src/UseTheForce/doForces.F90

!!
!! Copyright (c) 2005 The University of Notre Dame. All Rights Reserved.
!!
!! The University of Notre Dame grants you ("Licensee") a
!! non-exclusive, royalty free, license to use, modify and
!! redistribute this software in source and binary code form, provided
!! that the following conditions are met:
!!
!! 1. Acknowledgement of the program authors must be made in any
!!    publication of scientific results based in part on use of the
!!    program.  An acceptable form of acknowledgement is citation of
!!    the article in which the program was described (Matthew
!!    A. Meineke, Charles F. Vardeman II, Teng Lin, Christopher
!!    J. Fennell and J. Daniel Gezelter, "OOPSE: An Object-Oriented
!!    Parallel Simulation Engine for Molecular Dynamics,"
!!    J. Comput. Chem. 26, pp. 252-271 (2005))
!!
!! 2. Redistributions of source code must retain the above copyright
!!    notice, this list of conditions and the following disclaimer.
!!
!! 3. Redistributions in binary form must reproduce the above copyright
!!    notice, this list of conditions and the following disclaimer in the
!!    documentation and/or other materials provided with the
!!    distribution.
!!
!! This software is provided "AS IS," without a warranty of any
!! kind. All express or implied conditions, representations and
!! warranties, including any implied warranty of merchantability,
!! fitness for a particular purpose or non-infringement, are hereby
!! excluded.  The University of Notre Dame and its licensors shall not
!! be liable for any damages suffered by licensee as a result of
!! using, modifying or distributing the software or its
!! derivatives. In no event will the University of Notre Dame or its
!! licensors be liable for any lost revenue, profit or data, or for
!! direct, indirect, special, consequential, incidental or punitive
!! damages, however caused and regardless of the theory of liability,
!! arising out of the use of or inability to use software, even if the
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!!

!! doForces.F90
!! module doForces
!! Calculates Long Range forces.

!! @author Charles F. Vardeman II
!! @author Matthew Meineke
!! @version $Id: doForces.F90,v 1.27 2005-08-09 19:40:56 chuckv Exp $, $Date: 2005-08-09 19:40:56 $, $Name: not supported by cvs2svn $, $Revision: 1.27 $


module doForces
  use force_globals
  use simulation
  use definitions
  use atype_module
  use switcheroo
  use neighborLists  
  use lj
  use sticky
  use electrostatic_module
  use reaction_field
  use gb_pair
  use shapes
  use vector_class
  use eam
  use status
#ifdef IS_MPI
  use mpiSimulation
#endif

  implicit none
  PRIVATE

#define __FORTRAN90
#include "UseTheForce/fSwitchingFunction.h"
#include "UseTheForce/DarkSide/fInteractionMap.h"

  INTEGER, PARAMETER:: PREPAIR_LOOP = 1
  INTEGER, PARAMETER:: PAIR_LOOP    = 2

  logical, save :: haveRlist = .false.
  logical, save :: haveNeighborList = .false.
  logical, save :: haveSIMvariables = .false.
  logical, save :: haveSaneForceField = .false.
  logical, save :: haveInteractionMap = .false.

  logical, save :: FF_uses_DirectionalAtoms
  logical, save :: FF_uses_LennardJones
  logical, save :: FF_uses_Electrostatics
  logical, save :: FF_uses_Charges
  logical, save :: FF_uses_Dipoles
  logical, save :: FF_uses_Quadrupoles
  logical, save :: FF_uses_Sticky
  logical, save :: FF_uses_StickyPower
  logical, save :: FF_uses_GayBerne
  logical, save :: FF_uses_EAM
  logical, save :: FF_uses_Shapes
  logical, save :: FF_uses_FLARB
  logical, save :: FF_uses_RF

  logical, save :: SIM_uses_DirectionalAtoms
  logical, save :: SIM_uses_LennardJones
  logical, save :: SIM_uses_Electrostatics
  logical, save :: SIM_uses_Charges
  logical, save :: SIM_uses_Dipoles
  logical, save :: SIM_uses_Quadrupoles
  logical, save :: SIM_uses_Sticky
  logical, save :: SIM_uses_StickyPower
  logical, save :: SIM_uses_GayBerne
  logical, save :: SIM_uses_EAM
  logical, save :: SIM_uses_Shapes
  logical, save :: SIM_uses_FLARB
  logical, save :: SIM_uses_RF
  logical, save :: SIM_requires_postpair_calc
  logical, save :: SIM_requires_prepair_calc
  logical, save :: SIM_uses_PBC
  logical, save :: SIM_uses_molecular_cutoffs


  public :: init_FF
  public :: do_force_loop
!  public :: setRlistDF
  !public :: addInteraction
  !public :: setInteractionHash
  !public :: getInteractionHash
  public :: createInteractionMap
  public :: createGroupCutoffs

#ifdef PROFILE
  public :: getforcetime
  real, save :: forceTime = 0
  real :: forceTimeInitial, forceTimeFinal
  integer :: nLoops
#endif
  
!! Variables for cutoff mapping and interaction mapping
! Bit hash to determine pair-pair interactions.
  integer, dimension(:,:),allocatable :: InteractionHash
!! Cuttoffs in OOPSE are handled on a Group-Group pair basis.
! Largest cutoff for atypes for all potentials
  real(kind=dp), dimension(:), allocatable :: atypeMaxCuttoff
! Largest cutoff for groups 
  real(kind=dp), dimension(:), allocatable :: groupMaxCutoff
! Group to Gtype transformation Map
  integer,dimension(:), allocatable :: groupToGtype
! Group Type Max Cutoff
  real(kind=dp), dimension(:), allocatable :: gtypeMaxCutoff
! GroupType definition
  type ::gtype
     real(kind=dp) :: rcut ! Group Cutoff
     real(kind=dp) :: rcutsq ! Group Cutoff Squared
     real(kind=dp) :: rlistsq ! List cutoff Squared     
  end type gtype

