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Comparing trunk/OOPSE/libmdtools/calc_sticky_pair.F90 (file contents):
Revision 473 by mmeineke, Mon Apr 7 21:20:38 2003 UTC vs.
Revision 1192 by gezelter, Mon May 24 21:03:30 2004 UTC

# Line 9 | Line 9
9   !! @author Matthew Meineke
10   !! @author Christopher Fennel
11   !! @author J. Daniel Gezelter
12 < !! @version $Id: calc_sticky_pair.F90,v 1.6 2003-04-07 21:20:38 mmeineke Exp $, $Date: 2003-04-07 21:20:38 $, $Name: not supported by cvs2svn $, $Revision: 1.6 $
12 > !! @version $Id: calc_sticky_pair.F90,v 1.19 2004-05-24 21:03:25 gezelter Exp $, $Date: 2004-05-24 21:03:25 $, $Name: not supported by cvs2svn $, $Revision: 1.19 $
13  
14   module sticky_pair
15  
# Line 27 | Line 27 | module sticky_pair
27    logical, save :: sticky_initialized = .false.
28    real( kind = dp ), save :: SSD_w0 = 0.0_dp
29    real( kind = dp ), save :: SSD_v0 = 0.0_dp
30 +  real( kind = dp ), save :: SSD_v0p = 0.0_dp
31    real( kind = dp ), save :: SSD_rl = 0.0_dp
32    real( kind = dp ), save :: SSD_ru = 0.0_dp
33 +  real( kind = dp ), save :: SSD_rlp = 0.0_dp
34    real( kind = dp ), save :: SSD_rup = 0.0_dp
35 +  real( kind = dp ), save :: SSD_rbig = 0.0_dp
36  
37    public :: check_sticky_FF
38    public :: set_sticky_params
# Line 44 | Line 47 | contains
47      return
48    end subroutine check_sticky_FF
49  
50 <  subroutine set_sticky_params(sticky_w0, sticky_v0)
51 <    real( kind = dp ), intent(in) :: sticky_w0, sticky_v0
50 >  subroutine set_sticky_params(sticky_w0, sticky_v0, sticky_v0p, &
51 >       sticky_rl, sticky_ru, sticky_rlp, sticky_rup)
52 >
53 >    real( kind = dp ), intent(in) :: sticky_w0, sticky_v0, sticky_v0p
54 >    real( kind = dp ), intent(in) :: sticky_rl, sticky_ru
55 >    real( kind = dp ), intent(in) :: sticky_rlp, sticky_rup
56      
57      ! we could pass all 5 parameters if we felt like it...
58      
59      SSD_w0 = sticky_w0
60      SSD_v0 = sticky_v0
61 <    SSD_rl = 2.75_DP
62 <    SSD_ru = 3.35_DP
63 <    SSD_rup = 4.0_DP
61 >    SSD_v0p = sticky_v0p
62 >    SSD_rl = sticky_rl
63 >    SSD_ru = sticky_ru
64 >    SSD_rlp = sticky_rlp
65 >    SSD_rup = sticky_rup
66 >
67 >    if (SSD_ru .gt. SSD_rup) then
68 >       SSD_rbig = SSD_ru
69 >    else
70 >       SSD_rbig = SSD_rup
71 >    endif
72    
73      sticky_initialized = .true.
74      return
75    end subroutine set_sticky_params
76  
77 <  subroutine do_sticky_pair(atom1, atom2, d, rij, r2, A, pot, f, t, &
78 <       do_pot, do_stress)
77 >  subroutine do_sticky_pair(atom1, atom2, d, rij, r2, sw, vpair, fpair, &
78 >       pot, A, f, t, do_pot)
79      
80      !! This routine does only the sticky portion of the SSD potential
81      !! [Chandra and Ichiye, J. Chem. Phys. 111, 2701 (1999)].
# Line 68 | Line 83 | contains
83      
84      !! We assume that the rotation matrices have already been calculated
85      !! and placed in the A array.
