--- trunk/OOPSE/libmdtools/ZConstraint.cpp	2003/08/13 19:21:53	693
+++ trunk/OOPSE/libmdtools/ZConstraint.cpp	2003/08/15 19:24:13	699
@@ -2,8 +2,8 @@ template<typename T> ZConstraint<T>::ZConstraint(SimIn
 #include "simError.h"
 #include <cmath>
 template<typename T> ZConstraint<T>::ZConstraint(SimInfo* theInfo, ForceFields* the_ff) 
-                                    : T(theInfo, the_ff), fz(NULL), 
-				      indexOfZConsMols(NULL)
+                                    : T(theInfo, the_ff), fz(NULL), curZPos(NULL),
+				                         indexOfZConsMols(NULL), forcePolicy(NULL), curZconsTime(0)
 {
 
   //get properties from SimInfo
@@ -11,6 +11,7 @@ template<typename T> ZConstraint<T>::ZConstraint(SimIn
   ZConsParaData* zConsParaData;
   DoubleData* sampleTime;
   DoubleData* tolerance;
+  StringData* policy;
   StringData* filename; 
   double COM[3];
 
@@ -25,6 +26,46 @@ template<typename T> ZConstraint<T>::ZConstraint(SimIn
   
   double halfOfLargestBox = max(info->boxL[0], max(info->boxL[1], info->boxL[2])) /2;
   zForceConst = Kb * info->target_temp /(halfOfLargestBox * halfOfLargestBox);
+
+  //creat force substraction policy
+  data = info->getProperty(ZCONSFORCEPOLICY_ID);
+  if(!data){
+    sprintf( painCave.errMsg,
+               "ZConstraint Warning: User does not set force substraction policy, "
+               "average force substraction policy is used\n");
+    painCave.isFatal = 0;
+    simError();      
+
+    forcePolicy = (ForceSubstractionPolicy*) new PolicyByNumber(this);
+  }
+  else{
+    policy = dynamic_cast<StringData*>(data);
+		
+	 if(!policy){
+      sprintf( painCave.errMsg,
+                 "ZConstraint Error: Convertion from GenericData to StringData failure, "
+                 "average force substraction policy is used\n");
+      painCave.isFatal = 0;
+      simError();      
+
+      forcePolicy = (ForceSubstractionPolicy*) new PolicyByNumber(this);
+	 }
+	 else{
+	 	if(policy->getData() == "BYNUMBER")
+         forcePolicy = (ForceSubstractionPolicy*) new PolicyByNumber(this);
+	 	else if(policy->getData() == "BYMASS")
+         forcePolicy = (ForceSubstractionPolicy*) new PolicyByMass(this);
+		else{
+        sprintf( painCave.errMsg,
+                  "ZConstraint Warning: unknown force substraction policy, "
+                  "average force substraction policy is used\n");
+        painCave.isFatal = 0;
+        simError();      
+	   }	 	
+	 }
+  }
+	
+  
 
   //retrieve sample time of z-contraint 
   data = info->getProperty(ZCONSTIME_ID);
@@ -238,6 +279,7 @@ template<typename T> ZConstraint<T>::ZConstraint(SimIn
       massOfZConsMols.push_back(molecules[i].getTotalMass());  
 
       zPos.push_back((*parameters)[searchResult].zPos);
+		cout << "index: "<< (*parameters)[searchResult].zconsIndex <<"\tzPos = " << (*parameters)[searchResult].zPos << endl; 
 	   kz.push_back((*parameters)[searchResult]. kRatio * zForceConst);
       
       molecules[i].getCOM(COM);
@@ -252,9 +294,10 @@ template<typename T> ZConstraint<T>::ZConstraint(SimIn
   }
 
   fz = new double[zconsMols.size()];
+  curZPos = new double[zconsMols.size()]; 
   indexOfZConsMols = new int [zconsMols.size()];
 