  type(gtype), dimension(:,:), allocatable :: gtypeCutoffMap
  
contains

 
  subroutine createInteractionMap(status)
    integer :: nAtypes
    integer, intent(out) :: status
    integer :: i
    integer :: j
    integer :: ihash
    real(kind=dp) :: myRcut
    !! Test Types
    logical :: i_is_LJ
    logical :: i_is_Elect
    logical :: i_is_Sticky
    logical :: i_is_StickyP
    logical :: i_is_GB
    logical :: i_is_EAM
    logical :: i_is_Shape
    logical :: j_is_LJ
    logical :: j_is_Elect
    logical :: j_is_Sticky
    logical :: j_is_StickyP
    logical :: j_is_GB
    logical :: j_is_EAM
    logical :: j_is_Shape
    
    status = 0   

    if (.not. associated(atypes)) then
       call handleError("atype", "atypes was not present before call of createDefaultInteractionHash!")
       status = -1
       return
    endif
    
    nAtypes = getSize(atypes)
    
    if (nAtypes == 0) then
       status = -1
       return
    end if

    if (.not. allocated(InteractionHash)) then
       allocate(InteractionHash(nAtypes,nAtypes))
    endif
        
    do i = 1, nAtypes
       call getElementProperty(atypes, i, "is_LennardJones", i_is_LJ)
       call getElementProperty(atypes, i, "is_Electrostatic", i_is_Elect)
       call getElementProperty(atypes, i, "is_Sticky", i_is_Sticky)
       call getElementProperty(atypes, i, "is_StickyPower", i_is_StickyP)
       call getElementProperty(atypes, i, "is_GayBerne", i_is_GB)
       call getElementProperty(atypes, i, "is_EAM", i_is_EAM)
       call getElementProperty(atypes, i, "is_Shape", i_is_Shape)

       do j = i, nAtypes

          iHash = 0
          myRcut = 0.0_dp

          call getElementProperty(atypes, j, "is_LennardJones", j_is_LJ)
          call getElementProperty(atypes, j, "is_Electrostatic", j_is_Elect)
          call getElementProperty(atypes, j, "is_Sticky", j_is_Sticky)
          call getElementProperty(atypes, j, "is_StickyPower", j_is_StickyP)
          call getElementProperty(atypes, j, "is_GayBerne", j_is_GB)
          call getElementProperty(atypes, j, "is_EAM", j_is_EAM)
          call getElementProperty(atypes, j, "is_Shape", j_is_Shape)

          if (i_is_LJ .and. j_is_LJ) then
             iHash = ior(iHash, LJ_PAIR)            
          endif
          
          if (i_is_Elect .and. j_is_Elect) then
             iHash = ior(iHash, ELECTROSTATIC_PAIR)
          endif
          
          if (i_is_Sticky .and. j_is_Sticky) then
             iHash = ior(iHash, STICKY_PAIR)
          endif

          if (i_is_StickyP .and. j_is_StickyP) then
             iHash = ior(iHash, STICKYPOWER_PAIR)
          endif

          if (i_is_EAM .and. j_is_EAM) then
             iHash = ior(iHash, EAM_PAIR)
          endif

          if (i_is_GB .and. j_is_GB) iHash = ior(iHash, GAYBERNE_PAIR)
          if (i_is_GB .and. j_is_LJ) iHash = ior(iHash, GAYBERNE_LJ)
          if (i_is_LJ .and. j_is_GB) iHash = ior(iHash, GAYBERNE_LJ)

          if (i_is_Shape .and. j_is_Shape) iHash = ior(iHash, SHAPE_PAIR)
          if (i_is_Shape .and. j_is_LJ) iHash = ior(iHash, SHAPE_LJ)
          if (i_is_LJ .and. j_is_Shape) iHash = ior(iHash, SHAPE_LJ)


          InteractionHash(i,j) = iHash
          InteractionHash(j,i) = iHash

       end do

    end do

    haveInteractionMap = .true.
  end subroutine createInteractionMap

  subroutine createGroupCutoffs(skinThickness,defaultrList,stat)
    real(kind=dp), intent(in), optional :: defaultRList
    real(kind-dp), intent(in), :: skinThickenss 
  ! Query each potential and return the cutoff for that potential. We
  ! build the neighbor list based on the largest cutoff value for that
  ! atype. Each potential can decide whether to calculate the force for
  ! that atype based upon it's own cutoff.
  

    real(kind=dp), intent(in), optional :: defaultRCut, defaultSkinThickness

    integer :: iMap
    integer :: map_i,map_j
    real(kind=dp) :: thisRCut = 0.0_dp
    real(kind=dp) :: actualCutoff = 0.0_dp
    integer, intent(out) :: stat
    integer :: nAtypes
    integer :: myStatus

    stat = 0
    if (.not. haveInteractionMap) then 

       call createInteractionMap(myStatus)

       if (myStatus .ne. 0) then
          write(default_error, *) 'createInteractionMap failed in doForces!'
          stat = -1
          return
       endif
    endif

    nAtypes = getSize(atypes)
    !! If we pass a default rcut, set all atypes to that cutoff distance
    if(present(defaultRList)) then
       InteractionMap(:,:)%rCut = defaultRCut
       InteractionMap(:,:)%rCutSq = defaultRCut*defaultRCut
       InteractionMap(:,:)%rListSq = (defaultRCut+defaultSkinThickness)**2
       haveRlist = .true.
       return
    end if

    do map_i = 1,nAtypes
       do map_j = map_i,nAtypes
          iMap = InteractionMap(map_i, map_j)%InteractionHash
          
          if ( iand(iMap, LJ_PAIR).ne.0 ) then
             ! thisRCut = getLJCutOff(map_i,map_j)
             if (thisRcut > actualCutoff) actualCutoff = thisRcut
          endif
          
          if ( iand(iMap, ELECTROSTATIC_PAIR).ne.0 ) then
             ! thisRCut = getElectrostaticCutOff(map_i,map_j)
             if (thisRcut > actualCutoff) actualCutoff = thisRcut
          endif
          