86 <    
86 >
87      !! i and j are pointers to the two SSD atoms
88  
89      integer, intent(in) :: atom1, atom2
90      real (kind=dp), intent(inout) :: rij, r2
91      real (kind=dp), dimension(3), intent(in) :: d
92 <    real (kind=dp) :: pot
93 <    real (kind=dp), dimension(9,getNlocal()) :: A
94 <    real (kind=dp), dimension(3,getNlocal()) :: f
95 <    real (kind=dp), dimension(3,getNlocal()) :: t
96 <    logical, intent(in) :: do_pot, do_stress
92 >    real (kind=dp), dimension(3), intent(inout) :: fpair
93 >    real (kind=dp) :: pot, vpair, sw
94 >    real (kind=dp), dimension(9,nLocal) :: A
95 >    real (kind=dp), dimension(3,nLocal) :: f
96 >    real (kind=dp), dimension(3,nLocal) :: t
97 >    logical, intent(in) :: do_pot
98  
99      real (kind=dp) :: xi, yi, zi, xj, yj, zj, xi2, yi2, zi2, xj2, yj2, zj2
100      real (kind=dp) :: r3, r5, r6, s, sp, dsdr, dspdr
# Line 94 | Line 110 | contains
110      real (kind=dp) :: fxij, fyij, fzij, fxji, fyji, fzji      
111      real (kind=dp) :: fxradial, fyradial, fzradial
112      real (kind=dp) :: rijtest, rjitest
113 <      
113 >    real (kind=dp) :: radcomxi, radcomyi, radcomzi
114 >    real (kind=dp) :: radcomxj, radcomyj, radcomzj
115 >    integer :: id1, id2
116 >
117      if (.not.sticky_initialized) then
118         write(*,*) 'Sticky forces not initialized!'
119         return
120      endif
121  
103    r3 = r2*rij
104    r5 = r3*r2
105    
106    drdx = d(1) / rij
107    drdy = d(2) / rij
108    drdz = d(3) / rij
109    
110 #ifdef IS_MPI
111    ! rotate the inter-particle separation into the two different
112    ! body-fixed coordinate systems:
113    
114    xi = A_row(1,atom1)*d(1) + A_row(2,atom1)*d(2) + A_row(3,atom1)*d(3)
115    yi = A_row(4,atom1)*d(1) + A_row(5,atom1)*d(2) + A_row(6,atom1)*d(3)
116    zi = A_row(7,atom1)*d(1) + A_row(8,atom1)*d(2) + A_row(9,atom1)*d(3)
117    
118    ! negative sign because this is the vector from j to i:
119    
120    xj = -(A_Col(1,atom2)*d(1) + A_Col(2,atom2)*d(2) + A_Col(3,atom2)*d(3))
121    yj = -(A_Col(4,atom2)*d(1) + A_Col(5,atom2)*d(2) + A_Col(6,atom2)*d(3))
122    zj = -(A_Col(7,atom2)*d(1) + A_Col(8,atom2)*d(2) + A_Col(9,atom2)*d(3))
123 #else
124    ! rotate the inter-particle separation into the two different
125    ! body-fixed coordinate systems:
126    
127    xi = a(1,atom1)*d(1) + a(2,atom1)*d(2) + a(3,atom1)*d(3)
128    yi = a(4,atom1)*d(1) + a(5,atom1)*d(2) + a(6,atom1)*d(3)
129    zi = a(7,atom1)*d(1) + a(8,atom1)*d(2) + a(9,atom1)*d(3)
130    
131    ! negative sign because this is the vector from j to i:
132    
133    xj = -(a(1,atom2)*d(1) + a(2,atom2)*d(2) + a(3,atom2)*d(3))
134    yj = -(a(4,atom2)*d(1) + a(5,atom2)*d(2) + a(6,atom2)*d(3))