-  if(!fz || !indexOfZConsMols){
+  if(!fz || !curZPos || !indexOfZConsMols){
     sprintf( painCave.errMsg,
              "Memory allocation failure in class Zconstraint\n");
     painCave.isFatal = 1;
@@ -284,7 +327,7 @@ template<typename T> ZConstraint<T>::ZConstraint(SimIn
 #ifndef IS_MPI
   totalMassOfUncons = totalMassOfUncons_local;
 #else
-  MPI_Allreduce(&totalMassOfUncons_local, &totalMassOfUncons, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);  
+  MPI_Allreduce(&totalMassOfUncons_local, &totalMassOfUncons, 1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);  
 #endif
 
 
@@ -297,11 +340,11 @@ template<typename T> ZConstraint<T>::ZConstraint(SimIn
 #ifndef IS_MPI
   totNumOfUnconsAtoms = nUnconsAtoms_local;
 #else
-  MPI_Allreduce(&nUnconsAtoms_local, &totNumOfUnconsAtoms, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);  
+  MPI_Allreduce(&nUnconsAtoms_local, &totNumOfUnconsAtoms, 1, MPI_INT,MPI_SUM, MPI_COMM_WORLD);  
 #endif  
 
   // creat zconsWriter  
-  fzOut = new ZConsWriter(zconsOutput.c_str());   
+  fzOut = new ZConsWriter(zconsOutput.c_str(), parameters);   
   
   if(!fzOut){
     sprintf( painCave.errMsg,
@@ -309,19 +352,26 @@ template<typename T> ZConstraint<T>::ZConstraint(SimIn
     painCave.isFatal = 1;
     simError();
   }
-  
+
+  forcePolicy->update();
 }
 
 template<typename T> ZConstraint<T>::~ZConstraint()
 {
   if(fz)
     delete[] fz;
+
+  if(curZPos)
+    delete[] curZPos;
   
   if(indexOfZConsMols)
     delete[] indexOfZConsMols;
   
   if(fzOut)
     delete fzOut;
+	
+  if(forcePolicy)
+    delete forcePolicy;
 }
 
 #ifdef IS_MPI
@@ -377,15 +427,19 @@ template<typename T> void ZConstraint<T>::update()
   // that we want to make the MPI communication simple
   if(fz)
     delete[] fz;
+	
+  if(curZPos)
+    delete[] curZPos;
     
   if(indexOfZConsMols)
     delete[] indexOfZConsMols;
     
   if (zconsMols.size() > 0){
     fz = new double[zconsMols.size()];
+	 curZPos = new double[zconsMols.size()];
     indexOfZConsMols =  new int[zconsMols.size()];
     
-    if(!fz || !indexOfZConsMols){
+    if(!fz || !curZPos || !indexOfZConsMols){
       sprintf( painCave.errMsg,
                "Memory allocation failure in class Zconstraint\n");
       painCave.isFatal = 1;
@@ -399,8 +453,12 @@ template<typename T> void ZConstraint<T>::update()
   }
   else{
     fz = NULL;
+	 curZPos = NULL;
     indexOfZConsMols = NULL;
   }
+	
+  //
+  forcePolicy->update();
   
 }
 
@@ -456,35 +514,60 @@ template<typename T> void ZConstraint<T>::integrate(){
  *
  *
  *
- */
-
- 
+ */ 
 template<typename T> void ZConstraint<T>::calcForce(int calcPot, int calcStress){
   double zsys;
+  double COM[3];
+  double force[3];
 
   T::calcForce(calcPot, calcStress);
 
-  if (checkZConsState())
-  zeroOutVel();
-  
+  if (checkZConsState()){
+    zeroOutVel();
+	 forcePolicy->update();
+  }  
   zsys = calcZSys();
   cout << "---------------------------------------------------------------------" <<endl;
-  cout << "current time: " << info->getTime() <<"\tcenter of mass at z: " << zsys << endl;   	 
-  cout << "before calcForce, the COMVel of unconstraint molecules is " << calcCOMVel() <<endl;
-	
+  cout << "current time: " << info->getTime() << endl;
+  cout << "center of mass at z: " << zsys << endl;   	 
+  //cout << "before calcForce, the COMVel of moving molecules is " << calcMovingMolsCOMVel() <<endl;
+  cout << "before calcForce, the COMVel of system is " << calcSysCOMVel() <<endl;
 