          if ( iand(iMap, STICKY_PAIR).ne.0 ) then
             ! thisRCut = getStickyCutOff(map_i,map_j)
              if (thisRcut > actualCutoff) actualCutoff = thisRcut
           endif
           
           if ( iand(iMap, STICKYPOWER_PAIR).ne.0 ) then
              ! thisRCut = getStickyPowerCutOff(map_i,map_j)
              if (thisRcut > actualCutoff) actualCutoff = thisRcut
           endif
           
           if ( iand(iMap, GAYBERNE_PAIR).ne.0 ) then
              ! thisRCut = getGayberneCutOff(map_i,map_j)
              if (thisRcut > actualCutoff) actualCutoff = thisRcut
           endif
           
           if ( iand(iMap, GAYBERNE_LJ).ne.0 ) then
!              thisRCut = getGaybrneLJCutOff(map_i,map_j)
              if (thisRcut > actualCutoff) actualCutoff = thisRcut
           endif
           
           if ( iand(iMap, EAM_PAIR).ne.0 ) then       
!              thisRCut = getEAMCutOff(map_i,map_j)
              if (thisRcut > actualCutoff) actualCutoff = thisRcut
           endif
           
           if ( iand(iMap, SHAPE_PAIR).ne.0 ) then       
!              thisRCut = getShapeCutOff(map_i,map_j)
              if (thisRcut > actualCutoff) actualCutoff = thisRcut
           endif
           
           if ( iand(iMap, SHAPE_LJ).ne.0 ) then       
!              thisRCut = getShapeLJCutOff(map_i,map_j)
              if (thisRcut > actualCutoff) actualCutoff = thisRcut
           endif
           InteractionMap(map_i, map_j)%rCut = actualCutoff
           InteractionMap(map_i, map_j)%rCutSq = actualCutoff * actualCutoff
           InteractionMap(map_i, map_j)%rListSq = (actualCutoff + skinThickness)**2 

           InteractionMap(map_j, map_i)%rCut = InteractionMap(map_i, map_j)%rCut
           InteractionMap(map_j, map_i)%rCutSq = InteractionMap(map_i, map_j)%rCutSq
           InteractionMap(map_j, map_i)%rListSq = InteractionMap(map_i, map_j)%rListSq
        end do
     end do
     ! now the groups


     haveRlist = .true.
   end subroutine createGroupCutoffs

  subroutine setSimVariables()
    SIM_uses_DirectionalAtoms = SimUsesDirectionalAtoms()
    SIM_uses_LennardJones = SimUsesLennardJones()
    SIM_uses_Electrostatics = SimUsesElectrostatics()
    SIM_uses_Charges = SimUsesCharges()
    SIM_uses_Dipoles = SimUsesDipoles()
    SIM_uses_Sticky = SimUsesSticky()
    SIM_uses_StickyPower = SimUsesStickyPower()
    SIM_uses_GayBerne = SimUsesGayBerne()
    SIM_uses_EAM = SimUsesEAM()
    SIM_uses_Shapes = SimUsesShapes()
    SIM_uses_FLARB = SimUsesFLARB()
    SIM_uses_RF = SimUsesRF()
    SIM_requires_postpair_calc = SimRequiresPostpairCalc()
    SIM_requires_prepair_calc = SimRequiresPrepairCalc()
    SIM_uses_PBC = SimUsesPBC()

    haveSIMvariables = .true.

    return
  end subroutine setSimVariables

  subroutine doReadyCheck(error)
    integer, intent(out) :: error

    integer :: myStatus

    error = 0

    if (.not. haveInteractionMap) then 
       
       myStatus = 0       
       call createInteractionMap(myStatus)
       
       if (myStatus .ne. 0) then
          write(default_error, *) 'createInteractionMap failed in doForces!'
          error = -1
          return
       endif
    endif

    if (.not. haveSIMvariables) then
       call setSimVariables()
    endif

    if (.not. haveRlist) then
       write(default_error, *) 'rList has not been set in doForces!'
       error = -1
       return
    endif

    if (.not. haveNeighborList) then
       write(default_error, *) 'neighbor list has not been initialized in doForces!'
       error = -1
       return
    end if

    if (.not. haveSaneForceField) then
       write(default_error, *) 'Force Field is not sane in doForces!'
       error = -1
       return
    end if

#ifdef IS_MPI
    if (.not. isMPISimSet()) then
       write(default_error,*) "ERROR: mpiSimulation has not been initialized!"
       error = -1
       return
    endif
#endif
    return
  end subroutine doReadyCheck


  subroutine init_FF(use_RF_c, thisStat)

    logical, intent(in) :: use_RF_c

    integer, intent(out) :: thisStat   
    integer :: my_status, nMatches
    integer, pointer :: MatchList(:) => null()
    real(kind=dp) :: rcut, rrf, rt, dielect

    !! assume things are copacetic, unless they aren't
    thisStat = 0

    !! Fortran's version of a cast:
    FF_uses_RF = use_RF_c

    !! init_FF is called *after* all of the atom types have been 
    !! defined in atype_module using the new_atype subroutine.
    !!
    !! this will scan through the known atypes and figure out what
    !! interactions are used by the force field.     

