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mmeineke |
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!! This Module Calculates forces due to SSD potential and VDW interactions |
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!! [Chandra and Ichiye, J. Chem. Phys. 111, 2701 (1999)]. |
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!! This module contains the Public procedures: |
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!! Corresponds to the force field defined in ssd_FF.cpp |
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!! @author Charles F. Vardeman II |
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!! @author Matthew Meineke |
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!! @author Christopher Fennel |
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!! @author J. Daniel Gezelter |
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gezelter |
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!! @version $Id: calc_sticky_pair.F90,v 1.2 2003-03-24 21:55:34 gezelter Exp $, $Date: 2003-03-24 21:55:34 $, $Name: not supported by cvs2svn $, $Revision: 1.2 $ |
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mmeineke |
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module sticky_pair |
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use force_globals |
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use definitions |
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#ifdef IS_MPI |
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use mpiSimulation |
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#endif |
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implicit none |
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PRIVATE |
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logical, save :: sticky_initialized = .false. |
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real( kind = dp ), save :: SSD_w0 |
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real( kind = dp ), save :: SSD_v0 |
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real( kind = dp ), save :: SSD_rl |
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real( kind = dp ), save :: SSD_ru |
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real( kind = dp ), save :: SSD_rup |
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public :: check_sticky_FF |
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public :: set_sticky_params |
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public :: do_sticky_pair |
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contains |
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subroutine check_sticky_FF(status) |
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integer :: status |
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status = -1 |
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if (sticky_initialized) status = 0 |
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return |
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end subroutine check_sticky_FF |
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subroutine set_sticky_params(sticky_w0, sticky_v0) |
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real( kind = dp ), intent(in) :: sticky_w0, sticky_v0 |
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! we could pass all 5 parameters if we felt like it... |
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SSD_w0 = sticky_w0 |
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SSD_v0 = sticky_v0 |
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SSD_rl = 2.75_DP |
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SSD_ru = 3.35_DP |
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SSD_rup = 4.0_DP |
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sticky_initialized = .true. |
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return |
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end subroutine set_sticky_params |
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subroutine do_sticky_pair(atom1, atom2, d, rij, r2, A, pot, f, t, & |
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do_pot, do_stress) |