+  //cout <<	 "before doZConstraintForce, totalForce is " << calcTotalForce() << endl;
+
   //do zconstraint force; 
   if (haveFixedZMols())
     this->doZconstraintForce();
-
-
-      
+     
   //use harmonical poteintial to move the molecules to the specified positions
   if (haveMovingZMols())
     this->doHarmonic();
-   
-  fzOut->writeFZ(info->getTime(), zconsMols.size(),indexOfZConsMols, fz);
-  cout << "after calcForce, the COMVel of unconstraint molecules is " << calcCOMVel() <<endl; 
+
+  //cout <<	 "after doHarmonic, totalForce is " << calcTotalForce() << endl;
+
+  //write out forces and current positions of z-constraint molecules
+  if(info->getTime() >= curZconsTime){		
+	 for(int i = 0; i < zconsMols.size(); i++){
+      zconsMols[i]->getCOM(COM);
+		curZPos[i] = COM[whichDirection];
+
+		//if the z-constraint molecule is still moving, just record its force
+		if(states[i] == zcsMoving){
+         fz[i] = 0;
+		  Atom** movingZAtoms;
+		  movingZAtoms = zconsMols[i]->getMyAtoms();
+		  for(int j = 0; j < zconsMols[i]->getNAtoms(); j++){
+           movingZAtoms[j]->getFrc(force);
+           fz[i] += force[whichDirection];
+		  }
+	   }
+	 }
+    fzOut->writeFZ(info->getTime(), zconsMols.size(), indexOfZConsMols, fz, curZPos);
+	 curZconsTime += zconsTime;
+  }
+	
+  //cout << "after calcForce, the COMVel of moving molecules is " << calcMovingMolsCOMVel() <<endl; 
+  cout << "after calcForce, the COMVel of system is " << calcSysCOMVel() <<endl; 
 }
  
 template<typename T> double ZConstraint<T>::calcZSys()
@@ -494,16 +577,11 @@ template<typename T> double ZConstraint<T>::calcZSys()
   double totalMass;
   double totalMZ_local;
   double totalMZ;
-  double massOfUncons_local;
   double massOfCurMol;
   double COM[3];
-  
+	
   totalMass_local = 0;
-  totalMass = 0;
   totalMZ_local = 0;
-  totalMZ = 0;
-  massOfUncons_local = 0;
-    
   
   for(int i = 0; i < nMols; i++){
     massOfCurMol = molecules[i].getTotalMass(); 
@@ -511,24 +589,17 @@ template<typename T> double ZConstraint<T>::calcZSys()
      
     totalMass_local += massOfCurMol;
     totalMZ_local += massOfCurMol * COM[whichDirection];
-    
-    if(isZConstraintMol(&molecules[i]) == -1){
-    
-      massOfUncons_local += massOfCurMol;
-    }  
-    
+
   }
+ 
   
-  
 #ifdef IS_MPI  
-  MPI_Allreduce(&totalMass_local, &totalMass, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
-  MPI_Allreduce(&totalMZ_local, &totalMZ, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);  
-  MPI_Allreduce(&massOfUncons_local, &totalMassOfUncons, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
-#else
+  MPI_Allreduce(&totalMass_local, &totalMass, 1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);
+  MPI_Allreduce(&totalMZ_local, &totalMZ, 1, MPI_DOUBLE, MPI_SUM, MPI_COMM_WORLD);  
+ #else
   totalMass = totalMass_local;
   totalMZ = totalMZ_local;
-  totalMassOfUncons = massOfUncons_local;
-#endif  
+ #endif  
 
   double zsys;
   zsys = totalMZ / totalMass;
@@ -557,17 +628,6 @@ template<typename T> void ZConstraint<T>::zeroOutVel()
   double COMvel[3];
   double vel[3];
 