    FF_uses_DirectionalAtoms = .false.
    FF_uses_LennardJones = .false.
    FF_uses_Electrostatics = .false.
    FF_uses_Charges = .false.    
    FF_uses_Dipoles = .false.
    FF_uses_Sticky = .false.
    FF_uses_StickyPower = .false.
    FF_uses_GayBerne = .false.
    FF_uses_EAM = .false.
    FF_uses_Shapes = .false.
    FF_uses_FLARB = .false.

    call getMatchingElementList(atypes, "is_Directional", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) FF_uses_DirectionalAtoms = .true.

    call getMatchingElementList(atypes, "is_LennardJones", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) FF_uses_LennardJones = .true.

    call getMatchingElementList(atypes, "is_Electrostatic", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) then
       FF_uses_Electrostatics = .true.
    endif

    call getMatchingElementList(atypes, "is_Charge", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) then
       FF_uses_Charges = .true.   
       FF_uses_Electrostatics = .true.
    endif

    call getMatchingElementList(atypes, "is_Dipole", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) then 
       FF_uses_Dipoles = .true.
       FF_uses_Electrostatics = .true.
       FF_uses_DirectionalAtoms = .true.
    endif

    call getMatchingElementList(atypes, "is_Quadrupole", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) then 
       FF_uses_Quadrupoles = .true.
       FF_uses_Electrostatics = .true.
       FF_uses_DirectionalAtoms = .true.
    endif

    call getMatchingElementList(atypes, "is_Sticky", .true., nMatches, &
         MatchList) 
    if (nMatches .gt. 0) then
       FF_uses_Sticky = .true.
       FF_uses_DirectionalAtoms = .true.
    endif

    call getMatchingElementList(atypes, "is_StickyPower", .true., nMatches, &
         MatchList) 
    if (nMatches .gt. 0) then
       FF_uses_StickyPower = .true.
       FF_uses_DirectionalAtoms = .true.
    endif
    
    call getMatchingElementList(atypes, "is_GayBerne", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) then
       FF_uses_GayBerne = .true.
       FF_uses_DirectionalAtoms = .true.
    endif

    call getMatchingElementList(atypes, "is_EAM", .true., nMatches, MatchList)
    if (nMatches .gt. 0) FF_uses_EAM = .true.

    call getMatchingElementList(atypes, "is_Shape", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) then
       FF_uses_Shapes = .true.
       FF_uses_DirectionalAtoms = .true.
    endif

    call getMatchingElementList(atypes, "is_FLARB", .true., &
         nMatches, MatchList)
    if (nMatches .gt. 0) FF_uses_FLARB = .true.

    !! Assume sanity (for the sake of argument)
    haveSaneForceField = .true.

    !! check to make sure the FF_uses_RF setting makes sense

    if (FF_uses_dipoles) then
       if (FF_uses_RF) then
          dielect = getDielect()
          call initialize_rf(dielect)
       endif
    else
       if (FF_uses_RF) then          
          write(default_error,*) 'Using Reaction Field with no dipoles?  Huh?'
          thisStat = -1
          haveSaneForceField = .false.
          return
       endif
    endif

    !sticky module does not contain check_sticky_FF anymore
    !if (FF_uses_sticky) then
    !   call check_sticky_FF(my_status)
    !   if (my_status /= 0) then
    !      thisStat = -1
    !      haveSaneForceField = .false.
    !      return
    !   end if
    !endif

    if (FF_uses_EAM) then
       call init_EAM_FF(my_status) 
       if (my_status /= 0) then
          write(default_error, *) "init_EAM_FF returned a bad status"
          thisStat = -1
          haveSaneForceField = .false.
          return
       end if
    endif

    if (FF_uses_GayBerne) then
       call check_gb_pair_FF(my_status)
       if (my_status .ne. 0) then
          thisStat = -1
          haveSaneForceField = .false.
          return
       endif
    endif

    if (FF_uses_GayBerne .and. FF_uses_LennardJones) then
    endif

    if (.not. haveNeighborList) then
       !! Create neighbor lists
       call expandNeighborList(nLocal, my_status)
       if (my_Status /= 0) then
          write(default_error,*) "SimSetup: ExpandNeighborList returned error."
          thisStat = -1
          return
       endif
       haveNeighborList = .true.
    endif

  end subroutine init_FF


  !! Does force loop over i,j pairs. Calls do_pair to calculates forces.
  !------------------------------------------------------------->
  subroutine do_force_loop(q, q_group, A, eFrame, f, t, tau, pot, &
       do_pot_c, do_stress_c, error)
    !! Position array provided by C, dimensioned by getNlocal
    real ( kind = dp ), dimension(3, nLocal) :: q
    !! molecular center-of-mass position array
    real ( kind = dp ), dimension(3, nGroups) :: q_group
    !! Rotation Matrix for each long range particle in simulation.
    real( kind = dp), dimension(9, nLocal) :: A    
    !! Unit vectors for dipoles (lab frame)
    real( kind = dp ), dimension(9,nLocal) :: eFrame
    !! Force array provided by C, dimensioned by getNlocal
    real ( kind = dp ), dimension(3,nLocal) :: f
    !! Torsion array provided by C, dimensioned by getNlocal
    real( kind = dp ), dimension(3,nLocal) :: t    

    !! Stress Tensor
    real( kind = dp), dimension(9) :: tau   
    real ( kind = dp ) :: pot
    logical ( kind = 2) :: do_pot_c, do_stress_c
    logical :: do_pot
    logical :: do_stress
    logical :: in_switching_region
#ifdef IS_MPI 
    real( kind = DP ) :: pot_local
    integer :: nAtomsInRow
    integer :: nAtomsInCol
    integer :: nprocs
    integer :: nGroupsInRow
    integer :: nGroupsInCol
#endif
    integer :: natoms    
    logical :: update_nlist   
    integer :: i, j, jstart, jend, jnab
    integer :: istart, iend
    integer :: ia, jb, atom1, atom2
    integer :: nlist
    real( kind = DP ) :: ratmsq, rgrpsq, rgrp, vpair, vij
    real( kind = DP ) :: sw, dswdr, swderiv, mf
    real(kind=dp),dimension(3) :: d_atm, d_grp, fpair, fij
    real(kind=dp) :: rfpot, mu_i, virial
    integer :: me_i, me_j, n_in_i, n_in_j
    logical :: is_dp_i
    integer :: neighborListSize
    integer :: listerror, error
    integer :: localError
    integer :: propPack_i, propPack_j
    integer :: loopStart, loopEnd, loop
    integer :: iMap
    real(kind=dp) :: listSkin = 1.0   

