--- trunk/OOPSE/libmdtools/calc_LJ_FF.F90	2003/03/21 17:42:12	378
+++ trunk/OOPSE/libmdtools/calc_LJ_FF.F90	2003/04/11 15:16:59	490
@@ -2,12 +2,13 @@
 !! Corresponds to the force field defined in lj_FF.cpp 
 !! @author Charles F. Vardeman II
 !! @author Matthew Meineke
-!! @version $Id: calc_LJ_FF.F90,v 1.1.1.1 2003-03-21 17:42:12 mmeineke Exp $, $Date: 2003-03-21 17:42:12 $, $Name: not supported by cvs2svn $, $Revision: 1.1.1.1 $
+!! @version $Id: calc_LJ_FF.F90,v 1.5 2003-04-11 15:16:59 gezelter Exp $, $Date: 2003-04-11 15:16:59 $, $Name: not supported by cvs2svn $, $Revision: 1.5 $
 
 module lj
   use definitions
   use atype_module
   use vector_class
+  use simulation
 #ifdef IS_MPI
   use mpiSimulation
 #endif
@@ -180,7 +181,7 @@ contains
     integer, intent(in) ::  atom1, atom2
     real( kind = dp ), intent(in) :: rij, r2
     real( kind = dp ) :: pot
-    real( kind = dp ), dimension(:,:) :: f    
+    real( kind = dp ), dimension(3,getNlocal()) :: f    
     real( kind = dp ), intent(in), dimension(3) :: d
     logical, intent(in) :: do_pot, do_stress
 
@@ -194,6 +195,7 @@ contains
     real( kind = dp ) :: t6
     real( kind = dp ) :: t12
     real( kind = dp ) :: delta
+    integer :: id1, id2
 
 
     if (rij.lt.LJ_rcut)  then
@@ -218,9 +220,9 @@ contains
        
        dudr = 24.0E0_DP * epsilon * (t6 - 2.0E0_DP*t12) / rij
        
-       drdx = -d(1) / rij
-       drdy = -d(2) / rij
-       drdz = -d(3) / rij
+       drdx = d(1) / rij
+       drdy = d(2) / rij
+       drdz = d(3) / rij
        
        fx = dudr * drdx
        fy = dudr * drdy
@@ -253,16 +255,31 @@ contains
 #endif
        
        if (do_stress) then
-          tau_Temp(1) = tau_Temp(1) + fx * d(1)
-          tau_Temp(2) = tau_Temp(2) + fx * d(2)
-          tau_Temp(3) = tau_Temp(3) + fx * d(3)
-          tau_Temp(4) = tau_Temp(4) + fy * d(1)
-          tau_Temp(5) = tau_Temp(5) + fy * d(2)
-          tau_Temp(6) = tau_Temp(6) + fy * d(3)
-          tau_Temp(7) = tau_Temp(7) + fz * d(1)
-          tau_Temp(8) = tau_Temp(8) + fz * d(2)
-          tau_Temp(9) = tau_Temp(9) + fz * d(3)
-          virial_Temp = virial_Temp + (tau_Temp(1) + tau_Temp(5) + tau_Temp(9))
+
+#ifdef IS_MPI
+          id1 = tagRow(atom1)
+          id2 = tagColumn(atom2)
+#else
+          id1 = atom1
+          id2 = atom2
+#endif
+
+          if (molMembershipList(id1) .ne. molMembershipList(id2)) then
+             tau_Temp(1) = tau_Temp(1) + fx * d(1)
+             tau_Temp(2) = tau_Temp(2) + fx * d(2)
+             tau_Temp(3) = tau_Temp(3) + fx * d(3)
+             tau_Temp(4) = tau_Temp(4) + fy * d(1)
+             tau_Temp(5) = tau_Temp(5) + fy * d(2)
+             tau_Temp(6) = tau_Temp(6) + fy * d(3)
+             tau_Temp(7) = tau_Temp(7) + fz * d(1)
+             tau_Temp(8) = tau_Temp(8) + fz * d(2)
+             tau_Temp(9) = tau_Temp(9) + fz * d(3)
+             virial_Temp = virial_Temp + &
+                  (tau_Temp(1) + tau_Temp(5) + tau_Temp(9))
+          else
+             write(0,*) 'skipping ', id1, id2, molMembershipList(id1), molMembershipList(id2)
+          endif
+
        endif
        
     endif