git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@2351 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/GRANULAR/fix_pour.cpp

@@ -274,8 +274,8 @@ void FixPour::init()
   // check if a shear history fix exists
 
   fix_history = NULL;
-  if (force->pair_match("gran/hooke/history") || 
+  if (force->pair_match("gran/hooke/history",1) || 
-      force->pair_match("gran/hertz/history"))
+      force->pair_match("gran/hertz/history",1))
     for (int i = 0; i < modify->nfix; i++)
       if (strcmp(modify->fix[i]->style,"SHEAR_HISTORY") == 0)
 	fix_history = (FixShearHistory *) modify->fix[i];

src/GRANULAR/fix_wall_gran.cpp

@@ -31,7 +31,7 @@
 using namespace LAMMPS_NS;
 
 enum{XPLANE,YPLANE,ZPLANE,ZCYLINDER};
-enum{NO_HISTORY,HISTORY,HERTZIAN};
+enum{HOOKE,HOOKE_HISTORY,HERTZ_HISTORY};
 
 #define BIG 1.0e20
 
@@ -190,25 +190,17 @@ int FixWallGran::setmask()
 
 void FixWallGran::init()
 {
-  // set local values from Pair values
-
-  if (force->pair == NULL)
-    error->all("Fix wall/gran is incompatible with Pair style");
-  double *p_xkk = (double *) force->pair->extract("xkk");
-  if (!p_xkk)  error->all("Fix wall/gran is incompatible with Pair style");
-  xkk = *p_xkk;
-
-  // same initialization as in pair_gran_history::init_style()
-
-  xkkt = xkk * 2.0/7.0;
-  double gammas = 0.5*gamman;
   dt = update->dt;
 
   // set pairstyle from granular pair style
 
-  if (force->pair_match("gran/no_history")) pairstyle = NO_HISTORY;
+  if (force->pair_match("gran/hooke",1))
-  else if (force->pair_match("gran/history")) pairstyle = HISTORY;
+    pairstyle = HOOKE;
-  else if (force->pair_match("gran/hertzian")) pairstyle = HERTZIAN;
+  else if (force->pair_match("gran/hooke/history",1))
+    pairstyle = HOOKE_HISTORY;
+  else if (force->pair_match("gran/hertz/history",1))
+    pairstyle = HERTZ_HISTORY;
+  else error->all("Fix wall/gran is incompatible with Pair style");
 }
 
 /* ---------------------------------------------------------------------- */
@@ -295,20 +287,20 @@ void FixWallGran::post_force(int vflag)
       rsq = dx*dx + dy*dy + dz*dz;
 
       if (rsq > radius[i]*radius[i]) {
-	if (pairstyle != NO_HISTORY) {
+	if (pairstyle != HOOKE) {
 	  shear[i][0] = 0.0;
 	  shear[i][1] = 0.0;
 	  shear[i][2] = 0.0;
 	}
       } else {
-	if (pairstyle == NO_HISTORY)
+	if (pairstyle == HOOKE)
-	  no_history(rsq,dx,dy,dz,vwall,v[i],f[i],omega[i],torque[i],
+	  hooke(rsq,dx,dy,dz,vwall,v[i],f[i],omega[i],torque[i],
 		radius[i],rmass[i]);
-	else if (pairstyle == HISTORY)
+	else if (pairstyle == HOOKE_HISTORY)
-	  history(rsq,dx,dy,dz,vwall,v[i],f[i],omega[i],torque[i],
+	  hooke_history(rsq,dx,dy,dz,vwall,v[i],f[i],omega[i],torque[i],
 			radius[i],rmass[i],shear[i]);
-	else if (pairstyle == HERTZIAN)
+	else if (pairstyle == HERTZ_HISTORY)
-	  hertzian(rsq,dx,dy,dz,vwall,v[i],f[i],omega[i],torque[i],
+	  hertz_history(rsq,dx,dy,dz,vwall,v[i],f[i],omega[i],torque[i],
 			radius[i],rmass[i],shear[i]);
       }
     }
@@ -317,13 +309,13 @@ void FixWallGran::post_force(int vflag)
 