-  double tempMass = 0;
-  double tempMVz =0;
-  double tempVz = 0;
-  for(int i = 0; i < nMols; i++){
-    molecules[i].getCOMvel(COMvel);
-    tempMass +=molecules[i].getTotalMass();  
- 	 tempMVz += molecules[i].getTotalMass() * COMvel[whichDirection];
-	 tempVz += COMvel[whichDirection];
-  }
-  cout << "initial velocity of center of mass is " << tempMVz / tempMass << endl;
-
   //zero out the velocities of center of mass of fixed z-constrained molecules
   
   for(int i = 0; i < zconsMols.size(); i++){
@@ -575,7 +635,7 @@ template<typename T> void ZConstraint<T>::zeroOutVel()
     if (states[i] == zcsFixed){	
 
 	   zconsMols[i]->getCOMvel(COMvel);      
-		cout << "before resetting " << indexOfZConsMols[i] <<"'s vz is " << COMvel[whichDirection] << endl;
+		//cout << "before resetting " << indexOfZConsMols[i] <<"'s vz is " << COMvel[whichDirection] << endl;
 
       fixedZAtoms = zconsMols[i]->getMyAtoms(); 
 	  
@@ -586,12 +646,20 @@ template<typename T> void ZConstraint<T>::zeroOutVel()
       }
 
 		zconsMols[i]->getCOMvel(COMvel);
-		cout << "after resetting " << indexOfZConsMols[i] <<"'s vz is " << COMvel[whichDirection] << endl;
+		//cout << "after resetting " << indexOfZConsMols[i] <<"'s vz is " << COMvel[whichDirection] << endl;
     }
 	
   }
 
-  	cout << "before resetting the COMVel of unconstraint molecules is " << calcCOMVel() <<endl;	
+  	//cout << "before resetting the COMVel of moving molecules is " << calcMovingMolsCOMVel() <<endl;	
+
+#ifdef IS_MPI
+  if (worldRank == 0){
+#endif
+    cout << "before resetting the COMVel of sytem is " << calcSysCOMVel() << endl;	
+#ifdef IS_MPI
+  }
+#endif
 		   
   // calculate the vz of center of mass of unconstrained molecules and moving z-constrained molecules
   double MVzOfMovingMols_local;
@@ -657,7 +725,13 @@ template<typename T> void ZConstraint<T>::zeroOutVel()
 
  }
 
-	cout << "after resetting the COMVel of unconstraint molecules is " << calcCOMVel() <<endl;
+#ifdef IS_MPI
+  if (worldRank == 0){
+#endif
+	cout << "after resetting the COMVel of moving molecules is " << calcSysCOMVel() <<endl;
+#ifdef IS_MPI
+  }
+#endif
 
 }
 
@@ -670,16 +744,23 @@ template<typename T> void ZConstraint<T>::doZconstrain
   double COM[3];
   double force[3];
 
-  int nMovingZMols_local;
-  int nMovingZMols;
 
+
   //constrain the molecules which do not reach the specified positions	
     
   //Zero Out the force of z-contrained molecules    
   totalFZ_local = 0;
 
   //calculate the total z-contrained force of fixed z-contrained molecules
-  cout << "Fixed Molecules" << endl;
+
+#ifdef IS_MPI
+  if (worldRank == 0){
+#endif
+    cout << "Fixed Molecules" << endl;
+#ifdef IS_MPI
+  }
+#endif
+
   for(int i = 0; i < zconsMols.size(); i++){
 		
     if (states[i] == zcsFixed){
@@ -694,107 +775,151 @@ template<typename T> void ZConstraint<T>::doZconstrain
       }	
       totalFZ_local += fz[i];
 
-      cout << "index: " << indexOfZConsMols[i] <<"\tcurrent zpos: " << COM[whichDirection] << endl;
+      cout << "index: " << indexOfZConsMols[i] 
+				<<"\tcurrent zpos: " << COM[whichDirection] 
+				<< "\tcurrent fz: " <<fz[i] << endl;
 
