--- branches/development/src/nonbonded/GB.cpp	2010/10/03 22:18:59	1505
+++ branches/development/src/nonbonded/GB.cpp	2011/01/05 14:49:05	1536
@@ -263,7 +263,7 @@ namespace OpenMD {
     }      
   }
    
-  void GB::calcForce(InteractionData idat) {
+  void GB::calcForce(InteractionData &idat) {
 
     if (!initialized_) initialize();
     
@@ -357,11 +357,11 @@ namespace OpenMD {
     Vector3d rxu2 = cross(idat.d, ul2);
     Vector3d uxu = cross(ul1, ul2);
     
-    idat.pot += U*idat.sw;
+    idat.pot[0] += U*idat.sw;
     idat.f1 += dUdr * rhat + dUda * ul1 + dUdb * ul2;    
     idat.t1 += dUda * rxu1 - dUdg * uxu;
     idat.t2 += dUdb * rxu2 - dUdg * uxu;
-    idat.vpair += U*idat.sw;
+    idat.vpair[0] += U*idat.sw;
 
     return;