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!! This routine does only the sticky portion of the SSD potential |
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!! [Chandra and Ichiye, J. Chem. Phys. 111, 2701 (1999)]. |
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!! The Lennard-Jones and dipolar interaction must be handled separately. |
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!! We assume that the rotation matrices have already been calculated |
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!! and placed in the A array. |
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!! i and j are pointers to the two SSD atoms |
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integer, intent(in) :: atom1, atom2 |
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real (kind=dp), intent(inout) :: rij, r2 |
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real (kind=dp), dimension(3), intent(in) :: d |
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real (kind=dp) :: pot |
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real (kind=dp), dimension(:,:) :: A |
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real (kind=dp), dimension(:,:) :: f |
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real (kind=dp), dimension(:,:) :: t |
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logical, intent(in) :: do_pot, do_stress |
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real (kind=dp) :: xi, yi, zi, xj, yj, zj, xi2, yi2, zi2, xj2, yj2, zj2 |
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real (kind=dp) :: r3, r5, r6, s, sp, dsdr, dspdr |
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real (kind=dp) :: wi, wj, w, wip, wjp, wp |
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real (kind=dp) :: dwidx, dwidy, dwidz, dwjdx, dwjdy, dwjdz |
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real (kind=dp) :: dwipdx, dwipdy, dwipdz, dwjpdx, dwjpdy, dwjpdz |
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real (kind=dp) :: dwidux, dwiduy, dwiduz, dwjdux, dwjduy, dwjduz |
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real (kind=dp) :: dwipdux, dwipduy, dwipduz, dwjpdux, dwjpduy, dwjpduz |
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real (kind=dp) :: zif, zis, zjf, zjs, uglyi, uglyj |
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real (kind=dp) :: drdx, drdy, drdz |
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real (kind=dp) :: txi, tyi, tzi, txj, tyj, tzj |
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real (kind=dp) :: fxii, fyii, fzii, fxjj, fyjj, fzjj |
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real (kind=dp) :: fxij, fyij, fzij, fxji, fyji, fzji |
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real (kind=dp) :: fxradial, fyradial, fzradial |
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gezelter |
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real (kind=dp) :: rijtest, rjitest |
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mmeineke |
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if (.not.sticky_initialized) then |
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write(*,*) 'Sticky forces not initialized!' |
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return |
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endif |
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r3 = r2*rij |
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r5 = r3*r2 |
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drdx = d(1) / rij |
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drdy = d(2) / rij |
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drdz = d(3) / rij |
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#ifdef IS_MPI |
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! rotate the inter-particle separation into the two different |
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! body-fixed coordinate systems: |
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xi = A_row(1,atom1)*d(1) + A_row(2,atom1)*d(2) + A_row(3,atom1)*d(3) |
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yi = A_row(4,atom1)*d(1) + A_row(5,atom1)*d(2) + A_row(6,atom1)*d(3) |