    !! initialize local variables  

#ifdef IS_MPI
    pot_local = 0.0_dp
    nAtomsInRow   = getNatomsInRow(plan_atom_row)
    nAtomsInCol   = getNatomsInCol(plan_atom_col)
    nGroupsInRow  = getNgroupsInRow(plan_group_row)
    nGroupsInCol  = getNgroupsInCol(plan_group_col)
#else
    natoms = nlocal
#endif

    call doReadyCheck(localError)
    if ( localError .ne. 0 ) then
       call handleError("do_force_loop", "Not Initialized")
       error = -1
       return
    end if
    call zero_work_arrays()

    do_pot = do_pot_c
    do_stress = do_stress_c

    ! Gather all information needed by all force loops:

#ifdef IS_MPI    

    call gather(q, q_Row, plan_atom_row_3d)
    call gather(q, q_Col, plan_atom_col_3d)

    call gather(q_group, q_group_Row, plan_group_row_3d)
    call gather(q_group, q_group_Col, plan_group_col_3d)

    if (FF_UsesDirectionalAtoms() .and. SIM_uses_DirectionalAtoms) then
       call gather(eFrame, eFrame_Row, plan_atom_row_rotation)
       call gather(eFrame, eFrame_Col, plan_atom_col_rotation)

       call gather(A, A_Row, plan_atom_row_rotation)
       call gather(A, A_Col, plan_atom_col_rotation)
    endif

#endif

    !! Begin force loop timing:
#ifdef PROFILE
    call cpu_time(forceTimeInitial)
    nloops = nloops + 1
#endif

    loopEnd = PAIR_LOOP
    if (FF_RequiresPrepairCalc() .and. SIM_requires_prepair_calc) then
       loopStart = PREPAIR_LOOP
    else
       loopStart = PAIR_LOOP
    endif

    do loop = loopStart, loopEnd

       ! See if we need to update neighbor lists
       ! (but only on the first time through):
       if (loop .eq. loopStart) then
#ifdef IS_MPI
          call checkNeighborList(nGroupsInRow, q_group_row, listSkin, &
               update_nlist)
#else
          call checkNeighborList(nGroups, q_group, listSkin, &
               update_nlist)
#endif
       endif

       if (update_nlist) then
          !! save current configuration and construct neighbor list
#ifdef IS_MPI
          call saveNeighborList(nGroupsInRow, q_group_row)
#else
          call saveNeighborList(nGroups, q_group)
#endif         
          neighborListSize = size(list)
          nlist = 0
       endif

       istart = 1
#ifdef IS_MPI
       iend = nGroupsInRow
#else
       iend = nGroups - 1
#endif
       outer: do i = istart, iend

#ifdef IS_MPI
             me_i = atid_row(i)
#else
             me_i = atid(i)
#endif

          if (update_nlist) point(i) = nlist + 1

          n_in_i = groupStartRow(i+1) - groupStartRow(i)

          if (update_nlist) then
#ifdef IS_MPI
             jstart = 1
             jend = nGroupsInCol
#else
             jstart = i+1
             jend = nGroups
#endif
          else             
             jstart = point(i)
             jend = point(i+1) - 1
             ! make sure group i has neighbors
             if (jstart .gt. jend) cycle outer
          endif

          do jnab = jstart, jend
             if (update_nlist) then
                j = jnab
             else
                j = list(jnab)
             endif

#ifdef IS_MPI
             me_j = atid_col(j)
             call get_interatomic_vector(q_group_Row(:,i), &
                  q_group_Col(:,j), d_grp, rgrpsq)
#else
             me_j = atid(j)
             call get_interatomic_vector(q_group(:,i), &
                  q_group(:,j), d_grp, rgrpsq)
#endif

             if (rgrpsq < InteractionMap(me_i,me_j)%rListsq) then
                if (update_nlist) then
                   nlist = nlist + 1

                   if (nlist > neighborListSize) then
#ifdef IS_MPI                 
                      call expandNeighborList(nGroupsInRow, listerror)
#else
                      call expandNeighborList(nGroups, listerror)
#endif
                      if (listerror /= 0) then
                         error = -1
                         write(DEFAULT_ERROR,*) "ERROR: nlist > list size and max allocations exceeded."
                         return
                      end if
                      neighborListSize = size(list)
                   endif

                   list(nlist) = j
                endif

                if (loop .eq. PAIR_LOOP) then
                   vij = 0.0d0
                   fij(1:3) = 0.0d0
                endif

                call get_switch(rgrpsq, sw, dswdr, rgrp, group_switch, &
                     in_switching_region)

                n_in_j = groupStartCol(j+1) - groupStartCol(j)

                do ia = groupStartRow(i), groupStartRow(i+1)-1

                   atom1 = groupListRow(ia)

                   inner: do jb = groupStartCol(j), groupStartCol(j+1)-1

                      atom2 = groupListCol(jb)

                      if (skipThisPair(atom1, atom2)) cycle inner

                      if ((n_in_i .eq. 1).and.(n_in_j .eq. 1)) then
                         d_atm(1:3) = d_grp(1:3)
                         ratmsq = rgrpsq
                      else
#ifdef IS_MPI
                         call get_interatomic_vector(q_Row(:,atom1), &
                              q_Col(:,atom2), d_atm, ratmsq)
#else
                         call get_interatomic_vector(q(:,atom1), &
                              q(:,atom2), d_atm, ratmsq)
#endif
                      endif

                      if (loop .eq. PREPAIR_LOOP) then
#ifdef IS_MPI                      
                         call do_prepair(atom1, atom2, ratmsq, d_atm, sw, &
                              rgrpsq, d_grp, do_pot, do_stress, &
                              eFrame, A, f, t, pot_local)
#else
                         call do_prepair(atom1, atom2, ratmsq, d_atm, sw, &
                              rgrpsq, d_grp, do_pot, do_stress, &
                              eFrame, A, f, t, pot)
#endif                                               
                      else
#ifdef IS_MPI                      
                         call do_pair(atom1, atom2, ratmsq, d_atm, sw, &
                              do_pot, &
                              eFrame, A, f, t, pot_local, vpair, fpair)
#else
                         call do_pair(atom1, atom2, ratmsq, d_atm, sw, &
                              do_pot,  &
                              eFrame, A, f, t, pot, vpair, fpair)
#endif

