--- trunk/src/constraints/Rattle.cpp	2014/04/15 20:36:19	1983
+++ trunk/src/constraints/Rattle.cpp	2014/09/26 22:22:28	2022
@@ -52,6 +52,8 @@ namespace OpenMD {
     if (info_->getNGlobalConstraints() > 0)
       doRattle_ = true;
     
+    if (!doRattle_) return;
+
     Globals* simParams = info_->getSimParams();
 
     if (simParams->haveDt()) {
@@ -73,9 +75,10 @@ namespace OpenMD {
     constraintOutputFile_ = getPrefix(info_->getFinalConfigFileName()) + 
       ".constraintForces";
 
+
     // create ConstraintWriter  
     constraintWriter_ = new ConstraintWriter(info_, 
-                                             constraintOutputFile_.c_str());   
+                                             constraintOutputFile_.c_str());
 
     if (!constraintWriter_){
       sprintf(painCave.errMsg, "Failed to create ConstraintWriter\n");
@@ -220,13 +223,14 @@ namespace OpenMD {
     RealType rabsq = consPair->getConsDistSquare();
     RealType diffsq = rabsq - pabsq;
 
+
     // the original rattle code from alan tidesley
     if (fabs(diffsq) > (consTolerance_ * rabsq * 2)){
     
       Vector3d oldPosA = consElem1->getPrevPos();
       Vector3d oldPosB = consElem2->getPrevPos();      
 
-      Vector3d rab = oldPosA - oldPosB;    
+      Vector3d rab = oldPosA - oldPosB;          
 
       currentSnapshot_->wrapVector(rab);