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zi = A_row(7,atom1)*d(1) + A_row(8,atom1)*d(2) + A_row(9,atom1)*d(3) |
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! negative sign because this is the vector from j to i: |
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xj = -(A_Col(1,atom2)*d(1) + A_Col(2,atom2)*d(2) + A_Col(3,atom2)*d(3)) |
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yj = -(A_Col(4,atom2)*d(1) + A_Col(5,atom2)*d(2) + A_Col(6,atom2)*d(3)) |
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zj = -(A_Col(7,atom2)*d(1) + A_Col(8,atom2)*d(2) + A_Col(9,atom2)*d(3)) |
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#else |
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! rotate the inter-particle separation into the two different |
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! body-fixed coordinate systems: |
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xi = a(1,atom1)*d(1) + a(2,atom1)*d(2) + a(3,atom1)*d(3) |
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yi = a(4,atom1)*d(1) + a(5,atom1)*d(2) + a(6,atom1)*d(3) |
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zi = a(7,atom1)*d(1) + a(8,atom1)*d(2) + a(9,atom1)*d(3) |
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! negative sign because this is the vector from j to i: |
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xj = -(a(1,atom2)*d(1) + a(2,atom2)*d(2) + a(3,atom2)*d(3)) |
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yj = -(a(4,atom2)*d(1) + a(5,atom2)*d(2) + a(6,atom2)*d(3)) |
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zj = -(a(7,atom2)*d(1) + a(8,atom2)*d(2) + a(9,atom2)*d(3)) |
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#endif |
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xi2 = xi*xi |
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yi2 = yi*yi |
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zi2 = zi*zi |
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xj2 = xj*xj |
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yj2 = yj*yj |
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zj2 = zj*zj |
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gezelter |
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mmeineke |
377 |
call calc_sw_fnc(rij, s, sp, dsdr, dspdr) |
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wi = 2.0d0*(xi2-yi2)*zi / r3 |
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wj = 2.0d0*(xj2-yj2)*zj / r3 |
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w = wi+wj |
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zif = zi/rij - 0.6d0 |
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zis = zi/rij + 0.8d0 |
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zjf = zj/rij - 0.6d0 |
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zjs = zj/rij + 0.8d0 |
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wip = zif*zif*zis*zis - SSD_w0 |
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wjp = zjf*zjf*zjs*zjs - SSD_w0 |
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wp = wip + wjp |
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if (do_pot) then |
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#ifdef IS_MPI |
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pot_row(atom1) = pot_row(atom1) + 0.25d0*SSD_v0*(s*w + sp*wp) |
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pot_col(atom2) = pot_col(atom2) + 0.25d0*SSD_v0*(s*w + sp*wp) |
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#else |
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pot = pot + 0.5d0*SSD_v0*(s*w + sp*wp) |
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#endif |
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endif |
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dwidx = 4.0d0*xi*zi/r3 - 6.0d0*xi*zi*(xi2-yi2)/r5 |
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dwidy = - 4.0d0*yi*zi/r3 - 6.0d0*yi*zi*(xi2-yi2)/r5 |
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dwidz = 2.0d0*(xi2-yi2)/r3 - 6.0d0*zi2*(xi2-yi2)/r5 |
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dwjdx = 4.0d0*xj*zj/r3 - 6.0d0*xj*zj*(xj2-yj2)/r5 |