 /* ---------------------------------------------------------------------- */
 
-void FixWallGran::no_history(double rsq, double dx, double dy, double dz,
+void FixWallGran::hooke(double rsq, double dx, double dy, double dz,
 			double *vwall, double *v,
 			double *f, double *omega, double *torque,
 			double radius, double mass)
 {
   double r,vr1,vr2,vr3,vnnr,vn1,vn2,vn3,vt1,vt2,vt3;
-  double wr1,wr2,wr3,xmeff,damp,ccel,vtr1,vtr2,vtr3,vrel;
+  double wr1,wr2,wr3,meff,damp,ccel,vtr1,vtr2,vtr3,vrel;
   double fn,fs,ft,fs1,fs2,fs3,fx,fy,fz,tor1,tor2,tor3,rinv,rsqinv;
 
   r = sqrt(rsq);
@@ -357,9 +349,9 @@ void FixWallGran::no_history(double rsq, double dx, double dy, double dz,
 
   // normal forces = Hookian contact + normal velocity damping
 
-  xmeff = mass;
+  meff = mass;
-  damp = xmeff*gamman*vnnr*rsqinv;
+  damp = meff*gamman*vnnr*rsqinv;
-  ccel = xkk*(radius-r)*rinv - damp;
+  ccel = kn*(radius-r)*rinv - damp;
 
   // relative velocities
 
@@ -372,7 +364,7 @@ void FixWallGran::no_history(double rsq, double dx, double dy, double dz,
   // force normalization
 
   fn = xmu * fabs(ccel*r);
-  fs = xmeff*gammas*vrel;
+  fs = meff*gammat*vrel;
   if (vrel != 0.0) ft = MIN(fn,fs) / vrel;
   else ft = 0.0;
 
@@ -402,13 +394,13 @@ void FixWallGran::no_history(double rsq, double dx, double dy, double dz,
 
 /* ---------------------------------------------------------------------- */
 
-void FixWallGran::history(double rsq, double dx, double dy, double dz,
+void FixWallGran::hooke_history(double rsq, double dx, double dy, double dz,
 				double *vwall, double *v,
 				double *f, double *omega, double *torque,
 				double radius, double mass, double *shear)
 {
   double r,vr1,vr2,vr3,vnnr,vn1,vn2,vn3,vt1,vt2,vt3;
-  double wr1,wr2,wr3,xmeff,damp,ccel,vtr1,vtr2,vtr3,vrel;
+  double wr1,wr2,wr3,meff,damp,ccel,vtr1,vtr2,vtr3,vrel;
   double fn,fs,fs1,fs2,fs3,fx,fy,fz,tor1,tor2,tor3;
   double shrmag,rsht,rinv,rsqinv;
 
@@ -443,9 +435,9 @@ void FixWallGran::history(double rsq, double dx, double dy, double dz,
 
   // normal forces = Hookian contact + normal velocity damping
 
-  xmeff = mass;
+  meff = mass;
-  damp = xmeff*gamman*vnnr*rsqinv;
+  damp = meff*gamman*vnnr*rsqinv;
-  ccel = xkk*(radius-r)*rinv - damp;
+  ccel = kn*(radius-r)*rinv - damp;
 
   // relative velocities
 
@@ -472,9 +464,9 @@ void FixWallGran::history(double rsq, double dx, double dy, double dz,
 
   // tangential forces = shear + tangential velocity damping
 
-  fs1 = - (xkkt*shear[0] + xmeff*gammas*vtr1);
+  fs1 = - (kt*shear[0] + meff*gammat*vtr1);
-  fs2 = - (xkkt*shear[1] + xmeff*gammas*vtr2);
+  fs2 = - (kt*shear[1] + meff*gammat*vtr2);
-  fs3 = - (xkkt*shear[2] + xmeff*gammas*vtr3);
+  fs3 = - (kt*shear[2] + meff*gammat*vtr3);
 
   // rescale frictional displacements and forces if needed
 
@@ -483,15 +475,15 @@ void FixWallGran::history(double rsq, double dx, double dy, double dz,
 