135    zj = -(a(7,atom2)*d(1) + a(8,atom2)*d(2) + a(9,atom2)*d(3))
136 #endif
137    
138    xi2 = xi*xi
139    yi2 = yi*yi
140    zi2 = zi*zi
141    
142    xj2 = xj*xj
143    yj2 = yj*yj
144    zj2 = zj*zj
145  
146    call calc_sw_fnc(rij, s, sp, dsdr, dspdr)
147    
148    wi = 2.0d0*(xi2-yi2)*zi / r3
149    wj = 2.0d0*(xj2-yj2)*zj / r3
150    w = wi+wj
151    
152    zif = zi/rij - 0.6d0
153    zis = zi/rij + 0.8d0
154    
155    zjf = zj/rij - 0.6d0
156    zjs = zj/rij + 0.8d0
157    
158    wip = zif*zif*zis*zis - SSD_w0
159    wjp = zjf*zjf*zjs*zjs - SSD_w0
160    wp = wip + wjp
122  
123 <    if (do_pot) then
124 < #ifdef IS_MPI
125 <       pot_row(atom1) = pot_row(atom1) + 0.25d0*SSD_v0*(s*w + sp*wp)
126 <       pot_col(atom2) = pot_col(atom2) + 0.25d0*SSD_v0*(s*w + sp*wp)
127 < #else
128 <       pot = pot + 0.5d0*SSD_v0*(s*w + sp*wp)
129 < #endif  
130 <    endif
131 <    
171 <    dwidx =   4.0d0*xi*zi/r3  - 6.0d0*xi*zi*(xi2-yi2)/r5
172 <    dwidy = - 4.0d0*yi*zi/r3  - 6.0d0*yi*zi*(xi2-yi2)/r5
173 <    dwidz =   2.0d0*(xi2-yi2)/r3  - 6.0d0*zi2*(xi2-yi2)/r5
174 <    
175 <    dwjdx =   4.0d0*xj*zj/r3  - 6.0d0*xj*zj*(xj2-yj2)/r5
176 <    dwjdy = - 4.0d0*yj*zj/r3  - 6.0d0*yj*zj*(xj2-yj2)/r5
177 <    dwjdz =   2.0d0*(xj2-yj2)/r3  - 6.0d0*zj2*(xj2-yj2)/r5
178 <    
179 <    uglyi = zif*zif*zis + zif*zis*zis
180 <    uglyj = zjf*zjf*zjs + zjf*zjs*zjs
181 <    
182 <    dwipdx = -2.0d0*xi*zi*uglyi/r3
183 <    dwipdy = -2.0d0*yi*zi*uglyi/r3
184 <    dwipdz = 2.0d0*(1.0d0/rij - zi2/r3)*uglyi
185 <    
186 <    dwjpdx = -2.0d0*xj*zj*uglyj/r3
187 <    dwjpdy = -2.0d0*yj*zj*uglyj/r3
188 <    dwjpdz = 2.0d0*(1.0d0/rij - zj2/r3)*uglyj
189 <    
190 <    dwidux = 4.0d0*(yi*zi2 + 0.5d0*yi*(xi2-yi2))/r3
191 <    dwiduy = 4.0d0*(xi*zi2 - 0.5d0*xi*(xi2-yi2))/r3
192 <    dwiduz = - 8.0d0*xi*yi*zi/r3
193 <    
194 <    dwjdux = 4.0d0*(yj*zj2 + 0.5d0*yj*(xj2-yj2))/r3
195 <    dwjduy = 4.0d0*(xj*zj2 - 0.5d0*xj*(xj2-yj2))/r3
196 <    dwjduz = - 8.0d0*xj*yj*zj/r3
197 <    
198 <    dwipdux =  2.0d0*yi*uglyi/rij
199 <    dwipduy = -2.0d0*xi*uglyi/rij
200 <    dwipduz =  0.0d0
201 <    
202 <    dwjpdux =  2.0d0*yj*uglyj/rij
203 <    dwjpduy = -2.0d0*xj*uglyj/rij
204 <    dwjpduz =  0.0d0
205 <    
206 <    ! do the torques first since they are easy:
207 <    ! remember that these are still in the body fixed axes
208 <    
209 <    txi = 0.5d0*SSD_v0*(s*dwidux + sp*dwipdux)
210 <    tyi = 0.5d0*SSD_v0*(s*dwiduy + sp*dwipduy)
211 <    tzi = 0.5d0*SSD_v0*(s*dwiduz + sp*dwipduz)
212 <    
213 <    txj = 0.5d0*SSD_v0*(s*dwjdux + sp*dwjpdux)
214 <    tyj = 0.5d0*SSD_v0*(s*dwjduy + sp*dwjpduy)
215 <    tzj = 0.5d0*SSD_v0*(s*dwjduz + sp*dwjpduz)