                         vij = vij + vpair
                         fij(1:3) = fij(1:3) + fpair(1:3)
                      endif
                   enddo inner
                enddo

                if (loop .eq. PAIR_LOOP) then
                   if (in_switching_region) then
                      swderiv = vij*dswdr/rgrp
                      fij(1) = fij(1) + swderiv*d_grp(1)
                      fij(2) = fij(2) + swderiv*d_grp(2)
                      fij(3) = fij(3) + swderiv*d_grp(3)

                      do ia=groupStartRow(i), groupStartRow(i+1)-1
                         atom1=groupListRow(ia)
                         mf = mfactRow(atom1)
#ifdef IS_MPI
                         f_Row(1,atom1) = f_Row(1,atom1) + swderiv*d_grp(1)*mf
                         f_Row(2,atom1) = f_Row(2,atom1) + swderiv*d_grp(2)*mf
                         f_Row(3,atom1) = f_Row(3,atom1) + swderiv*d_grp(3)*mf
#else
                         f(1,atom1) = f(1,atom1) + swderiv*d_grp(1)*mf
                         f(2,atom1) = f(2,atom1) + swderiv*d_grp(2)*mf
                         f(3,atom1) = f(3,atom1) + swderiv*d_grp(3)*mf
#endif
                      enddo

                      do jb=groupStartCol(j), groupStartCol(j+1)-1
                         atom2=groupListCol(jb)
                         mf = mfactCol(atom2)
#ifdef IS_MPI
                         f_Col(1,atom2) = f_Col(1,atom2) - swderiv*d_grp(1)*mf
                         f_Col(2,atom2) = f_Col(2,atom2) - swderiv*d_grp(2)*mf
                         f_Col(3,atom2) = f_Col(3,atom2) - swderiv*d_grp(3)*mf
#else
                         f(1,atom2) = f(1,atom2) - swderiv*d_grp(1)*mf
                         f(2,atom2) = f(2,atom2) - swderiv*d_grp(2)*mf
                         f(3,atom2) = f(3,atom2) - swderiv*d_grp(3)*mf
#endif
                      enddo
                   endif

                   if (do_stress) call add_stress_tensor(d_grp, fij)
                endif
             end if
          enddo
       enddo outer

       if (update_nlist) then
#ifdef IS_MPI
          point(nGroupsInRow + 1) = nlist + 1
#else 
          point(nGroups) = nlist + 1
#endif
          if (loop .eq. PREPAIR_LOOP) then
             ! we just did the neighbor list update on the first
             ! pass, so we don't need to do it
             ! again on the second pass
             update_nlist = .false.                              
          endif
       endif

       if (loop .eq. PREPAIR_LOOP) then
          call do_preforce(nlocal, pot)
       endif

    enddo

    !! Do timing
#ifdef PROFILE
    call cpu_time(forceTimeFinal)
    forceTime = forceTime + forceTimeFinal - forceTimeInitial
#endif    

#ifdef IS_MPI
    !!distribute forces

    f_temp = 0.0_dp
    call scatter(f_Row,f_temp,plan_atom_row_3d)
    do i = 1,nlocal
       f(1:3,i) = f(1:3,i) + f_temp(1:3,i)
    end do

    f_temp = 0.0_dp
    call scatter(f_Col,f_temp,plan_atom_col_3d)
    do i = 1,nlocal
       f(1:3,i) = f(1:3,i) + f_temp(1:3,i)
    end do

    if (FF_UsesDirectionalAtoms() .and. SIM_uses_DirectionalAtoms) then
       t_temp = 0.0_dp
       call scatter(t_Row,t_temp,plan_atom_row_3d)
       do i = 1,nlocal
          t(1:3,i) = t(1:3,i) + t_temp(1:3,i)
       end do
       t_temp = 0.0_dp
       call scatter(t_Col,t_temp,plan_atom_col_3d)

       do i = 1,nlocal
          t(1:3,i) = t(1:3,i) + t_temp(1:3,i)
       end do
    endif

    if (do_pot) then
       ! scatter/gather pot_row into the members of my column
       call scatter(pot_Row, pot_Temp, plan_atom_row)

       ! scatter/gather pot_local into all other procs
       ! add resultant to get total pot
       do i = 1, nlocal
          pot_local = pot_local + pot_Temp(i)
       enddo

       pot_Temp = 0.0_DP 

       call scatter(pot_Col, pot_Temp, plan_atom_col)
       do i = 1, nlocal
          pot_local = pot_local + pot_Temp(i)
       enddo

    endif
#endif

    if (FF_RequiresPostpairCalc() .and. SIM_requires_postpair_calc) then

       if (FF_uses_RF .and. SIM_uses_RF) then

#ifdef IS_MPI
          call scatter(rf_Row,rf,plan_atom_row_3d)
          call scatter(rf_Col,rf_Temp,plan_atom_col_3d)
          do i = 1,nlocal
             rf(1:3,i) = rf(1:3,i) + rf_Temp(1:3,i)
          end do
#endif

          do i = 1, nLocal

             rfpot = 0.0_DP
#ifdef IS_MPI
             me_i = atid_row(i)
#else
             me_i = atid(i)
#endif
             iMap = InteractionHash(me_i,me_j)
             
             if ( iand(iMap, ELECTROSTATIC_PAIR).ne.0 ) then

                mu_i = getDipoleMoment(me_i)

                !! The reaction field needs to include a self contribution 
                !! to the field:
                call accumulate_self_rf(i, mu_i, eFrame)
                !! Get the reaction field contribution to the 
                !! potential and torques:
                call reaction_field_final(i, mu_i, eFrame, rfpot, t, do_pot)
#ifdef IS_MPI
                pot_local = pot_local + rfpot
#else
                pot = pot + rfpot