   if (fs > fn) {
     if (shrmag != 0.0) {
-      shear[0] = (fn/fs) * (shear[0] + xmeff*gammas*vtr1/xkkt) - 
+      shear[0] = (fn/fs) * (shear[0] + meff*gammat*vtr1/kt) - 
-	xmeff*gammas*vtr1/xkkt;
+	meff*gammat*vtr1/kt;
-      shear[1] = (fn/fs) * (shear[1] + xmeff*gammas*vtr2/xkkt) -
+      shear[1] = (fn/fs) * (shear[1] + meff*gammat*vtr2/kt) -
-	xmeff*gammas*vtr2/xkkt;
+	meff*gammat*vtr2/kt;
-      shear[2] = (fn/fs) * (shear[2] + xmeff*gammas*vtr3/xkkt) -
+      shear[2] = (fn/fs) * (shear[2] + meff*gammat*vtr3/kt) -
-	xmeff*gammas*vtr3/xkkt;
+	meff*gammat*vtr3/kt;
-      fs1 = fs1 * fn / fs ;
+      fs1 *= fn/fs ;
-      fs2 = fs2 * fn / fs;
+      fs2 *= fn/fs;
-      fs3 = fs3 * fn / fs;
+      fs3 *= fn/fs;
     } else fs1 = fs2 = fs3 = 0.0;
   }
 
@@ -515,15 +507,15 @@ void FixWallGran::history(double rsq, double dx, double dy, double dz,
 
 /* ---------------------------------------------------------------------- */
 
-void FixWallGran::hertzian(double rsq, double dx, double dy, double dz,
+void FixWallGran::hertz_history(double rsq, double dx, double dy, double dz,
 				double *vwall, double *v,
 				double *f, double *omega, double *torque,
 				double radius, double mass, double *shear)
 {
   double r,vr1,vr2,vr3,vnnr,vn1,vn2,vn3,vt1,vt2,vt3;
-  double wr1,wr2,wr3,xmeff,damp,ccel,vtr1,vtr2,vtr3,vrel;
+  double wr1,wr2,wr3,meff,damp,ccel,vtr1,vtr2,vtr3,vrel;
   double fn,fs,fs1,fs2,fs3,fx,fy,fz,tor1,tor2,tor3;
-  double shrmag,rsht,rhertz,rinv,rsqinv;
+  double shrmag,rsht,polyhertz,rinv,rsqinv;
 
   r = sqrt(rsq);
   rinv = 1.0/r;
@@ -556,11 +548,11 @@ void FixWallGran::hertzian(double rsq, double dx, double dy, double dz,
 
   // normal forces = Hertzian contact + normal velocity damping
 
-  xmeff = mass;
+  meff = mass;
-  damp = xmeff*gamman*vnnr*rsqinv;
+  damp = meff*gamman*vnnr*rsqinv;
-  ccel = xkk*(radius-r)*rinv - damp;
+  ccel = kn*(radius-r)*rinv - damp;
-  rhertz = sqrt(radius - r);
+  polyhertz = sqrt((radius-r)*radius);
-  ccel = rhertz * ccel;
+  ccel *= polyhertz;
 
   // relative velocities
 
@@ -587,9 +579,9 @@ void FixWallGran::hertzian(double rsq, double dx, double dy, double dz,
 
   // tangential forces = shear + tangential velocity damping
 
-  fs1 = -rhertz * (xkkt*shear[0] + xmeff*gammas*vtr1);
+  fs1 = -polyhertz * (kt*shear[0] + meff*gammat*vtr1);
-  fs2 = -rhertz * (xkkt*shear[1] + xmeff*gammas*vtr2);
+  fs2 = -polyhertz * (kt*shear[1] + meff*gammat*vtr2);
-  fs3 = -rhertz * (xkkt*shear[2] + xmeff*gammas*vtr3);
+  fs3 = -polyhertz * (kt*shear[2] + meff*gammat*vtr3);
 
   // rescale frictional displacements and forces if needed
 
@@ -598,15 +590,15 @@ void FixWallGran::hertzian(double rsq, double dx, double dy, double dz,
 
   if (fs > fn) {
     if (shrmag != 0.0) {
-      shear[0] = (fn/fs) * (shear[0] + xmeff*gammas*vtr1/xkkt) - 
+      shear[0] = (fn/fs) * (shear[0] + meff*gammat*vtr1/kt) - 
-	xmeff*gammas*vtr1/xkkt;
+	meff*gammat*vtr1/kt;
-      shear[1] = (fn/fs) * (shear[1] + xmeff*gammas*vtr2/xkkt) -
+      shear[1] = (fn/fs) * (shear[1] + meff*gammat*vtr2/kt) -
-	xmeff*gammas*vtr2/xkkt;
+	meff*gammat*vtr2/kt;
-      shear[2] = (fn/fs) * (shear[2] + xmeff*gammas*vtr3/xkkt) -
+      shear[2] = (fn/fs) * (shear[2] + meff*gammat*vtr3/kt) -
-	xmeff*gammas*vtr3/xkkt;
+	meff*gammat*vtr3/kt;
-      fs1 = fs1 * fn / fs ;
+      fs1 *= fn/fs ;
-      fs2 = fs2 * fn / fs;
+      fs2 *= fn/fs;
-      fs3 = fs3 * fn / fs;
+      fs3 *= fn/fs;
     } else fs1 = fs2 = fs3 = 0.0;
   }
 