216 <    
217 <    ! go back to lab frame using transpose of rotation matrix:
218 <  
123 >    if ( rij .LE. SSD_rbig ) then
124 >
125 >       r3 = r2*rij
126 >       r5 = r3*r2
127 >
128 >       drdx = d(1) / rij
129 >       drdy = d(2) / rij
130 >       drdz = d(3) / rij
131 >
132   #ifdef IS_MPI
133 <    t_Row(1,atom1) = t_Row(1,atom1) + a_Row(1,atom1)*txi + &
134 <         a_Row(4,atom1)*tyi + a_Row(7,atom1)*tzi
222 <    t_Row(2,atom1) = t_Row(2,atom1) + a_Row(2,atom1)*txi + &
223 <         a_Row(5,atom1)*tyi + a_Row(8,atom1)*tzi
224 <    t_Row(3,atom1) = t_Row(3,atom1) + a_Row(3,atom1)*txi + &
225 <         a_Row(6,atom1)*tyi + a_Row(9,atom1)*tzi
226 <    
227 <    t_Col(1,atom2) = t_Col(1,atom2) + a_Col(1,atom2)*txj + &
228 <         a_Col(4,atom2)*tyj + a_Col(7,atom2)*tzj
229 <    t_Col(2,atom2) = t_Col(2,atom2) + a_Col(2,atom2)*txj + &
230 <         a_Col(5,atom2)*tyj + a_Col(8,atom2)*tzj
231 <    t_Col(3,atom2) = t_Col(3,atom2) + a_Col(3,atom2)*txj + &
232 <         a_Col(6,atom2)*tyj + a_Col(9,atom2)*tzj
233 < #else
234 <    t(1,atom1) = t(1,atom1) + a(1,atom1)*txi + a(4,atom1)*tyi + a(7,atom1)*tzi
235 <    t(2,atom1) = t(2,atom1) + a(2,atom1)*txi + a(5,atom1)*tyi + a(8,atom1)*tzi
236 <    t(3,atom1) = t(3,atom1) + a(3,atom1)*txi + a(6,atom1)*tyi + a(9,atom1)*tzi
237 <    
238 <    t(1,atom2) = t(1,atom2) + a(1,atom2)*txj + a(4,atom2)*tyj + a(7,atom2)*tzj
239 <    t(2,atom2) = t(2,atom2) + a(2,atom2)*txj + a(5,atom2)*tyj + a(8,atom2)*tzj
240 <    t(3,atom2) = t(3,atom2) + a(3,atom2)*txj + a(6,atom2)*tyj + a(9,atom2)*tzj
241 < #endif    
242 <    ! Now, on to the forces:
243 <    
244 <    ! first rotate the i terms back into the lab frame:
133 >       ! rotate the inter-particle separation into the two different
134 >       ! body-fixed coordinate systems:
135  
136 < #ifdef IS_MPI    
137 <    fxii = a_Row(1,atom1)*(s*dwidx+sp*dwipdx) + &
138 <         a_Row(4,atom1)*(s*dwidy+sp*dwipdy) + &
249 <         a_Row(7,atom1)*(s*dwidz+sp*dwipdz)
250 <    fyii = a_Row(2,atom1)*(s*dwidx+sp*dwipdx) + &
251 <         a_Row(5,atom1)*(s*dwidy+sp*dwipdy) + &
252 <         a_Row(8,atom1)*(s*dwidz+sp*dwipdz)
253 <    fzii = a_Row(3,atom1)*(s*dwidx+sp*dwipdx) + &
254 <         a_Row(6,atom1)*(s*dwidy+sp*dwipdy) + &
255 <         a_Row(9,atom1)*(s*dwidz+sp*dwipdz)
136 >       xi = A_row(1,atom1)*d(1) + A_row(2,atom1)*d(2) + A_row(3,atom1)*d(3)
137 >       yi = A_row(4,atom1)*d(1) + A_row(5,atom1)*d(2) + A_row(6,atom1)*d(3)
138 >       zi = A_row(7,atom1)*d(1) + A_row(8,atom1)*d(2) + A_row(9,atom1)*d(3)
139  
140 <    fxjj = a_Col(1,atom2)*(s*dwjdx+sp*dwjpdx) + &
141 <         a_Col(4,atom2)*(s*dwjdy+sp*dwjpdy) + &
142 <         a_Col(7,atom2)*(s*dwjdz+sp*dwjpdz)
