--- trunk/OOPSE/libmdtools/calc_reaction_field.F90	2003/04/09 04:06:43	483
+++ trunk/OOPSE/libmdtools/calc_reaction_field.F90	2003/07/16 21:30:56	626
@@ -9,34 +9,53 @@ module reaction_field
 #endif
   implicit none
 
-  real(kind=dp), save :: rrf
+  PRIVATE
+  
+  real(kind=dp), save :: rrf = 1.0_dp
   real(kind=dp), save :: rt
-  real(kind=dp), save :: dielect
-  real(kind=dp), save :: rrfsq
+  real(kind=dp), save :: dielect = 1.0_dp
+  real(kind=dp), save :: rrfsq = 1.0_dp
   real(kind=dp), save :: pre
-  logical, save :: rf_initialized = .false.
+  logical, save :: rf_initialized = .false., haveCuts = .false.
+  logical, save :: haveDie = .false.
 
+  PUBLIC::initialize_rf
+  PUBLIC::setCutoffsRF
+  PUBLIC::accumulate_rf
+  PUBLIC::accumulate_self_rf
+  PUBLIC::reaction_field_final
+  PUBLIC::rf_correct_forces
+
 contains
   
-  subroutine initialize_rf(this_rrf, this_rt, this_dielect)
-    real(kind=dp), intent(in) :: this_rrf, this_rt, this_dielect
-
-    rrf = this_rrf
-    rt = this_rt
+  subroutine initialize_rf(this_dielect)
+    real(kind=dp), intent(in) :: this_dielect
+    
     dielect = this_dielect
+
+    pre = 14.38362d0*2.0d0*(dielect-1.0d0)/((2.0d0*dielect+1.0d0)*rrfsq*rrf) 
     
+    haveDie = .true.
+    if (haveCuts) rf_initialized = .true.
+
+    return
+  end subroutine initialize_rf
+
+  subroutine setCutoffsRF( this_rrf, this_rt )
+
+    real(kind=dp), intent(in) :: this_rrf, this_rt
+
+    rrf = this_rrf
+    rt  = this_rt
+
     rrfsq = rrf * rrf
     pre = 14.38362d0*2.0d0*(dielect-1.0d0)/((2.0d0*dielect+1.0d0)*rrfsq*rrf)
     
+    haveCuts = .true.
+    if (haveDie) rf_initialized = .true.
 
-    write(*,*) 'rrf = ', rrf
-    write(*,*) 'rt = ', rt
-    write(*,*) 'dielect = ', dielect
-    write(*,*) 'pre = ', pre
-    rf_initialized = .true.
-    
-    return
-  end subroutine initialize_rf
+  end subroutine setCutoffsRF
+
   
   subroutine accumulate_rf(atom1, atom2, rij, u_l)
 
@@ -59,6 +78,7 @@ contains
        if (rij.lt.rt) then
           taper = 1.0d0
        else
+          write(*,*) 'rf in taper region'
           taper = (rrf + 2.0d0*rij - 3.0d0*rt)*(rrf-rij)**2/ ((rrf-rt)**3)
        endif
        
@@ -183,6 +203,7 @@ contains
        if (rij.lt.rt) then
           dtdr = 0.0d0
        else
+          write(*,*) 'rf correct in taper region'
           dtdr = 6.0d0*(rij*rij - rij*rt - rij*rrf +rrf*rt)/((rrf-rt)**3)
        endif
        
@@ -237,15 +258,21 @@ contains
        
        if (do_stress) then          
           if (molMembershipList(atom1) .ne. molMembershipList(atom2)) then
-             tau_Temp(1) = tau_Temp(1) + dudx * d(1)
-             tau_Temp(2) = tau_Temp(2) + dudx * d(2)
-             tau_Temp(3) = tau_Temp(3) + dudx * d(3)
-             tau_Temp(4) = tau_Temp(4) + dudy * d(1)
-             tau_Temp(5) = tau_Temp(5) + dudy * d(2)
-             tau_Temp(6) = tau_Temp(6) + dudy * d(3)
-             tau_Temp(7) = tau_Temp(7) + dudz * d(1)
-             tau_Temp(8) = tau_Temp(8) + dudz * d(2)
-             tau_Temp(9) = tau_Temp(9) + dudz * d(3)
+
+             ! because the d vector is the rj - ri vector, and 
+             ! because dudx, dudy, and dudz are the
+             ! (positive) force on atom i (negative on atom j) we need
+             ! a negative sign here:
+
+             tau_Temp(1) = tau_Temp(1) - d(1) * dudx
+             tau_Temp(2) = tau_Temp(2) - d(1) * dudy
+             tau_Temp(3) = tau_Temp(3) - d(1) * dudz
+             tau_Temp(4) = tau_Temp(4) - d(2) * dudx
+             tau_Temp(5) = tau_Temp(5) - d(2) * dudy
+             tau_Temp(6) = tau_Temp(6) - d(2) * dudz
+             tau_Temp(7) = tau_Temp(7) - d(3) * dudx
+             tau_Temp(8) = tau_Temp(8) - d(3) * dudy
+             tau_Temp(9) = tau_Temp(9) - d(3) * dudz
              virial_Temp = virial_Temp + &
                   (tau_Temp(1) + tau_Temp(5) + tau_Temp(9))
           endif