#endif
             endif
          enddo
       endif
    endif


#ifdef IS_MPI

    if (do_pot) then
       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

    if (do_stress) then
       call mpi_allreduce(tau_Temp, tau, 9,mpi_double_precision,mpi_sum, &
            mpi_comm_world,mpi_err)
       call mpi_allreduce(virial_Temp, virial,1,mpi_double_precision,mpi_sum, &
            mpi_comm_world,mpi_err)
    endif

#else

    if (do_stress) then
       tau = tau_Temp
       virial = virial_Temp
    endif

#endif

  end subroutine do_force_loop

  subroutine do_pair(i, j, rijsq, d, sw, do_pot, &
       eFrame, A, f, t, pot, vpair, fpair)

    real( kind = dp ) :: pot, vpair, sw
    real( kind = dp ), dimension(3) :: fpair
    real( kind = dp ), dimension(nLocal)   :: mfact
    real( kind = dp ), dimension(9,nLocal) :: eFrame
    real( kind = dp ), dimension(9,nLocal) :: A
    real( kind = dp ), dimension(3,nLocal) :: f
    real( kind = dp ), dimension(3,nLocal) :: t

    logical, intent(inout) :: do_pot
    integer, intent(in) :: i, j
    real ( kind = dp ), intent(inout) :: rijsq
    real ( kind = dp )                :: r
    real ( kind = dp ), intent(inout) :: d(3)
    real ( kind = dp ) :: ebalance
    integer :: me_i, me_j

    integer :: iMap

    r = sqrt(rijsq)
    vpair = 0.0d0
    fpair(1:3) = 0.0d0

#ifdef IS_MPI
    me_i = atid_row(i)
    me_j = atid_col(j)
#else
    me_i = atid(i)
    me_j = atid(j)
#endif

    iMap = InteractionMap(me_i, me_j)%InteractionHash

    if ( iand(iMap, LJ_PAIR).ne.0 ) then
       call do_lj_pair(i, j, d, r, rijsq, sw, vpair, fpair, pot, f, do_pot)
    endif

    if ( iand(iMap, ELECTROSTATIC_PAIR).ne.0 ) then
       call doElectrostaticPair(i, j, d, r, rijsq, sw, vpair, fpair, &
            pot, eFrame, f, t, do_pot)

       if (FF_uses_RF .and. SIM_uses_RF) then

          ! CHECK ME (RF needs to know about all electrostatic types)
          call accumulate_rf(i, j, r, eFrame, sw)
          call rf_correct_forces(i, j, d, r, eFrame, sw, f, fpair)
       endif

    endif

    if ( iand(iMap, STICKY_PAIR).ne.0 ) then
       call do_sticky_pair(i, j, d, r, rijsq, sw, vpair, fpair, &
            pot, A, f, t, do_pot)
    endif

    if ( iand(iMap, STICKYPOWER_PAIR).ne.0 ) then
       call do_sticky_power_pair(i, j, d, r, rijsq, sw, vpair, fpair, &
            pot, A, f, t, do_pot)
    endif

    if ( iand(iMap, GAYBERNE_PAIR).ne.0 ) then
       call do_gb_pair(i, j, d, r, rijsq, sw, vpair, fpair, &
            pot, A, f, t, do_pot)
    endif
    
    if ( iand(iMap, GAYBERNE_LJ).ne.0 ) then
 !      call do_gblj_pair(i, j, d, r, rijsq, sw, vpair, fpair, &
 !           pot, A, f, t, do_pot)
    endif

    if ( iand(iMap, EAM_PAIR).ne.0 ) then       
       call do_eam_pair(i, j, d, r, rijsq, sw, vpair, fpair, pot, f, &
            do_pot)
    endif

    if ( iand(iMap, SHAPE_PAIR).ne.0 ) then       
       call do_shape_pair(i, j, d, r, rijsq, sw, vpair, fpair, &
            pot, A, f, t, do_pot)
    endif

    if ( iand(iMap, SHAPE_LJ).ne.0 ) then       
       call do_shape_pair(i, j, d, r, rijsq, sw, vpair, fpair, &
            pot, A, f, t, do_pot)
    endif
    
  end subroutine do_pair

  subroutine do_prepair(i, j, rijsq, d, sw, rcijsq, dc, &
       do_pot, do_stress, eFrame, A, f, t, pot)

    real( kind = dp ) :: pot, sw
    real( kind = dp ), dimension(9,nLocal) :: eFrame
    real (kind=dp), dimension(9,nLocal) :: A
    real (kind=dp), dimension(3,nLocal) :: f
    real (kind=dp), dimension(3,nLocal) :: t

    logical, intent(inout) :: do_pot, do_stress
    integer, intent(in) :: i, j
    real ( kind = dp ), intent(inout)    :: rijsq, rcijsq
    real ( kind = dp )                :: r, rc
    real ( kind = dp ), intent(inout) :: d(3), dc(3)

    integer :: me_i, me_j, iMap

#ifdef IS_MPI   
    me_i = atid_row(i)
    me_j = atid_col(j)   
#else   
    me_i = atid(i)
    me_j = atid(j)   
#endif

    iMap = InteractionMap(me_i, me_j)%InteractionHash

    if ( iand(iMap, EAM_PAIR).ne.0 ) then       
            call calc_EAM_prepair_rho(i, j, d, r, rijsq )
    endif
    
  end subroutine do_prepair


  subroutine do_preforce(nlocal,pot)
    integer :: nlocal
    real( kind = dp ) :: pot

    if (FF_uses_EAM .and. SIM_uses_EAM) then
       call calc_EAM_preforce_Frho(nlocal,pot)
    endif


  end subroutine do_preforce


  subroutine get_interatomic_vector(q_i, q_j, d, r_sq)

    real (kind = dp), dimension(3) :: q_i
    real (kind = dp), dimension(3) :: q_j
    real ( kind = dp ), intent(out) :: r_sq
    real( kind = dp ) :: d(3), scaled(3)
    integer i

    d(1:3) = q_j(1:3) - q_i(1:3)

