--- trunk/src/io/DumpWriter.cpp	2010/05/10 17:28:26	1442
+++ branches/development/src/io/DumpWriter.cpp	2011/09/14 21:15:17	1629
@@ -60,6 +60,7 @@ namespace OpenMD {
     Globals* simParams = info->getSimParams();
     needCompression_ = simParams->getCompressDumpFile();
     needForceVector_ = simParams->getOutputForceVector();
+    needParticlePot_ = simParams->getOutputParticlePotential();
     createDumpFile_ = true;
 #ifdef HAVE_LIBZ
     if (needCompression_) {
@@ -138,6 +139,7 @@ namespace OpenMD {
     
     needCompression_ = simParams->getCompressDumpFile();
     needForceVector_ = simParams->getOutputForceVector();
+    needParticlePot_ = simParams->getOutputParticlePotential();
     
 #ifdef HAVE_LIBZ
     if (needCompression_) {
@@ -306,7 +308,8 @@ namespace OpenMD {
     }
     
     const int masterNode = 0;
-
+    int nProc;
+    MPI_Comm_size(MPI_COMM_WORLD, &nProc);
     if (worldRank == masterNode) {	
       os << "  <Snapshot>\n";	
       writeFrameProperties(os, info_->getSnapshotManager()->getCurrentSnapshot());
@@ -314,13 +317,12 @@ namespace OpenMD {
 	
       os << buffer;
 
-      int nProc;
-      MPI_Comm_size(MPI_COMM_WORLD, &nProc);
       for (int i = 1; i < nProc; ++i) {
 
         // receive the length of the string buffer that was
         // prepared by processor i
 
+        MPI_Bcast(&i, 1, MPI_INT,masterNode,MPI_COMM_WORLD);
         int recvLength;
         MPI_Recv(&recvLength, 1, MPI_INT, i, 0, MPI_COMM_WORLD, &istatus);
         char* recvBuffer = new char[recvLength];
@@ -337,8 +339,14 @@ namespace OpenMD {
       os.flush();
     } else {
       int sendBufferLength = buffer.size() + 1;
-      MPI_Send(&sendBufferLength, 1, MPI_INT, masterNode, 0, MPI_COMM_WORLD);
-      MPI_Send((void *)buffer.c_str(), sendBufferLength, MPI_CHAR, masterNode, 0, MPI_COMM_WORLD);
+      int myturn = 0;
+      for (int i = 1; i < nProc; ++i){
+        MPI_Bcast(&myturn,1, MPI_INT,masterNode,MPI_COMM_WORLD);
+        if (myturn == worldRank){
+          MPI_Send(&sendBufferLength, 1, MPI_INT, masterNode, 0, MPI_COMM_WORLD);
+          MPI_Send((void *)buffer.c_str(), sendBufferLength, MPI_CHAR, masterNode, 0, MPI_COMM_WORLD);
+        }
+      }
     }
 
 #endif // is_mpi
@@ -458,6 +466,22 @@ namespace OpenMD {
         line += tempBuffer;
       }      
     }
+    if (needParticlePot_) {
+      type += "u";
+      RealType particlePot;
+
+      particlePot = integrableObject->getParticlePot();
+
+      if (isinf(particlePot) || isnan(particlePot)) {      
+        sprintf( painCave.errMsg,
+                 "DumpWriter detected a numerical error writing the particle "
+                 " potential for object %d", index);      
+        painCave.isFatal = 1;
+        simError();
+      }
+      sprintf(tempBuffer, " %13e", particlePot);
+      line += tempBuffer;
+    }
     
     sprintf(tempBuffer, "%10d %7s %s\n", index, type.c_str(), line.c_str());
     return std::string(tempBuffer);