src/GRANULAR/fix_wall_gran.h

@@ -40,7 +40,7 @@ class FixWallGran : public Fix {
 
  private:
   int wallstyle,pairstyle,wiggle,wshear,axis;
-  double xkk,xkkt,gamman,gammas,xmu;
+  double kn,kt,gamman,gammat,xmu;
   double lo,hi,cylradius;
   double dt;
   double amplitude,period,omega,time_origin,vshear;
@@ -48,12 +48,12 @@ class FixWallGran : public Fix {
   int *touch;
   double **shear;
 
-  void no_history(double, double, double, double, double *,
+  void hooke(double, double, double, double, double *,
 	     double *, double *, double *, double *, double, double);
-  void history(double, double, double, double, double *,
+  void hooke_history(double, double, double, double, double *,
 		     double *, double *, double *, double *, double, double,
 		     double *);
-  void hertzian(double, double, double, double, double *,
+  void hertz_history(double, double, double, double, double *,
 		     double *, double *, double *, double *, double, double,
 		     double *);
 };

src/GRANULAR/pair_gran_hertz_history.cpp

@@ -16,12 +16,14 @@
 ------------------------------------------------------------------------- */
 
 #include "math.h"
+#include "stdlib.h"
 #include "stdio.h"
 #include "string.h"
 #include "pair_gran_hertz_history.h"
 #include "atom.h"
 #include "force.h"
 #include "neigh_list.h"
+#include "error.h"
 
 using namespace LAMMPS_NS;
 
@@ -47,9 +49,9 @@ void PairGranHertzHistory::compute(int eflag, int vflag)
   double vr1,vr2,vr3,vnnr,vn1,vn2,vn3,vt1,vt2,vt3;
   double wr1,wr2,wr3;
   double vtr1,vtr2,vtr3,vrel;
-  double xmeff,damp,ccel,tor1,tor2,tor3;
+  double meff,damp,ccel,tor1,tor2,tor3;
   double fn,fs,fs1,fs2,fs3;
-  double shrmag,rsht,rhertz;
+  double shrmag,rsht,polyhertz;
   int *ilist,*jlist,*numneigh,**firstneigh;
   int *touch,**firsttouch;
   double *shear,*allshear,**firstshear;
@@ -139,13 +141,13 @@ void PairGranHertzHistory::compute(int eflag, int vflag)
 
 	// normal force = Hertzian contact + normal velocity damping
 
-	xmeff = rmass[i]*rmass[j] / (rmass[i]+rmass[j]);
+	meff = rmass[i]*rmass[j] / (rmass[i]+rmass[j]);
-	if (mask[i] & freeze_group_bit) xmeff = rmass[j];
+	if (mask[i] & freeze_group_bit) meff = rmass[j];
-	if (mask[j] & freeze_group_bit) xmeff = rmass[i];
+	if (mask[j] & freeze_group_bit) meff = rmass[i];
-	damp = xmeff*gamman*vnnr*rsqinv;
+	damp = meff*gamman*vnnr*rsqinv;
-	ccel = xkk*(radsum-r)*rinv - damp;
+	ccel = kn*(radsum-r)*rinv - damp;
-	rhertz = sqrt(radsum - r);
+	polyhertz = sqrt((radsum-r)*radi*radj / radsum);
-	ccel *= rhertz;
+	ccel *= polyhertz;
 
 	// relative velocities
 
@@ -175,9 +177,9 @@ void PairGranHertzHistory::compute(int eflag, int vflag)
 
 	// tangential forces = shear + tangential velocity damping
 
-        fs1 = -rhertz * (xkkt*shear[0] + xmeff*gammas*vtr1);
+        fs1 = -polyhertz * (kt*shear[0] + meff*gammat*vtr1);
-        fs2 = -rhertz * (xkkt*shear[1] + xmeff*gammas*vtr2);
+        fs2 = -polyhertz * (kt*shear[1] + meff*gammat*vtr2);
-        fs3 = -rhertz * (xkkt*shear[2] + xmeff*gammas*vtr3);
+        fs3 = -polyhertz * (kt*shear[2] + meff*gammat*vtr3);
 
