--- branches/development/src/nonbonded/LJ.cpp	2011/01/05 14:49:05	1536
+++ branches/development/src/nonbonded/LJ.cpp	2011/06/09 20:26:29	1579
@@ -244,9 +244,8 @@ namespace OpenMD {
     
     if (!initialized_) initialize();
     
-    pair<AtomType*, AtomType*> key = make_pair(idat.atype1, idat.atype2);
     map<pair<AtomType*, AtomType*>, LJInteractionData>::iterator it;
-    it = MixingMap.find(key);
+    it = MixingMap.find( idat.atypes );
     
     if (it != MixingMap.end())  {
       
@@ -262,31 +261,37 @@ namespace OpenMD {
       RealType myDeriv = 0.0;
       RealType myDerivC = 0.0;
      
-      ros = idat.rij * sigmai;
+      ros = *(idat.rij) * sigmai;
+      
+      cerr << "ros = " << ros << "\n";
       
       getLJfunc(ros, myPot, myDeriv);
       
       if (shiftedPot_) {
-        rcos = idat.rcut * sigmai;
+        rcos = *(idat.rcut) * sigmai;
         getLJfunc(rcos, myPotC, myDerivC);
         myDerivC = 0.0;
       } else if (LJ::shiftedFrc_) {
-        rcos = idat.rcut * sigmai;
+        rcos = *(idat.rcut) * sigmai;
         getLJfunc(rcos, myPotC, myDerivC);
-        myPotC = myPotC + myDerivC * (idat.rij - idat.rcut) * sigmai;
+        myPotC = myPotC + myDerivC * (*(idat.rij) - *(idat.rcut)) * sigmai;
       } else {
         myPotC = 0.0;
         myDerivC = 0.0;        
       }
 
-      RealType pot_temp = idat.vdwMult * epsilon * (myPot - myPotC);
-      idat.vpair[0] += pot_temp;
-      
-      RealType dudr = idat.sw * idat.vdwMult * epsilon * (myDeriv - 
-                                                          myDerivC)*sigmai;
+      cerr << "myPot =  " << myPot << "\n";
+      cerr << "myPotC =  " << myPotC << "\n";
+      cerr << "epsilon =  " << epsilon << "\n";
+      cerr << "vdwm =  " << *(idat.vdwMult) << "\n";
+      RealType pot_temp = *(idat.vdwMult) * epsilon * (myPot - myPotC);
+      *(idat.vpair) += pot_temp;
       
-      idat.pot[0] += idat.sw * pot_temp;
-      idat.f1 = idat.d * dudr / idat.rij;      
+      RealType dudr = *(idat.sw) * *(idat.vdwMult) * epsilon * (myDeriv - 
+                                                             myDerivC)*sigmai;
+      
+      (idat.pot)[VANDERWAALS_FAMILY] += *(idat.sw) * pot_temp;
+      *(idat.f1) = *(idat.d) * dudr / *(idat.rij);
     }
     return;
   }
@@ -306,11 +311,10 @@ namespace OpenMD {
     return;
   }
   
-  RealType LJ::getSuggestedCutoffRadius(AtomType* at1, AtomType* at2) {
+  RealType LJ::getSuggestedCutoffRadius(pair<AtomType*, AtomType*> atypes) {
     if (!initialized_) initialize();   
-    pair<AtomType*, AtomType*> key = make_pair(at1, at2); 
     map<pair<AtomType*, AtomType*>, LJInteractionData>::iterator it;
-    it = MixingMap.find(key);
+    it = MixingMap.find(atypes);
     if (it == MixingMap.end()) 
       return 0.0;
     else  {