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dwjdy = - 4.0d0*yj*zj/r3 - 6.0d0*yj*zj*(xj2-yj2)/r5 |
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dwjdz = 2.0d0*(xj2-yj2)/r3 - 6.0d0*zj2*(xj2-yj2)/r5 |
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uglyi = zif*zif*zis + zif*zis*zis |
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uglyj = zjf*zjf*zjs + zjf*zjs*zjs |
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dwipdx = -2.0d0*xi*zi*uglyi/r3 |
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dwipdy = -2.0d0*yi*zi*uglyi/r3 |
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dwipdz = 2.0d0*(1.0d0/rij - zi2/r3)*uglyi |
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dwjpdx = -2.0d0*xj*zj*uglyj/r3 |
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dwjpdy = -2.0d0*yj*zj*uglyj/r3 |
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dwjpdz = 2.0d0*(1.0d0/rij - zj2/r3)*uglyj |
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dwidux = 4.0d0*(yi*zi2 + 0.5d0*yi*(xi2-yi2))/r3 |
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dwiduy = 4.0d0*(xi*zi2 - 0.5d0*xi*(xi2-yi2))/r3 |
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dwiduz = - 8.0d0*xi*yi*zi/r3 |
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dwjdux = 4.0d0*(yj*zj2 + 0.5d0*yj*(xj2-yj2))/r3 |
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dwjduy = 4.0d0*(xj*zj2 - 0.5d0*xj*(xj2-yj2))/r3 |
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dwjduz = - 8.0d0*xj*yj*zj/r3 |
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dwipdux = 2.0d0*yi*uglyi/rij |
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dwipduy = -2.0d0*xi*uglyi/rij |
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dwipduz = 0.0d0 |
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dwjpdux = 2.0d0*yj*uglyj/rij |
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dwjpduy = -2.0d0*xj*uglyj/rij |
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dwjpduz = 0.0d0 |
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! do the torques first since they are easy: |
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! remember that these are still in the body fixed axes |
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txi = 0.5d0*SSD_v0*(s*dwidux + sp*dwipdux) |
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tyi = 0.5d0*SSD_v0*(s*dwiduy + sp*dwipduy) |
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tzi = 0.5d0*SSD_v0*(s*dwiduz + sp*dwipduz) |
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txj = 0.5d0*SSD_v0*(s*dwjdux + sp*dwjpdux) |
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tyj = 0.5d0*SSD_v0*(s*dwjduy + sp*dwjpduy) |
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tzj = 0.5d0*SSD_v0*(s*dwjduz + sp*dwjpduz) |
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! go back to lab frame using transpose of rotation matrix: |
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#ifdef IS_MPI |
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t_Row(1,atom1) = t_Row(1,atom1) + a_Row(1,atom1)*txi + & |
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a_Row(4,atom1)*tyi + a_Row(7,atom1)*tzi |
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t_Row(2,atom1) = t_Row(2,atom1) + a_Row(2,atom1)*txi + & |
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a_Row(5,atom1)*tyi + a_Row(8,atom1)*tzi |
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t_Row(3,atom1) = t_Row(3,atom1) + a_Row(3,atom1)*txi + & |
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a_Row(6,atom1)*tyi + a_Row(9,atom1)*tzi |
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t_Col(1,atom2) = t_Col(1,atom2) + a_Col(1,atom2)*txj + & |
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a_Col(4,atom2)*tyj + a_Col(7,atom2)*tzj |
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t_Col(2,atom2) = t_Col(2,atom2) + a_Col(2,atom2)*txj + & |
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a_Col(5,atom2)*tyj + a_Col(8,atom2)*tzj |
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t_Col(3,atom2) = t_Col(3,atom2) + a_Col(3,atom2)*txj + & |
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a_Col(6,atom2)*tyj + a_Col(9,atom2)*tzj |
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#else |
