--- trunk/OOPSE/libmdtools/do_Forces.F90	2003/03/31 22:09:39	439
+++ trunk/OOPSE/libmdtools/do_Forces.F90	2003/04/01 16:50:14	441
@@ -4,7 +4,7 @@
 
 !! @author Charles F. Vardeman II
 !! @author Matthew Meineke
-!! @version $Id: do_Forces.F90,v 1.6 2003-03-31 22:09:39 chuckv Exp $, $Date: 2003-03-31 22:09:39 $, $Name: not supported by cvs2svn $, $Revision: 1.6 $
+!! @version $Id: do_Forces.F90,v 1.7 2003-04-01 16:50:14 chuckv Exp $, $Date: 2003-04-01 16:50:14 $, $Name: not supported by cvs2svn $, $Revision: 1.7 $
 
 module do_Forces
   use force_globals
@@ -168,7 +168,7 @@ contains
     logical :: do_pot
     logical :: do_stress
 #ifdef IS_MPI 
-    real( kind = DP ) :: pot_local = 0.0_dp
+    real( kind = DP ) :: pot_local
     integer :: nrow
     integer :: ncol
 #endif
@@ -189,6 +189,7 @@ contains
     !! initialize local variables  
 
 #ifdef IS_MPI
+    pot_local = 0.0_dp
     nlocal = getNlocal()
     nrow   = getNrow(plan_row)
     ncol   = getNcol(plan_col)
@@ -196,7 +197,7 @@ contains
     nlocal = getNlocal()
     natoms = nlocal
 #endif
-
+   
     call getRcut(rcut,rc2=rcutsq)
     call getRlist(rlist,rlistsq)
     
@@ -277,7 +278,7 @@ contains
                                 
                 if (rijsq <  rcutsq) then
                    call do_pair(i, j, rijsq, d, do_pot, do_stress, &
-                        u_l, A, f, t,pot)
+                        u_l, A, f, t, pot_local)
                 endif
              endif
           enddo inner
@@ -299,7 +300,7 @@ contains
 
                 call get_interatomic_vector(q_Row(:,i), q_Col(:,j), d, rijsq)
                 call do_pair(i, j, rijsq, d, do_pot, do_stress, &
-                     u_l, A, f, t,pot)
+                     u_l, A, f, t, pot_local)
 
              enddo
           endif
@@ -346,7 +347,7 @@ contains
                 
                 if (rijsq <  rcutsq) then
                    call do_pair(i, j, rijsq, d, do_pot, do_stress, &
-                        u_l, A, f, t,pot)
+                        u_l, A, f, t, pot)
                 endif
              endif
           enddo inner
@@ -368,7 +369,7 @@ contains
 
                 call get_interatomic_vector(q(:,i), q(:,j), d, rijsq)
                 call do_pair(i, j, rijsq, d, do_pot, do_stress, &
-                     u_l, A, f, t,pot)
+                     u_l, A, f, t, pot)
 
              enddo
           endif
@@ -472,7 +473,7 @@ contains
 #ifdef IS_MPI
 
     if (do_pot) then
-       pot = pot_local
+       pot = pot + pot_local
        !! we assume the c code will do the allreduce to get the total potential
        !! we could do it right here if we needed to...
     endif
@@ -495,7 +496,7 @@ contains
     
   end subroutine do_force_loop
 
-  subroutine do_pair(i, j, rijsq, d, do_pot, do_stress, u_l, A, f, t,pot)
+  subroutine do_pair(i, j, rijsq, d, do_pot, do_stress, u_l, A, f, t, pot)
 
     real( kind = dp ) :: pot
     real( kind = dp ), dimension(:,:) :: u_l
@@ -698,7 +699,7 @@ contains
 #else
     unique_id_2 = atom2
 #endif
-    
+
 #ifdef IS_MPI
     !! this situation should only arise in MPI simulations
     if (unique_id_1 == unique_id_2) then
@@ -708,14 +709,18 @@ contains
     
     !! this prevents us from doing the pair on multiple processors
     if (unique_id_1 < unique_id_2) then
-       if (mod(unique_id_1 + unique_id_2,2) == 0) skip_it = .true.
-       return
+       if (mod(unique_id_1 + unique_id_2,2) == 0) then
+          skip_it = .true.
+          return
+       endif
     else                
-       if (mod(unique_id_1 + unique_id_2,2) == 1) skip_it = .true.
-       return
+       if (mod(unique_id_1 + unique_id_2,2) == 1) then 
+          skip_it = .true.
+          return
+       endif
     endif
 #endif
-
+ 
     !! the rest of these situations can happen in all simulations:
     do i = 1, nExcludes_global       
        if ((excludesGlobal(i) == unique_id_1) .or. &
@@ -724,7 +729,7 @@ contains
           return
        endif
     enddo
- 
+
     do i = 1, nExcludes_local
        if (excludesLocal(1,i) == unique_id_1) then
           if (excludesLocal(2,i) == unique_id_2) then