    ! Wrap back into periodic box if necessary
    if ( SIM_uses_PBC ) then

       if( .not.boxIsOrthorhombic ) then
          ! calc the scaled coordinates.

          scaled = matmul(HmatInv, d)

          ! wrap the scaled coordinates

          scaled = scaled  - anint(scaled)


          ! calc the wrapped real coordinates from the wrapped scaled 
          ! coordinates

          d = matmul(Hmat,scaled)

       else
          ! calc the scaled coordinates.

          do i = 1, 3
             scaled(i) = d(i) * HmatInv(i,i)

             ! wrap the scaled coordinates

             scaled(i) = scaled(i) - anint(scaled(i))

             ! calc the wrapped real coordinates from the wrapped scaled 
             ! coordinates

             d(i) = scaled(i)*Hmat(i,i)
          enddo
       endif

    endif

    r_sq = dot_product(d,d)

  end subroutine get_interatomic_vector

  subroutine zero_work_arrays()

#ifdef IS_MPI

    q_Row = 0.0_dp
    q_Col = 0.0_dp

    q_group_Row = 0.0_dp
    q_group_Col = 0.0_dp   

    eFrame_Row = 0.0_dp
    eFrame_Col = 0.0_dp

    A_Row = 0.0_dp
    A_Col = 0.0_dp

    f_Row = 0.0_dp
    f_Col = 0.0_dp
    f_Temp = 0.0_dp

    t_Row = 0.0_dp
    t_Col = 0.0_dp
    t_Temp = 0.0_dp

    pot_Row = 0.0_dp
    pot_Col = 0.0_dp
    pot_Temp = 0.0_dp

    rf_Row = 0.0_dp
    rf_Col = 0.0_dp
    rf_Temp = 0.0_dp

#endif

    if (FF_uses_EAM .and. SIM_uses_EAM) then
       call clean_EAM()
    endif

    rf = 0.0_dp
    tau_Temp = 0.0_dp
    virial_Temp = 0.0_dp
  end subroutine zero_work_arrays

  function skipThisPair(atom1, atom2) result(skip_it)
    integer, intent(in) :: atom1
    integer, intent(in), optional :: atom2
    logical :: skip_it
    integer :: unique_id_1, unique_id_2
    integer :: me_i,me_j
    integer :: i

    skip_it = .false. 

    !! there are a number of reasons to skip a pair or a particle
    !! mostly we do this to exclude atoms who are involved in short
    !! range interactions (bonds, bends, torsions), but we also need 
    !! to exclude some overcounted interactions that result from
    !! the parallel decomposition

#ifdef IS_MPI
    !! in MPI, we have to look up the unique IDs for each atom
    unique_id_1 = AtomRowToGlobal(atom1)
#else
    !! in the normal loop, the atom numbers are unique
    unique_id_1 = atom1
#endif

    !! We were called with only one atom, so just check the global exclude
    !! list for this atom
    if (.not. present(atom2)) then
       do i = 1, nExcludes_global
          if (excludesGlobal(i) == unique_id_1) then
             skip_it = .true.
             return
          end if
       end do
       return 
    end if

#ifdef IS_MPI
    unique_id_2 = AtomColToGlobal(atom2)
#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
       skip_it = .true.
       return
    end if

    !! 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) then
          skip_it = .true.
          return
       endif
    else                
       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. &
            (excludesGlobal(i) == unique_id_2)) then
          skip_it = .true.
          return
       endif
    enddo

    do i = 1, nSkipsForAtom(atom1)
       if (skipsForAtom(atom1, i) .eq. unique_id_2) then
          skip_it = .true.
          return
       endif
    end do

    return
  end function skipThisPair

  function FF_UsesDirectionalAtoms() result(doesit)
    logical :: doesit
    doesit = FF_uses_DirectionalAtoms .or. FF_uses_Dipoles .or. &
         FF_uses_Quadrupoles .or. FF_uses_Sticky .or. &
         FF_uses_StickyPower .or. FF_uses_GayBerne .or. FF_uses_Shapes
  end function FF_UsesDirectionalAtoms

  function FF_RequiresPrepairCalc() result(doesit)
    logical :: doesit
    doesit = FF_uses_EAM
  end function FF_RequiresPrepairCalc

  function FF_RequiresPostpairCalc() result(doesit)
    logical :: doesit
    doesit = FF_uses_RF
  end function FF_RequiresPostpairCalc

#ifdef PROFILE
  function getforcetime() result(totalforcetime)
    real(kind=dp) :: totalforcetime
    totalforcetime = forcetime
  end function getforcetime
#endif

  !! This cleans componets of force arrays belonging only to fortran

  subroutine add_stress_tensor(dpair, fpair)

    real( kind = dp ), dimension(3), intent(in) :: dpair, fpair

    ! because the d vector is the rj - ri vector, and
    ! because fx, fy, fz are the force on atom i, we need a
    ! negative sign here:  

    tau_Temp(1) = tau_Temp(1) - dpair(1) * fpair(1)
    tau_Temp(2) = tau_Temp(2) - dpair(1) * fpair(2)
    tau_Temp(3) = tau_Temp(3) - dpair(1) * fpair(3)
    tau_Temp(4) = tau_Temp(4) - dpair(2) * fpair(1)
    tau_Temp(5) = tau_Temp(5) - dpair(2) * fpair(2)
    tau_Temp(6) = tau_Temp(6) - dpair(2) * fpair(3)
    tau_Temp(7) = tau_Temp(7) - dpair(3) * fpair(1)
    tau_Temp(8) = tau_Temp(8) - dpair(3) * fpair(2)
    tau_Temp(9) = tau_Temp(9) - dpair(3) * fpair(3)

    virial_Temp = virial_Temp + &
         (tau_Temp(1) + tau_Temp(5) + tau_Temp(9))

  end subroutine add_stress_tensor

end module doForces
Revision:	2269
Committed:	Tue Aug 9 19:40:56 2005 UTC (18 years, 11 months ago) by chuckv
File size:	42998 byte(s)
Log Message:	In process of re-write for group based cutoff....