 	// rescale frictional displacements and forces if needed
 
@@ -186,20 +188,16 @@ void PairGranHertzHistory::compute(int eflag, int vflag)
 
 	if (fs > fn) {
 	  if (shrmag != 0.0) {
-	    shear[0] = (fn/fs) * (shear[0] + xmeff*gammas*vtr1/xkkt) -
+	    shear[0] = (fn/fs) * (shear[0] + meff*gammat*vtr1/kt) -
-	      xmeff*gammas*vtr1/xkkt;
+	      meff*gammat*vtr1/kt;
-	    shear[1] = (fn/fs) * (shear[1] + xmeff*gammas*vtr2/xkkt) -
+	    shear[1] = (fn/fs) * (shear[1] + meff*gammat*vtr2/kt) -
-	      xmeff*gammas*vtr2/xkkt;
+	      meff*gammat*vtr2/kt;
-	    shear[2] = (fn/fs) * (shear[2] + xmeff*gammas*vtr3/xkkt) -
+	    shear[2] = (fn/fs) * (shear[2] + meff*gammat*vtr3/kt) -
-	      xmeff*gammas*vtr3/xkkt;
+	      meff*gammat*vtr3/kt;
 	    fs1 *= fn/fs;
 	    fs2 *= fn/fs;
 	    fs3 *= fn/fs;
-	  } else {
+	  } else fs1 = fs2 = fs3 = 0.0;
-	    fs1 = 0.0;
-	    fs2 = 0.0;
-	    fs3 = 0.0;
-	  }
 	}
 
 	// forces & torques
@@ -233,3 +231,33 @@ void PairGranHertzHistory::compute(int eflag, int vflag)
     }
   }
 }
+
+/* ----------------------------------------------------------------------
+   global settings
+------------------------------------------------------------------------- */
+
+void PairGranHertzHistory::settings(int narg, char **arg)
+{
+  if (narg != 6) error->all("Illegal pair_style command");
+
+  kn = atof(arg[0]);
+  if (strcmp(arg[1],"NULL") == 0) kt = kn * 2.0/7.0;
+  else kt = atof(arg[1]);
+
+  gamman = atof(arg[2]);
+  if (strcmp(arg[3],"NULL") == 0) gammat = 0.5 * gamman;
+  else gammat = atof(arg[3]);
+
+  xmu = atof(arg[4]);
+  dampflag = atoi(arg[5]);
+  if (dampflag == 0) gammat = 0.0;
+
+  if (kn < 0.0 || kt < 0.0 || gamman < 0.0 || gammat < 0.0 || 
+      xmu < 0.0 || xmu > 1.0 || dampflag < 0 || dampflag > 1)
+    error->all("Illegal pair_style command");
+
+  // convert Kn and Kt from pressure units to force/distance^2
+
+  kn /= force->nktv2p;
+  kt /= force->nktv2p;
+}

src/GRANULAR/pair_gran_hertz_history.h

@@ -22,6 +22,7 @@ class PairGranHertzHistory : public PairGranHookeHistory {
  public:
   PairGranHertzHistory(class LAMMPS *);
   void compute(int, int);
+  void settings(int, char **);
 };
 
 }

src/GRANULAR/pair_gran_hooke.cpp

@@ -45,7 +45,7 @@ void PairGranHooke::compute(int eflag, int vflag)
   double vr1,vr2,vr3,vnnr,vn1,vn2,vn3,vt1,vt2,vt3;
   double wr1,wr2,wr3;
   double vtr1,vtr2,vtr3,vrel;
-  double xmeff,damp,ccel,tor1,tor2,tor3;
+  double meff,damp,ccel,tor1,tor2,tor3;
   double fn,fs,ft,fs1,fs2,fs3;
   int *ilist,*jlist,*numneigh,**firstneigh;
 
@@ -121,11 +121,11 @@ void PairGranHooke::compute(int eflag, int vflag)
 
