or temp/region or temp/partial
   // id = fix-ID + temp, compute group = fix group
 
   int n = strlen(id) + 6;
@@ -90,23 +60,8 @@ FixTempRescale::FixTempRescale(LAMMPS *lmp, int narg, char **arg) :
   char **newarg = new char*[6];
   newarg[0] = id_temp;
   newarg[1] = group->names[igroup];
-  if (type == STANDARD) {
+  newarg[2] = (char *) "temp";
-    newarg[2] = (char *) "temp";
+  modify->add_compute(3,newarg);
-    modify->add_compute(3,newarg);
-  } else if (type == REGION) {
-    newarg[2] = (char *) "temp/region";
-    newarg[3] = domain->regions[iregion]->id;
-    modify->add_compute(4,newarg);
-  } else if (type == PARTIAL) {
-    newarg[2] = (char *) "temp/partial";
-    if (xflag) newarg[3] = (char *) "1";
-    else newarg[3] = (char *) "0";
-    if (yflag) newarg[4] = (char *) "1";
-    else newarg[4] = (char *) "0";
-    if (zflag) newarg[5] = (char *) "1";
-    else newarg[5] = (char *) "0";
-    modify->add_compute(6,newarg);
-  }
   delete [] newarg;
   tflag = 1;
 
@@ -141,6 +96,9 @@ void FixTempRescale::init()
   if (icompute < 0) error->all("Temp ID for fix temp/rescale does not exist");
   temperature = modify->compute[icompute];
 
+  if (temperature->tempbias) which = BIAS;
+  else which = NOBIAS;
+
   temperature->init();              // not yet called by Modify::init()
   efactor = (0.5 * force->boltz * temperature->dof);
   energy = 0.0;
@@ -151,20 +109,24 @@ void FixTempRescale::init()
 void FixTempRescale::end_of_step()
 {
   double t_current = temperature->compute_scalar();
+  if (t_current == 0.0)
+    error->all("Computed temperature for fix temp/berendsen cannot be 0.0");
+
   double delta = update->ntimestep - update->beginstep;
   delta /= update->endstep - update->beginstep;
-  double t_target = t_start + delta * (t_end-t_start);
+  double t_target = t_start + delta * (t_stop-t_start);
+
+  // rescale velocity of appropriate atoms if outside window
 
   if (fabs(t_current-t_target) > t_window) {
     t_target = t_current - fraction*(t_current-t_target);
     double factor = sqrt(t_target/t_current);
 
-    double **x = atom->x;
     double **v = atom->v;
     int *mask = atom->mask;
     int nlocal = atom->nlocal;
 
-    if (type == STANDARD) {
+    if (which == NOBIAS) {
       energy += (t_current-t_target) * efactor;
       for (int i = 0; i < nlocal; i++) {
 	if (mask[i] & groupbit) {
@@ -174,25 +136,15 @@ void FixTempRescale::end_of_step()
 	}
       }
 
-    } else if (type == REGION) {
+    } else if (which == BIAS) {
-      efactor = (0.5 * force->boltz * temperature->dof);
-      energy += (t_current-t_target) * efactor;
-      for (int i = 0; i < nlocal; i++) {
-	if (mask[i] & groupbit &&
-	    domain->regions[iregion]->match(x[i][0],x[i][1],x[i][2])) {
-	  v[i][0] *= factor;
-	  v[i][1] *= factor;
-	  v[i][2] *= factor;
-	}
-      }
-
-    } else {
       energy += (t_current-t_target) * efactor;
       for (int i = 0; i < nlocal; i++) {
 	if (mask[i] & groupbit) {
-	  if (xflag) v[i][0] *= factor;
+	  temperature->remove_bias(i,v[i]);
-	  if (yflag) v[i][1] *= factor;
+	  v[i][0] *= factor;
-	  if (zflag) v[i][2] *= factor;
+	  v[i][1] *= factor;
+	  v[i][2] *= factor;
+	  temperature->restore_bias(v[i]);
 	}
       }
     }
@@ -228,6 +180,14 @@ int FixTempRescale::modify_param(int narg, char **arg)
   return 0;
 }
 