     }
 	  
   } 
 
+  //calculate total z-constraint force
+#ifdef IS_MPI
+  MPI_Allreduce(&totalFZ_local, &totalFZ, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
+#else
+  totalFZ = totalFZ_local;
+#endif
+
+	
+  // apply negative to fixed z-constrained molecues;
+  force[0]= 0;
+  force[1]= 0;
+  force[2]= 0;
+
+  for(int i = 0; i < zconsMols.size(); i++){
+
+    if (states[i] == zcsFixed){  
+	
+      int nAtomOfCurZConsMol = zconsMols[i]->getNAtoms();
+      zconsAtoms = zconsMols[i]->getMyAtoms();  
+    
+      for(int j =0; j < nAtomOfCurZConsMol; j++) {
+		  force[whichDirection] = -fz[i]/ nAtomOfCurZConsMol;
+        //force[whichDirection] = - forcePolicy->getZFOfFixedZMols(zconsMols[i], zconsAtoms[j], fz[i]);
+        zconsAtoms[j]->addFrc(force);
+      }
+		
+    }
+	
+  } 
+
+  //cout << "after zero out z-constraint force on fixed z-constraint molecuels "
+  //		   << "total force is " << calcTotalForce() << endl;
+
   //calculate the number of atoms of moving z-constrained molecules
-  nMovingZMols_local = 0;
+  int nMovingZAtoms_local;
+  int nMovingZAtoms;
+	
+  nMovingZAtoms_local = 0;
   for(int i = 0; i < zconsMols.size(); i++)
     if(states[i] == zcsMoving)
-	   nMovingZMols_local += massOfZConsMols[i];
+	   nMovingZAtoms_local += zconsMols[i]->getNAtoms();
   
 #ifdef IS_MPI
-  MPI_Allreduce(&totalFZ_local, &totalFZ, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
-  MPI_Allreduce(&nMovingZMols_local, &nMovingZMols, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
+  MPI_Allreduce(&nMovingZAtoms_local, &nMovingZAtoms, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
 #else
-  totalFZ = totalFZ_local;
-  nMovingZMols = nMovingZMols_local;
+  nMovingZAtoms = nMovingZAtoms_local;
 #endif
 
   force[0]= 0;
   force[1]= 0;
   force[2]= 0;
-  force[whichDirection] = totalFZ / (totNumOfUnconsAtoms + nMovingZMols);
 
   //modify the forces of unconstrained molecules
   for(int i = 0; i < unconsMols.size(); i++){
      
      Atom** unconsAtoms = unconsMols[i]->getMyAtoms();
      
-     for(int j = 0; j < unconsMols[i]->getNAtoms(); j++)          
+     for(int j = 0; j < unconsMols[i]->getNAtoms(); j++){          
+       force[whichDirection] = totalFZ / (totNumOfUnconsAtoms + nMovingZAtoms);
+       //force[whichDirection] = forcePolicy->getZFOfMovingMols(unconsAtoms[j],totalFZ);
        unconsAtoms[j]->addFrc(force);
+     }
      
   }      
 
  //modify the forces of moving z-constrained molecules
   for(int i = 0; i < zconsMols.size(); i++) {
-   if (states[i] == zcsMoving){
+    if (states[i] == zcsMoving){
 	 	
-     Atom** movingZAtoms = zconsMols[i]->getMyAtoms();     
+      Atom** movingZAtoms = zconsMols[i]->getMyAtoms();     
 
-     for(int j = 0; j < zconsMols[i]->getNAtoms(); j++)          
-       movingZAtoms[j]->addFrc(force);
-     }
+      for(int j = 0; j < zconsMols[i]->getNAtoms(); j++){
+        force[whichDirection] = totalFZ / (totNumOfUnconsAtoms + nMovingZAtoms);
+        //force[whichDirection] = forcePolicy->getZFOfMovingMols(movingZAtoms[j],totalFZ);
+        movingZAtoms[j]->addFrc(force);
+      }
+    }
   }
 
-  // apply negative to fixed z-constrained molecues;
-  force[0]= 0;
-  force[1]= 0;
-  force[2]= 0;
+  //cout << "after substracting z-constraint force from moving molecuels "
+  //		  << "total force is " << calcTotalForce()  << endl;
 
