--- trunk/OOPSE/libmdtools/Molecule.cpp	2003/04/03 20:57:56	449
+++ trunk/OOPSE/libmdtools/Molecule.cpp	2003/04/11 15:16:59	490
@@ -164,5 +164,34 @@ void Molecule::getCOM( double COM[3] ) {
   COM[1] /= mtot;
   COM[2] /= mtot;
  
-  return COM;
 }
+
+double Molecule::getCOMvel( double COMvel[3] ) {
+
+  double mass, mtot;
+  int i;
+
+  COMvel[0] = 0.0;
+  COMvel[1] = 0.0;
+  COMvel[2] = 0.0;
+  mtot   = 0.0;
+
+  for (i=0; i < nAtoms; i++) {
+    if (myAtoms[i] != NULL) {
+
+      mass = myAtoms[i]->getMass();
+      mtot   += mass;
+      COMvel[0] += myAtoms[i]->get_vx() * mass;
+      COMvel[1] += myAtoms[i]->get_vy() * mass;
+      COMvel[2] += myAtoms[i]->get_vz() * mass;
+
+    }
+  }
+
+  COMvel[0] /= mtot;
+  COMvel[1] /= mtot;
+  COMvel[2] /= mtot;
+ 
+  return mtot;
+
+}