143 <    fyjj = a_Col(2,atom2)*(s*dwjdx+sp*dwjpdx) + &
144 <         a_Col(5,atom2)*(s*dwjdy+sp*dwjpdy) + &
262 <         a_Col(8,atom2)*(s*dwjdz+sp*dwjpdz)
263 <    fzjj = a_Col(3,atom2)*(s*dwjdx+sp*dwjpdx)+ &
264 <         a_Col(6,atom2)*(s*dwjdy+sp*dwjpdy) + &
265 <         a_Col(9,atom2)*(s*dwjdz+sp*dwjpdz)
140 >       ! negative sign because this is the vector from j to i:
141 >
142 >       xj = -(A_Col(1,atom2)*d(1) + A_Col(2,atom2)*d(2) + A_Col(3,atom2)*d(3))
143 >       yj = -(A_Col(4,atom2)*d(1) + A_Col(5,atom2)*d(2) + A_Col(6,atom2)*d(3))
144 >       zj = -(A_Col(7,atom2)*d(1) + A_Col(8,atom2)*d(2) + A_Col(9,atom2)*d(3))
145   #else
146 <    fxii = a(1,atom1)*(s*dwidx+sp*dwipdx) + &
147 <         a(4,atom1)*(s*dwidy+sp*dwipdy) + &
269 <         a(7,atom1)*(s*dwidz+sp*dwipdz)
270 <    fyii = a(2,atom1)*(s*dwidx+sp*dwipdx) + &
271 <         a(5,atom1)*(s*dwidy+sp*dwipdy) + &
272 <         a(8,atom1)*(s*dwidz+sp*dwipdz)
273 <    fzii = a(3,atom1)*(s*dwidx+sp*dwipdx) + &
274 <         a(6,atom1)*(s*dwidy+sp*dwipdy) + &
275 <         a(9,atom1)*(s*dwidz+sp*dwipdz)
146 >       ! rotate the inter-particle separation into the two different
147 >       ! body-fixed coordinate systems:
148  
149 <    fxjj = a(1,atom2)*(s*dwjdx+sp*dwjpdx) + &
150 <         a(4,atom2)*(s*dwjdy+sp*dwjpdy) + &
151 <         a(7,atom2)*(s*dwjdz+sp*dwjpdz)
152 <    fyjj = a(2,atom2)*(s*dwjdx+sp*dwjpdx) + &
153 <         a(5,atom2)*(s*dwjdy+sp*dwjpdy) + &
154 <         a(8,atom2)*(s*dwjdz+sp*dwjpdz)
155 <    fzjj = a(3,atom2)*(s*dwjdx+sp*dwjpdx)+ &
156 <         a(6,atom2)*(s*dwjdy+sp*dwjpdy) + &
157 <         a(9,atom2)*(s*dwjdz+sp*dwjpdz)
149 >       xi = a(1,atom1)*d(1) + a(2,atom1)*d(2) + a(3,atom1)*d(3)
150 >       yi = a(4,atom1)*d(1) + a(5,atom1)*d(2) + a(6,atom1)*d(3)
151 >       zi = a(7,atom1)*d(1) + a(8,atom1)*d(2) + a(9,atom1)*d(3)
152 >
153 >       ! negative sign because this is the vector from j to i:
154 >
155 >       xj = -(a(1,atom2)*d(1) + a(2,atom2)*d(2) + a(3,atom2)*d(3))
156 >       yj = -(a(4,atom2)*d(1) + a(5,atom2)*d(2) + a(6,atom2)*d(3))
157 >       zj = -(a(7,atom2)*d(1) + a(8,atom2)*d(2) + a(9,atom2)*d(3))
158   #endif
287    
288    fxij = -fxii
289    fyij = -fyii
290    fzij = -fzii
291        
292    fxji = -fxjj
293    fyji = -fyjj
294    fzji = -fzjj
295    
296    ! now assemble these with the radial-only terms:
159  
160 <    fxradial = 0.5d0*SSD_v0*(dsdr*drdx*w + dspdr*drdx*wp + fxii + fxji)
161 <    fyradial = 0.5d0*SSD_v0*(dsdr*drdy*w + dspdr*drdy*wp + fyii + fyji)
162 <    fzradial = 0.5d0*SSD_v0*(dsdr*drdz*w + dspdr*drdz*wp + fzii + fzji)
163 <      
160 >       xi2 = xi*xi
161 >       yi2 = yi*yi
162 >       zi2 = zi*zi
163 >