-  for(int i = 0; i < zconsMols.size(); i++){
-
-    if (states[i] == zcsFixed){  
-	
-      int nAtomOfCurZConsMol = zconsMols[i]->getNAtoms();
-      zconsAtoms = zconsMols[i]->getMyAtoms();  
-    
-      for(int j =0; j < nAtomOfCurZConsMol; j++) {
-        force[whichDirection] = -fz[i]/ nAtomOfCurZConsMol;
-        zconsAtoms[j]->addFrc(force);
-      }
-		
-    }
-	
-  } 
-
 }
 
 template<typename T> bool ZConstraint<T>::checkZConsState(){
   double COM[3];
   double diff;
   
-  bool changed;
+  int changed_local;
+  int changed;
+	
+  changed_local = 0;
   
-  changed = false;
-  
   for(int i =0; i < zconsMols.size(); i++){
 
     zconsMols[i]->getCOM(COM);
     diff = fabs(COM[whichDirection] - zPos[i]);  
     if (  diff <= zconsTol && states[i] == zcsMoving){
       states[i] = zcsFixed;
-	changed = true;
+	   changed_local = 1;
     }
     else if ( diff > zconsTol && states[i] == zcsFixed){
       states[i] = zcsMoving;
-	changed = true;	  
+	   changed_local = 1;	  
     }
   
   }
 
-  return changed;
+#ifndef IS_MPI
+  changed =changed_local; 
+#else
+  MPI_Allreduce(&changed_local, &changed, 1, MPI_INT,MPI_SUM, MPI_COMM_WORLD);
+#endif
+
+  return changed > 0 ? true : false;
 }
 
 template<typename T> bool ZConstraint<T>::haveFixedZMols(){
+
+  int havingFixed_local;
+  int havingFixed;
+
+  havingFixed_local = 0;
+
   for(int i = 0; i < zconsMols.size(); i++)
-    if (states[i] == zcsFixed)
-      return true;
+    if (states[i] == zcsFixed){
+      havingFixed_local = 1;
+		break;
+    }
 
-  return false;
+#ifndef IS_MPI
+  havingFixed = havingFixed_local;
+#else
+  MPI_Allreduce(&havingFixed_local, &havingFixed, 1, MPI_INT,MPI_SUM, MPI_COMM_WORLD);
+#endif
+
+  return havingFixed > 0 ? true : false;
 }
 
 
@@ -802,11 +927,25 @@ template<typename T> bool ZConstraint<T>::haveMovingZM
  *
  */
 template<typename T> bool ZConstraint<T>::haveMovingZMols(){
+
+  int havingMoving_local;
+  int havingMoving;
+
+  havingMoving_local = 0;
+
   for(int i = 0; i < zconsMols.size(); i++)
-    if (states[i] == zcsMoving)
-      return true;
+    if (states[i] == zcsMoving){
+      havingMoving_local = 1;
+		break;
+    }
 
-  return false;
+#ifndef IS_MPI
+  havingMoving = havingMoving_local;
+#else
+  MPI_Allreduce(&havingMoving_local, &havingMoving, 1, MPI_INT,MPI_SUM, MPI_COMM_WORLD);
+#endif
+
+  return havingMoving > 0 ? true : false;
   
 }
 
@@ -821,15 +960,24 @@ template<typename T> void ZConstraint<T>::doHarmonic()
   double harmonicF;
   double COM[3];
   double diff;
+  double totalFZ_local;
   double totalFZ;
 	
   force[0] = 0;
   force[1] = 0;
   force[2] = 0;
 
-  totalFZ = 0;
+  totalFZ_local = 0;
 
-  cout << "Moving Molecules" << endl;	
+#ifdef IS_MPI
+  if (worldRank == 0){
+#endif
+    cout << "Moving Molecules" << endl;	
+#ifdef IS_MPI
+  }
+#endif
+
+
   for(int i = 0; i < zconsMols.size(); i++) {
 
     if (states[i] == zcsMoving){
@@ -841,35 +989,47 @@ template<typename T> void ZConstraint<T>::doHarmonic()
       harmonicU = 0.5 * kz[i] * diff * diff;  
 		info->lrPot += harmonicU;
 