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t(1,atom1) = t(1,atom1) + a(1,atom1)*txi + a(4,atom1)*tyi + a(7,atom1)*tzi |
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t(2,atom1) = t(2,atom1) + a(2,atom1)*txi + a(5,atom1)*tyi + a(8,atom1)*tzi |
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t(3,atom1) = t(3,atom1) + a(3,atom1)*txi + a(6,atom1)*tyi + a(9,atom1)*tzi |
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t(1,atom2) = t(1,atom2) + a(1,atom2)*txj + a(4,atom2)*tyj + a(7,atom2)*tzj |
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t(2,atom2) = t(2,atom2) + a(2,atom2)*txj + a(5,atom2)*tyj + a(8,atom2)*tzj |
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t(3,atom2) = t(3,atom2) + a(3,atom2)*txj + a(6,atom2)*tyj + a(9,atom2)*tzj |
| 240 |
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#endif |
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! Now, on to the forces: |
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! first rotate the i terms back into the lab frame: |
| 244 |
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| 245 |
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#ifdef IS_MPI |
| 246 |
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fxii = a_Row(1,atom1)*(s*dwidx+sp*dwipdx) + & |
| 247 |
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a_Row(4,atom1)*(s*dwidy+sp*dwipdy) + & |
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a_Row(7,atom1)*(s*dwidz+sp*dwipdz) |
| 249 |
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fyii = a_Row(2,atom1)*(s*dwidx+sp*dwipdx) + & |
| 250 |
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a_Row(5,atom1)*(s*dwidy+sp*dwipdy) + & |
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a_Row(8,atom1)*(s*dwidz+sp*dwipdz) |
| 252 |
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fzii = a_Row(3,atom1)*(s*dwidx+sp*dwipdx) + & |
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a_Row(6,atom1)*(s*dwidy+sp*dwipdy) + & |
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a_Row(9,atom1)*(s*dwidz+sp*dwipdz) |
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| 256 |
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fxjj = a_Col(1,atom2)*(s*dwjdx+sp*dwjpdx) + & |
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a_Col(4,atom2)*(s*dwjdy+sp*dwjpdy) + & |
| 258 |
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a_Col(7,atom2)*(s*dwjdz+sp*dwjpdz) |
| 259 |
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fyjj = a_Col(2,atom2)*(s*dwjdx+sp*dwjpdx) + & |
| 260 |
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a_Col(5,atom2)*(s*dwjdy+sp*dwjpdy) + & |
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a_Col(8,atom2)*(s*dwjdz+sp*dwjpdz) |
| 262 |
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fzjj = a_Col(3,atom2)*(s*dwjdx+sp*dwjpdx)+ & |
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a_Col(6,atom2)*(s*dwjdy+sp*dwjpdy) + & |
| 264 |
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a_Col(9,atom2)*(s*dwjdz+sp*dwjpdz) |
| 265 |
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#else |
| 266 |
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fxii = a(1,atom1)*(s*dwidx+sp*dwipdx) + & |
| 267 |
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a(4,atom1)*(s*dwidy+sp*dwipdy) + & |
| 268 |
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a(7,atom1)*(s*dwidz+sp*dwipdz) |
| 269 |
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fyii = a(2,atom1)*(s*dwidx+sp*dwipdx) + & |
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a(5,atom1)*(s*dwidy+sp*dwipdy) + & |
| 271 |
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a(8,atom1)*(s*dwidz+sp*dwipdz) |
| 272 |
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fzii = a(3,atom1)*(s*dwidx+sp*dwipdx) + & |
| 273 |
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a(6,atom1)*(s*dwidy+sp*dwipdy) + & |
| 274 |
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a(9,atom1)*(s*dwidz+sp*dwipdz) |
| 275 |
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| 276 |
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fxjj = a(1,atom2)*(s*dwjdx+sp*dwjpdx) + & |
| 277 |
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a(4,atom2)*(s*dwjdy+sp*dwjpdy) + & |