+
+/* ---------------------------------------------------------------------- */
+
+void FixTempRescale::reset_target(double t_new)
+{
+  t_start = t_stop = t_new;
+}
+
 /* ---------------------------------------------------------------------- */
 
 double FixTempRescale::compute_scalar()

src/fix_temp_rescale.h

@@ -25,12 +25,13 @@ class FixTempRescale : public Fix {
   int setmask();
   void init();
   void end_of_step();
-  double compute_scalar();
   int modify_param(int, char **);
+  void reset_target(double);
+  double compute_scalar();
 
  private:
-  int type,iregion,partial,xflag,yflag,zflag;
+  int which;
-  double t_start,t_end,t_window;
+  double t_start,t_stop,t_window;
   double fraction,energy,efactor;
 
   char *id_temp;

src/style.h

@@ -180,6 +180,7 @@ DumpStyle(xyz,DumpXYZ)
 #include "fix_spring.h"
 #include "fix_spring_rg.h"
 #include "fix_spring_self.h"
+#include "fix_temp_berendsen.h"
 #include "fix_temp_rescale.h"
 #include "fix_tmd.h"
 #include "fix_viscosity.h"
@@ -233,6 +234,7 @@ FixStyle(SHEAR_HISTORY,FixShearHistory)
 FixStyle(spring,FixSpring)
 FixStyle(spring/rg,FixSpringRG)
 FixStyle(spring/self,FixSpringSelf)
+FixStyle(temp/berendsen,FixTempBerendsen)
 FixStyle(temp/rescale,FixTempRescale)
 FixStyle(tmd,FixTMD)
 FixStyle(viscosity,FixViscosity)

src/temper.cpp

@@ -30,8 +30,6 @@
 #include "output.h"
 #include "thermo.h"
 #include "fix.h"
-#include "fix_nvt.h"
-#include "fix_langevin.h"
 #include "random_park.h"
 #include "finish.h"
 #include "timer.h"
@@ -40,8 +38,6 @@
 
 using namespace LAMMPS_NS;
 
-#define NVT      1
-#define LANGEVIN 2
 // #define TEMPER_DEBUG 1
 
 /* ---------------------------------------------------------------------- */
@@ -97,10 +93,11 @@ void Temper::command(int narg, char **arg)
 
   // fix style must be appropriate for temperature control
 
-  if (strcmp(modify->fix[whichfix]->style,"nvt") == 0) fixstyle = NVT;
+  if ((strcmp(modify->fix[whichfix]->style,"nvt") != 0) &&
-  else if (strcmp(modify->fix[whichfix]->style,"langevin") == 0) 
+      (strcmp(modify->fix[whichfix]->style,"langevin") != 0) &&
-    fixstyle = LANGEVIN;
+      (strcmp(modify->fix[whichfix]->style,"temp/berendsen") != 0) &&
-  else error->universe_all("Tempering fix is not valid");
+      (strcmp(modify->fix[whichfix]->style,"temp/rescale") != 0))
+    error->universe_all("Tempering temperature fix is not valid");
 
   // setup for long tempering run
 
@@ -173,10 +170,7 @@ void Temper::command(int narg, char **arg)
 
   if (narg == 7) {
     double new_temp = set_temp[my_set_temp];
-    if (fixstyle == NVT) 
+    modify->fix[whichfix]->reset_target(new_temp);
-      ((FixNVT *) modify->fix[whichfix])->reset_target(new_temp);
-    else if (fixstyle == LANGEVIN)
-      ((FixLangevin *) modify->fix[whichfix])->reset_target(new_temp);
   }
 
   // setup tempering runs
@@ -278,11 +272,8 @@ void Temper::command(int narg, char **arg)
 
     if (swap) {
       new_temp = set_temp[partner_set_temp];
-      if (fixstyle == NVT) 
+      modify->fix[whichfix]->reset_target(new_temp);
-	((FixNVT *) modify->fix[whichfix])->reset_target(new_temp);
+  }
-      else if (fixstyle == LANGEVIN)
-	((FixLangevin *) modify->fix[whichfix])->reset_target(new_temp);
-    }
 
     // update my_set_temp and temp2world on every proc
     // root procs update their value if swap took place