 	// normal forces = Hookian contact + normal velocity damping
 
-	xmeff = rmass[i]*rmass[j] / (rmass[i]+rmass[j]);
+	meff = rmass[i]*rmass[j] / (rmass[i]+rmass[j]);
-	if (mask[i] & freeze_group_bit) xmeff = rmass[j];
+	if (mask[i] & freeze_group_bit) meff = rmass[j];
-	if (mask[j] & freeze_group_bit) xmeff = rmass[i];
+	if (mask[j] & freeze_group_bit) meff = rmass[i];
-	damp = xmeff*gamman*vnnr*rsqinv;
+	damp = meff*gamman*vnnr*rsqinv;
-	ccel = xkk*(radsum-r)*rinv - damp;
+	ccel = kn*(radsum-r)*rinv - damp;
 
 	// relative velocities
 
@@ -138,7 +138,7 @@ void PairGranHooke::compute(int eflag, int vflag)
 	// force normalization
 
 	fn = xmu * fabs(ccel*r);
-	fs = xmeff*gammas*vrel;
+	fs = meff*gammat*vrel;
 	if (vrel != 0.0) ft = MIN(fn,fs) / vrel;
 	else ft = 0.0;
 

src/GRANULAR/pair_gran_hooke_history.cpp

@@ -73,7 +73,7 @@ void PairGranHookeHistory::compute(int eflag, int vflag)
   double vr1,vr2,vr3,vnnr,vn1,vn2,vn3,vt1,vt2,vt3;
   double wr1,wr2,wr3;
   double vtr1,vtr2,vtr3,vrel;
-  double xmeff,damp,ccel,tor1,tor2,tor3;
+  double meff,damp,ccel,tor1,tor2,tor3;
   double fn,fs,fs1,fs2,fs3;
   double shrmag,rsht;
   int *ilist,*jlist,*numneigh,**firstneigh;
@@ -165,11 +165,11 @@ void PairGranHookeHistory::compute(int eflag, int vflag)
 
 	// normal forces = Hookian contact + normal velocity damping
 
-	xmeff = rmass[i]*rmass[j] / (rmass[i]+rmass[j]);
+	meff = rmass[i]*rmass[j] / (rmass[i]+rmass[j]);
-	if (mask[i] & freeze_group_bit) xmeff = rmass[j];
+	if (mask[i] & freeze_group_bit) meff = rmass[j];
-	if (mask[j] & freeze_group_bit) xmeff = rmass[i];
+	if (mask[j] & freeze_group_bit) meff = rmass[i];
-	damp = xmeff*gamman*vnnr*rsqinv;
+	damp = meff*gamman*vnnr*rsqinv;
-	ccel = xkk*(radsum-r)*rinv - damp;
+	ccel = kn*(radsum-r)*rinv - damp;
 
 	// relative velocities
 
@@ -199,9 +199,9 @@ void PairGranHookeHistory::compute(int eflag, int vflag)
 
 	// tangential forces = shear + tangential velocity damping
 
-	fs1 = - (xkkt*shear[0] + xmeff*gammas*vtr1);
+	fs1 = - (kt*shear[0] + meff*gammat*vtr1);
-	fs2 = - (xkkt*shear[1] + xmeff*gammas*vtr2);
+	fs2 = - (kt*shear[1] + meff*gammat*vtr2);
-	fs3 = - (xkkt*shear[2] + xmeff*gammas*vtr3);
+	fs3 = - (kt*shear[2] + meff*gammat*vtr3);
 
 	// rescale frictional displacements and forces if needed
 
@@ -210,20 +210,16 @@ void PairGranHookeHistory::compute(int eflag, int vflag)
 
 	if (fs > fn) {
 	  if (shrmag != 0.0) {
-	    shear[0] = (fn/fs) * (shear[0] + xmeff*gammas*vtr1/xkkt) -
+	    shear[0] = (fn/fs) * (shear[0] + meff*gammat*vtr1/kt) -
-	      xmeff*gammas*vtr1/xkkt;
+	      meff*gammat*vtr1/kt;
-	    shear[1] = (fn/fs) * (shear[1] + xmeff*gammas*vtr2/xkkt) -
+	    shear[1] = (fn/fs) * (shear[1] + meff*gammat*vtr2/kt) -
-	      xmeff*gammas*vtr2/xkkt;
+	      meff*gammat*vtr2/kt;
-	    shear[2] = (fn/fs) * (shear[2] + xmeff*gammas*vtr3/xkkt) -
+	    shear[2] = (fn/fs) * (shear[2] + meff*gammat*vtr3/kt) -
-	      xmeff*gammas*vtr3/xkkt;
+	      meff*gammat*vtr3/kt;
 	    fs1 *= fn/fs;
 	    fs2 *= fn/fs;
 	    fs3 *= fn/fs;
-	  } else {
+	  } else fs1 = fs2 = fs3 = 0.0;
-	    fs1 = 0.0;
-	    fs2 = 0.0;
-	    fs3 = 0.0;
-	  }
 	}
 
