--- branches/development/src/constraints/Rattle.cpp	2011/11/22 20:38:56	1665
+++ branches/development/src/constraints/Rattle.cpp	2012/05/22 21:55:31	1715
@@ -45,8 +45,12 @@ namespace OpenMD {
 #include "utils/simError.h"
 namespace OpenMD {
 
-  Rattle::Rattle(SimInfo* info) : info_(info), maxConsIteration_(10), consTolerance_(1.0e-6) {
+  Rattle::Rattle(SimInfo* info) : info_(info), maxConsIteration_(10), consTolerance_(1.0e-6), doRattle_(false) {
     
+    if (info_->getNConstraints() > 0)
+      doRattle_ = true;
+    
+
     if (info_->getSimParams()->haveDt()) {
       dt_ = info_->getSimParams()->getDt();
     } else {
@@ -60,17 +64,17 @@ namespace OpenMD {
   }
 
   void Rattle::constraintA() {
-    if (info_->getNConstraints() > 0) {
-      doConstraint(&Rattle::constraintPairA);
-    }
+    if (!doRattle_) return;
+    doConstraint(&Rattle::constraintPairA);
   }
   void Rattle::constraintB() {
-    if (info_->getNConstraints() > 0) {
-      doConstraint(&Rattle::constraintPairB);
-    }
+    if (!doRattle_) return;    
+    doConstraint(&Rattle::constraintPairB);
   }
 
   void Rattle::doConstraint(ConstraintPairFuncPtr func) {
+    if (!doRattle_) return;
+
     Molecule* mol;
     SimInfo::MoleculeIterator mi;
     ConstraintElem* consElem;
@@ -149,6 +153,7 @@ namespace OpenMD {
   }
 
   int Rattle::constraintPairA(ConstraintPair* consPair){
+
     ConstraintElem* consElem1 = consPair->getConsElem1();
     ConstraintElem* consElem2 = consPair->getConsElem2();