| 278 |
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a(7,atom2)*(s*dwjdz+sp*dwjpdz) |
| 279 |
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fyjj = a(2,atom2)*(s*dwjdx+sp*dwjpdx) + & |
| 280 |
|
|
a(5,atom2)*(s*dwjdy+sp*dwjpdy) + & |
| 281 |
|
|
a(8,atom2)*(s*dwjdz+sp*dwjpdz) |
| 282 |
|
|
fzjj = a(3,atom2)*(s*dwjdx+sp*dwjpdx)+ & |
| 283 |
|
|
a(6,atom2)*(s*dwjdy+sp*dwjpdy) + & |
| 284 |
|
|
a(9,atom2)*(s*dwjdz+sp*dwjpdz) |
| 285 |
|
|
#endif |
| 286 |
|
|
|
| 287 |
|
|
fxij = -fxii |
| 288 |
|
|
fyij = -fyii |
| 289 |
|
|
fzij = -fzii |
| 290 |
|
|
|
| 291 |
|
|
fxji = -fxjj |
| 292 |
|
|
fyji = -fyjj |
| 293 |
|
|
fzji = -fzjj |
| 294 |
|
|
|
| 295 |
|
|
! now assemble these with the radial-only terms: |
| 296 |
|
|
|
| 297 |
|
|
fxradial = 0.5d0*SSD_v0*(dsdr*drdx*w + dspdr*drdx*wp + fxii + fxji) |
| 298 |
|
|
fyradial = 0.5d0*SSD_v0*(dsdr*drdy*w + dspdr*drdy*wp + fyii + fyji) |
| 299 |
|
|
fzradial = 0.5d0*SSD_v0*(dsdr*drdz*w + dspdr*drdz*wp + fzii + fzji) |
| 300 |
|
|
|
| 301 |
|
|
#ifdef IS_MPI |
| 302 |
|
|
f_Row(1,atom1) = f_Row(1,atom1) + fxradial |
| 303 |
|
|
f_Row(2,atom1) = f_Row(2,atom1) + fyradial |
| 304 |
|
|
f_Row(3,atom1) = f_Row(3,atom1) + fzradial |
| 305 |
|
|
|
| 306 |
|
|
f_Col(1,atom2) = f_Col(1,atom2) + 0.5d0*SSD_v0*(-dsdr*drdx*w - & |
| 307 |
|
|
dspdr*drdx*wp + fxjj + fxij) |
| 308 |
|
|
f_Col(2,atom2) = f_Col(2,atom2) + 0.5d0*SSD_v0*(-dsdr*drdy*w - & |
| 309 |
|
|
dspdr*drdy*wp + fyjj + fyij) |
| 310 |
|
|
f_Col(3,atom2) = f_Col(3,atom2) + 0.5d0*SSD_v0*(-dsdr*drdz*w - & |
| 311 |
|
|
dspdr*drdz*wp + fzjj + fzij) |
| 312 |
|
|
#else |
| 313 |
|
|
f(1,atom1) = f(1,atom1) + fxradial |
| 314 |
|
|
f(2,atom1) = f(2,atom1) + fyradial |
| 315 |
|
|
f(3,atom1) = f(3,atom1) + fzradial |
| 316 |
|
|
|
| 317 |
|
|
f(1,atom2) = f(1,atom2) + 0.5d0*SSD_v0*(-dsdr*drdx*w - dspdr*drdx*wp + & |
| 318 |
|
|
fxjj + fxij) |
| 319 |
|
|
f(2,atom2) = f(2,atom2) + 0.5d0*SSD_v0*(-dsdr*drdy*w - dspdr*drdy*wp + & |
| 320 |
|
|
fyjj + fyij) |
| 321 |
|
|
f(3,atom2) = f(3,atom2) + 0.5d0*SSD_v0*(-dsdr*drdz*w - dspdr*drdz*wp + & |
| 322 |
|
|
fzjj + fzij) |
| 323 |
|
|
#endif |
| 324 |
|
|
|
| 325 |
|
|
if (do_stress) then |
| 326 |
|
|
tau_Temp(1) = tau_Temp(1) + fxradial * d(1) |
| 327 |
|
|
tau_Temp(2) = tau_Temp(2) + fxradial * d(2) |
| 328 |
|
|
tau_Temp(3) = tau_Temp(3) + fxradial * d(3) |
| 329 |
|
|
tau_Temp(4) = tau_Temp(4) + fyradial * d(1) |
| 330 |
|
|
tau_Temp(5) = tau_Temp(5) + fyradial * d(2) |
| 331 |
|
|
tau_Temp(6) = tau_Temp(6) + fyradial * d(3) |
| 332 |
|
|
tau_Temp(7) = tau_Temp(7) + fzradial * d(1) |
| 333 |
|
|
tau_Temp(8) = tau_Temp(8) + fzradial * d(2) |
| 334 |
|
|
tau_Temp(9) = tau_Temp(9) + fzradial * d(3) |
| 335 |
|
|
virial_Temp = virial_Temp + (tau_Temp(1) + tau_Temp(5) + tau_Temp(9)) |
| 336 |
|
|
endif |
| 337 |
|
|
|
| 338 |
|
|
end subroutine do_sticky_pair |
| 339 |
|
|
|
| 340 |
|
|
!! calculates the switching functions and their derivatives for a given |
| 341 |
|
|
subroutine calc_sw_fnc(r, s, sp, dsdr, dspdr) |
| 342 |
|
|
|
| 343 |
|
|
real (kind=dp), intent(in) :: r |
| 344 |
|
|
real (kind=dp), intent(inout) :: s, sp, dsdr, dspdr |
| 345 |
|
|
|
| 346 |
|
|
! distances must be in angstroms |
| 347 |
|
|
|
| 348 |
|
|
if (r.lt.SSD_rl) then |
| 349 |
|
|
s = 1.0d0 |
| 350 |
|
|
sp = 1.0d0 |
| 351 |
|
|
dsdr = 0.0d0 |
| 352 |
|
|
dspdr = 0.0d0 |
| 353 |
|
|
elseif (r.gt.SSD_rup) then |
| 354 |
|
|
s = 0.0d0 |
| 355 |
|
|
sp = 0.0d0 |
| 356 |
|
|
dsdr = 0.0d0 |
| 357 |
|
|
dspdr = 0.0d0 |
| 358 |
|
|
else |
| 359 |
|
|
sp = ((SSD_rup + 2.0d0*r - 3.0d0*SSD_rl) * (SSD_rup-r)**2) / & |
| 360 |
|
|
((SSD_rup - SSD_rl)**3) |
| 361 |
|
|
dspdr = 6.0d0*(r-SSD_rup)*(r-SSD_rl)/((SSD_rup - SSD_rl)**3) |
| 362 |
|
|
|
| 363 |
|
|
if (r.gt.SSD_ru) then |
| 364 |
|
|
s = 0.0d0 |
| 365 |
|
|
dsdr = 0.0d0 |
| 366 |
|
|
else |
| 367 |
|
|
s = ((SSD_ru + 2.0d0*r - 3.0d0*SSD_rl) * (SSD_ru-r)**2) / & |
| 368 |
|
|
((SSD_ru - SSD_rl)**3) |
| 369 |
|
|
dsdr = 6.0d0*(r-SSD_ru)*(r-SSD_rl)/((SSD_ru - SSD_rl)**3) |
| 370 |
|
|
endif |
| 371 |
|
|
endif |
| 372 |
|
|
|
| 373 |
|
|
return |
| 374 |
|
|
end subroutine calc_sw_fnc |
| 375 |
|
|
end module sticky_pair |