-      harmonicF =  - kz[i] * diff / zconsMols[i]->getNAtoms();
-		force[whichDirection] = harmonicF;
-      totalFZ += harmonicF;
+      harmonicF =  - kz[i] * diff;
+      totalFZ_local += harmonicF;
+
+       //adjust force
 		
       Atom** movingZAtoms = zconsMols[i]->getMyAtoms();     
 
-       for(int j = 0; j < zconsMols[i]->getNAtoms(); j++)          
+       for(int j = 0; j < zconsMols[i]->getNAtoms(); j++){          
+   		  force[whichDirection] = harmonicF / zconsMols[i]->getNAtoms();
+         //force[whichDirection] = forcePolicy->getHFOfFixedZMols(zconsMols[i], movingZAtoms[j], harmonicF);
          movingZAtoms[j]->addFrc(force);
+       }
     }
 
   }
 
+#ifndef IS_MPI
+  totalFZ = totalFZ_local;
+#else
+  MPI_Allreduce(&totalFZ_local, &totalFZ, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);  
+#endif
+
   force[0]= 0;
   force[1]= 0;
   force[2]= 0;
-  force[whichDirection] = -totalFZ /totNumOfUnconsAtoms;
 
   //modify the forces of unconstrained molecules
   for(int i = 0; i < unconsMols.size(); i++){
      
      Atom** unconsAtoms = unconsMols[i]->getMyAtoms();
      
-     for(int j = 0; j < unconsMols[i]->getNAtoms(); j++)          
+     for(int j = 0; j < unconsMols[i]->getNAtoms(); j++){          
+       force[whichDirection] = - totalFZ /totNumOfUnconsAtoms;
+       //force[whichDirection] = - forcePolicy->getHFOfUnconsMols(unconsAtoms[j], totalFZ);
        unconsAtoms[j]->addFrc(force);     
+     }
   }   
 
 }
 
-template<typename T> double ZConstraint<T>::calcCOMVel()
+template<typename T> double ZConstraint<T>::calcMovingMolsCOMVel()
 {
   double MVzOfMovingMols_local;
   double MVzOfMovingMols;
@@ -910,23 +1070,134 @@ template<typename T> double ZConstraint<T>::calcCOMVel
 }
 
 
-template<typename T> double ZConstraint<T>::calcCOMVel2()
+template<typename T> double ZConstraint<T>::calcSysCOMVel()
 {
   double COMvel[3];
-  double tempMVz = 0;
-  int index;
-		
+  double tempMVz_local;
+  double tempMVz;
+  double massOfZCons_local;
+  double massOfZCons;
+
+
+ tempMVz_local = 0;
+
   for(int i =0 ; i < nMols; i++){
-	 index = isZConstraintMol(&molecules[i]);
-    if( index == -1){
-       molecules[i].getCOMvel(COMvel);
-	    tempMVz += molecules[i].getTotalMass()*COMvel[whichDirection];
-    }
-	 else if(states[i] == zcsMoving){
-       zconsMols[index]->getCOMvel(COMvel);
-	    tempMVz += massOfZConsMols[index]*COMvel[whichDirection];    
-	 }
+    molecules[i].getCOMvel(COMvel);
+	 tempMVz_local += molecules[i].getTotalMass()*COMvel[whichDirection];
   }
+
+  massOfZCons_local = 0;
 	