 	// forces & torques
@@ -281,12 +277,23 @@ void PairGranHookeHistory::allocate()
 
 void PairGranHookeHistory::settings(int narg, char **arg)
 {
-  if (narg != 4) error->all("Illegal pair_style command");
+  if (narg != 6) error->all("Illegal pair_style command");
 
-  xkk = atof(arg[0]);
+  kn = atof(arg[0]);
-  gamman = atof(arg[1]);
+  if (strcmp(arg[1],"NULL") == 0) kt = kn * 2.0/7.0;
-  xmu = atof(arg[2]);
+  else kt = atof(arg[1]);
-  dampflag = atoi(arg[3]);
+
+  gamman = atof(arg[2]);
+  if (strcmp(arg[3],"NULL") == 0) gammat = 0.5 * gamman;
+  else gammat = atof(arg[3]);
+
+  xmu = atof(arg[4]);
+  dampflag = atoi(arg[5]);
+  if (dampflag == 0) gammat = 0.0;
+
+  if (kn < 0.0 || kt < 0.0 || gamman < 0.0 || gammat < 0.0 || 
+      xmu < 0.0 || xmu > 1.0 || dampflag < 0 || dampflag > 1)
+    error->all("Illegal pair_style command");
 }
 
 /* ----------------------------------------------------------------------
@@ -339,9 +346,6 @@ void PairGranHookeHistory::init_style()
     neighbor->requests[irequest]->dnum = 3;
   }
 
-  xkkt = xkk * 2.0/7.0;
-  double gammas = 0.5*gamman;
-  if (dampflag == 0) gammas = 0.0;
   dt = update->dt;
 
   // if shear history is stored:
@@ -466,8 +470,10 @@ void PairGranHookeHistory::read_restart(FILE *fp)
 
 void PairGranHookeHistory::write_restart_settings(FILE *fp)
 {
-  fwrite(&xkk,sizeof(double),1,fp);
+  fwrite(&kn,sizeof(double),1,fp);
+  fwrite(&kt,sizeof(double),1,fp);
   fwrite(&gamman,sizeof(double),1,fp);
+  fwrite(&gammat,sizeof(double),1,fp);
   fwrite(&xmu,sizeof(double),1,fp);
   fwrite(&dampflag,sizeof(int),1,fp);
 }
@@ -479,30 +485,23 @@ void PairGranHookeHistory::write_restart_settings(FILE *fp)
 void PairGranHookeHistory::read_restart_settings(FILE *fp)
 {
   if (comm->me == 0) {
-    fread(&xkk,sizeof(double),1,fp);
+    fread(&kn,sizeof(double),1,fp);
+    fread(&kt,sizeof(double),1,fp);
     fread(&gamman,sizeof(double),1,fp);
+    fread(&gammat,sizeof(double),1,fp);
     fread(&xmu,sizeof(double),1,fp);
     fread(&dampflag,sizeof(int),1,fp);
   }
-  MPI_Bcast(&xkk,1,MPI_DOUBLE,0,world);
+  MPI_Bcast(&kn,1,MPI_DOUBLE,0,world);
+  MPI_Bcast(&kt,1,MPI_DOUBLE,0,world);
   MPI_Bcast(&gamman,1,MPI_DOUBLE,0,world);
+  MPI_Bcast(&gammat,1,MPI_DOUBLE,0,world);
   MPI_Bcast(&xmu,1,MPI_DOUBLE,0,world);
   MPI_Bcast(&dampflag,1,MPI_INT,0,world);
 }
 