164 >       xj2 = xj*xj
165 >       yj2 = yj*yj
166 >       zj2 = zj*zj
167 >
168 >       call calc_sw_fnc(rij, s, sp, dsdr, dspdr)
169 >
170 >       wi = 2.0d0*(xi2-yi2)*zi / r3
171 >       wj = 2.0d0*(xj2-yj2)*zj / r3
172 >       w = wi+wj
173 >
174 >       zif = zi/rij - 0.6d0
175 >       zis = zi/rij + 0.8d0
176 >
177 >       zjf = zj/rij - 0.6d0
178 >       zjs = zj/rij + 0.8d0
179 >
180 >       wip = zif*zif*zis*zis - SSD_w0
181 >       wjp = zjf*zjf*zjs*zjs - SSD_w0
182 >       wp = wip + wjp
183 >
184 >       vpair = vpair + 0.5d0*(SSD_v0*s*w + SSD_v0p*sp*wp)
185 >       if (do_pot) then
186 > #ifdef IS_MPI
187 >          pot_row(atom1) = pot_row(atom1) + 0.25d0*(SSD_v0*s*w + SSD_v0p*sp*wp)*sw
188 >          pot_col(atom2) = pot_col(atom2) + 0.25d0*(SSD_v0*s*w + SSD_v0p*sp*wp)*sw
189 > #else
190 >          pot = pot + 0.5d0*(SSD_v0*s*w + SSD_v0p*sp*wp)*sw
191 > #endif  
192 >       endif
193 >
194 >       dwidx =   4.0d0*xi*zi/r3  - 6.0d0*xi*zi*(xi2-yi2)/r5
195 >       dwidy = - 4.0d0*yi*zi/r3  - 6.0d0*yi*zi*(xi2-yi2)/r5
196 >       dwidz =   2.0d0*(xi2-yi2)/r3  - 6.0d0*zi2*(xi2-yi2)/r5
197 >
198 >       dwjdx =   4.0d0*xj*zj/r3  - 6.0d0*xj*zj*(xj2-yj2)/r5
199 >       dwjdy = - 4.0d0*yj*zj/r3  - 6.0d0*yj*zj*(xj2-yj2)/r5
200 >       dwjdz =   2.0d0*(xj2-yj2)/r3  - 6.0d0*zj2*(xj2-yj2)/r5
201 >
202 >       uglyi = zif*zif*zis + zif*zis*zis
203 >       uglyj = zjf*zjf*zjs + zjf*zjs*zjs
204 >
205 >       dwipdx = -2.0d0*xi*zi*uglyi/r3
206 >       dwipdy = -2.0d0*yi*zi*uglyi/r3
207 >       dwipdz = 2.0d0*(1.0d0/rij - zi2/r3)*uglyi
208 >
209 >       dwjpdx = -2.0d0*xj*zj*uglyj/r3
210 >       dwjpdy = -2.0d0*yj*zj*uglyj/r3
211 >       dwjpdz = 2.0d0*(1.0d0/rij - zj2/r3)*uglyj
212 >
213 >       dwidux = 4.0d0*(yi*zi2 + 0.5d0*yi*(xi2-yi2))/r3
214 >       dwiduy = 4.0d0*(xi*zi2 - 0.5d0*xi*(xi2-yi2))/r3
215 >       dwiduz = - 8.0d0*xi*yi*zi/r3
216 >
217 >       dwjdux = 4.0d0*(yj*zj2 + 0.5d0*yj*(xj2-yj2))/r3
218 >       dwjduy = 4.0d0*(xj*zj2 - 0.5d0*xj*(xj2-yj2))/r3
219 >       dwjduz = - 8.0d0*xj*yj*zj/r3
220 >
221 >       dwipdux =  2.0d0*yi*uglyi/rij
222 >       dwipduy = -2.0d0*xi*uglyi/rij
223 >       dwipduz =  0.0d0
224 >
225 >       dwjpdux =  2.0d0*yj*uglyj/rij
226 >       dwjpduy = -2.0d0*xj*uglyj/rij
227 >       dwjpduz =  0.0d0
228 >
229 >       ! do the torques first since they are easy:
230 >       ! remember that these are still in the body fixed axes
231 >
232 >       txi = 0.5d0*(SSD_v0*s*dwidux + SSD_v0p*sp*dwipdux)*sw
233 >       tyi = 0.5d0*(SSD_v0*s*dwiduy + SSD_v0p*sp*dwipduy)*sw
234 >       tzi = 0.5d0*(SSD_v0*s*dwiduz + SSD_v0p*sp*dwipduz)*sw
235 >
236 >       txj = 0.5d0*(SSD_v0*s*dwjdux + SSD_v0p*sp*dwjpdux)*sw