-  return tempMVz /totalMassOfUncons;
+  for(int i = 0; i < massOfZConsMols.size(); i++){
+    massOfZCons_local += massOfZConsMols[i];
+  }
+#ifndef IS_MPI
+  massOfZCons = massOfZCons_local;
+  tempMVz = tempMVz_local;
+#else
+  MPI_Allreduce(&massOfZCons_local, &massOfZCons, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
+  MPI_Allreduce(&tempMVz_local, &tempMVz, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
+#endif
+
+  return tempMVz /(totalMassOfUncons + massOfZCons);
 }
+
+template<typename T> double ZConstraint<T>::calcTotalForce(){
+
+  double force[3];  
+  double totalForce_local;
+  double totalForce;
+
+  totalForce_local = 0;
+
+  for(int i = 0; i < nAtoms; i++){
+    atoms[i]->getFrc(force);
+    totalForce_local += force[whichDirection];
+  }
+
+#ifndef IS_MPI
+  totalForce = totalForce_local;
+#else
+  MPI_Allreduce(&totalForce_local, &totalForce, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
+#endif
+
+  return totalForce;
+
+}
+
+/**
+ *
+ */
+
+template<typename T> void ZConstraint<T>::PolicyByNumber::update(){
+  //calculate the number of atoms of moving z-constrained molecules
+  int nMovingZAtoms_local;
+  int nMovingZAtoms;
+	
+  nMovingZAtoms_local = 0;
+  for(int i = 0; i < (zconsIntegrator->zconsMols).size(); i++)
+    if((zconsIntegrator->states)[i] == (zconsIntegrator->zcsMoving))
+	   nMovingZAtoms_local += (zconsIntegrator->zconsMols)[i]->getNAtoms();
+  
+#ifdef IS_MPI
+  MPI_Allreduce(&nMovingZAtoms_local, &nMovingZAtoms, 1, MPI_INT, MPI_SUM, MPI_COMM_WORLD);
+#else
+  nMovingZAtoms = nMovingZAtoms_local;
+#endif
+  totNumOfMovingAtoms = nMovingZAtoms + zconsIntegrator->totNumOfUnconsAtoms;
+}
+
+template<typename T> double ZConstraint<T>::PolicyByNumber::getZFOfFixedZMols(Molecule* mol, Atom* atom, double totalForce){
+  return totalForce / mol->getNAtoms();
+}
+
+template<typename T> double ZConstraint<T>::PolicyByNumber::getZFOfMovingMols(Atom* atom, double totalForce){
+  return totalForce / totNumOfMovingAtoms;
+}
+
+template<typename T> double ZConstraint<T>::PolicyByNumber::getHFOfFixedZMols(Molecule* mol, Atom* atom, double totalForce){
+    return totalForce / mol->getNAtoms();
+}
+
+template<typename T> double ZConstraint<T>::PolicyByNumber::getHFOfUnconsMols(Atom* atom, double totalForce){
+  return totalForce / zconsIntegrator->totNumOfUnconsAtoms;
+}
+
+/**
+ *
+ */
+
+template<typename T> void ZConstraint<T>::PolicyByMass::update(){
+  //calculate the number of atoms of moving z-constrained molecules
+  double massOfMovingZAtoms_local;
+  double massOfMovingZAtoms;
+	
+  massOfMovingZAtoms_local = 0;
+  for(int i = 0; i < (zconsIntegrator->zconsMols).size(); i++)
+    if((zconsIntegrator->states)[i] == (zconsIntegrator->zcsMoving))
+	   massOfMovingZAtoms_local += (zconsIntegrator->zconsMols)[i]->getTotalMass();
+  
+#ifdef IS_MPI
+  MPI_Allreduce(&massOfMovingZAtoms_local, &massOfMovingZAtoms, 1, MPI_DOUBLE,MPI_SUM, MPI_COMM_WORLD);
+#else
+  massOfMovingZAtoms = massOfMovingZAtoms_local;
+#endif
+  totMassOfMovingAtoms = massOfMovingZAtoms_local + zconsIntegrator->totalMassOfUncons;
+}
+
+template<typename T> double ZConstraint<T>::PolicyByMass::getZFOfFixedZMols(Molecule* mol, Atom* atom, double totalForce){
+  return totalForce * atom->getMass() / mol->getTotalMass();
+}
+
+template<typename T> double ZConstraint<T>::PolicyByMass::getZFOfMovingMols( Atom* atom, double totalForce){
+    return totalForce * atom->getMass() / totMassOfMovingAtoms;
+}
+
+template<typename T> double ZConstraint<T>::PolicyByMass::getHFOfFixedZMols(Molecule* mol, Atom* atom, double totalForce){
+  return totalForce * atom->getMass() / mol->getTotalMass();
+}
+
+template<typename T> double ZConstraint<T>::PolicyByMass::getHFOfUnconsMols(Atom* atom, double totalForce){
+    return totalForce * atom->getMass() / zconsIntegrator->totalMassOfUncons;
+}
+