 /* ---------------------------------------------------------------------- */
 
-void *PairGranHookeHistory::extract(char *str)
-{
-  if (strcmp(str,"xkk") == 0) return (void *) &xkk;
-  else if (strcmp(str,"gamman") == 0) return (void *) &gamman;
-  else if (strcmp(str,"xmu") == 0) return (void *) &xmu;
-  else if (strcmp(str,"dampflag") == 0) return (void *) &dampflag;
-  return NULL;
-}
-
-/* ---------------------------------------------------------------------- */
-
 void PairGranHookeHistory::reset_dt()
 {
   dt = update->dt;

src/GRANULAR/pair_gran_hooke_history.h

@@ -23,7 +23,7 @@ class PairGranHookeHistory : public Pair {
   PairGranHookeHistory(class LAMMPS *);
   ~PairGranHookeHistory();
   virtual void compute(int, int);
-  void settings(int, char **);
+  virtual void settings(int, char **);
   void coeff(int, char **);
   void init_style();
   void init_list(int, class NeighList *);
@@ -32,13 +32,11 @@ class PairGranHookeHistory : public Pair {
   void read_restart(FILE *);
   void write_restart_settings(FILE *);
   void read_restart_settings(FILE *);
-  void *extract(char *);
   void reset_dt();
 
  protected:
-  double xkk,xkkt,xmu;
+  double kn,kt,gamman,gammat,xmu;
   int dampflag;
-  double gamman,gammas;
   double dt;
   int freeze_group_bit;
   int history;

src/PERI/fix_peri_neigh.cpp

@@ -143,7 +143,7 @@ void FixPeriNeigh::setup(int vflag)
 
   // scan neighbor list to set maxpartner
 
-  Pair *anypair = force->pair_match("peri");
+  Pair *anypair = force->pair_match("peri",0);
   double **cutsq = anypair->cutsq;
 
   for (ii = 0; ii < inum; ii++) {

src/force.cpp

@@ -152,23 +152,30 @@ Pair *Force::new_pair(const char *style)
 }
 
 /* ----------------------------------------------------------------------
-   return ptr to current pair class or hybrid sub-class if it contains word
+   return ptr to current pair class or hybrid sub-class
+   if exact, then style name must be exact match to word
+   if not exact, style name must contain word
    else return NULL
 ------------------------------------------------------------------------- */
 
-Pair *Force::pair_match(const char *word)
+Pair *Force::pair_match(const char *word, int exact)
 {
-  if (strstr(pair_style,word)) return pair;
+  if (exact && strcmp(pair_style,word) == 0) return pair;
+  else if (!exact && strstr(pair_style,word)) return pair;
   else if (strcmp(pair_style,"hybrid") == 0) {
     PairHybrid *hybrid = (PairHybrid *) pair;
     for (int i = 0; i < hybrid->nstyles; i++) {
-      if (strstr(hybrid->keywords[i],word))
+      if (exact && strcmp(hybrid->keywords[i],word) == 0)
+	return hybrid->styles[i];
+      else if (!exact && strstr(hybrid->keywords[i],word))
 	return hybrid->styles[i];
     }
   } else if (strcmp(pair_style,"hybrid/overlay") == 0) {
     PairHybridOverlay *hybrid = (PairHybridOverlay *) pair;
     for (int i = 0; i < hybrid->nstyles; i++) {
-      if (strstr(hybrid->keywords[i],word))
+      if (exact && strcmp(hybrid->keywords[i],word) == 0)
+	return hybrid->styles[i];
+      else if (!exact && strstr(hybrid->keywords[i],word))
 	return hybrid->styles[i];
     }
   }

src/force.h

@@ -62,7 +62,7 @@ class Force : protected Pointers {
 
   void create_pair(const char *);
   class Pair *new_pair(const char *);
-  class Pair *pair_match(const char *);
+  class Pair *pair_match(const char *, int);
 
   void create_bond(const char *);
   class Bond *new_bond(const char *);

src/pair.cpp

@@ -792,18 +792,18 @@ void Pair::write_file(int narg, char **arg)
 
   // if pair style = soft, set prefactor to final value
 
-  Pair *spair = force->pair_match("soft");
+  Pair *spair = force->pair_match("soft",1);
   if (spair)
     ((PairSoft *) spair)->prefactor[itype][jtype] =
       ((PairSoft *) spair)->prestop[itype][jtype];
 
-  // if pair style = EAM, swap in dummy fp vector
+  // if pair style = any of EAM, swap in dummy fp vector
 
   double eamfp[2];
   eamfp[0] = eamfp[1] = 0.0;
   double *eamfp_hold;
 
-  Pair *epair = force->pair_match("eam");
+  Pair *epair = force->pair_match("eam",0);
   if (epair) epair->swap_eam(eamfp,&eamfp_hold);
 
   // if atom style defines charge, swap in dummy q vec