237 >       tyj = 0.5d0*(SSD_v0*s*dwjduy + SSD_v0p*sp*dwjpduy)*sw
238 >       tzj = 0.5d0*(SSD_v0*s*dwjduz + SSD_v0p*sp*dwjpduz)*sw
239 >
240 >       ! go back to lab frame using transpose of rotation matrix:
241 >
242   #ifdef IS_MPI
243 <    f_Row(1,atom1) = f_Row(1,atom1) + fxradial
244 <    f_Row(2,atom1) = f_Row(2,atom1) + fyradial
245 <    f_Row(3,atom1) = f_Row(3,atom1) + fzradial
246 <    
247 <    f_Col(1,atom2) = f_Col(1,atom2) - fxradial
248 <    f_Col(2,atom2) = f_Col(2,atom2) - fyradial
249 <    f_Col(3,atom2) = f_Col(3,atom2) - fzradial
243 >       t_Row(1,atom1) = t_Row(1,atom1) + a_Row(1,atom1)*txi + &
244 >            a_Row(4,atom1)*tyi + a_Row(7,atom1)*tzi
245 >       t_Row(2,atom1) = t_Row(2,atom1) + a_Row(2,atom1)*txi + &
246 >            a_Row(5,atom1)*tyi + a_Row(8,atom1)*tzi
247 >       t_Row(3,atom1) = t_Row(3,atom1) + a_Row(3,atom1)*txi + &
248 >            a_Row(6,atom1)*tyi + a_Row(9,atom1)*tzi
249 >
250 >       t_Col(1,atom2) = t_Col(1,atom2) + a_Col(1,atom2)*txj + &
251 >            a_Col(4,atom2)*tyj + a_Col(7,atom2)*tzj
252 >       t_Col(2,atom2) = t_Col(2,atom2) + a_Col(2,atom2)*txj + &
253 >            a_Col(5,atom2)*tyj + a_Col(8,atom2)*tzj
254 >       t_Col(3,atom2) = t_Col(3,atom2) + a_Col(3,atom2)*txj + &
255 >            a_Col(6,atom2)*tyj + a_Col(9,atom2)*tzj
256   #else
257 <    f(1,atom1) = f(1,atom1) - fxradial
258 <    f(2,atom1) = f(2,atom1) - fyradial
259 <    f(3,atom1) = f(3,atom1) - fzradial
260 <    
261 <    f(1,atom2) = f(1,atom2) + fxradial
262 <    f(2,atom2) = f(2,atom2) + fyradial
263 <    f(3,atom2) = f(3,atom2) + fzradial
257 >       t(1,atom1) = t(1,atom1) + a(1,atom1)*txi + a(4,atom1)*tyi + a(7,atom1)*tzi
258 >       t(2,atom1) = t(2,atom1) + a(2,atom1)*txi + a(5,atom1)*tyi + a(8,atom1)*tzi
259 >       t(3,atom1) = t(3,atom1) + a(3,atom1)*txi + a(6,atom1)*tyi + a(9,atom1)*tzi
260 >
261 >       t(1,atom2) = t(1,atom2) + a(1,atom2)*txj + a(4,atom2)*tyj + a(7,atom2)*tzj
262 >       t(2,atom2) = t(2,atom2) + a(2,atom2)*txj + a(5,atom2)*tyj + a(8,atom2)*tzj
263 >       t(3,atom2) = t(3,atom2) + a(3,atom2)*txj + a(6,atom2)*tyj + a(9,atom2)*tzj
264 > #endif    
265 >       ! Now, on to the forces:
266 >
267 >       ! first rotate the i terms back into the lab frame:
268 >
269 >       radcomxi = (SSD_v0*s*dwidx+SSD_v0p*sp*dwipdx)*sw
270 >       radcomyi = (SSD_v0*s*dwidy+SSD_v0p*sp*dwipdy)*sw
271 >       radcomzi = (SSD_v0*s*dwidz+SSD_v0p*sp*dwipdz)*sw
272 >
273 >       radcomxj = (SSD_v0*s*dwjdx+SSD_v0p*sp*dwjpdx)*sw
274 >       radcomyj = (SSD_v0*s*dwjdy+SSD_v0p*sp*dwjpdy)*sw
275 >       radcomzj = (SSD_v0*s*dwjdz+SSD_v0p*sp*dwjpdz)*sw
276 >
277 > #ifdef IS_MPI    
278 >       fxii = a_Row(1,atom1)*(radcomxi) + &
279 >            a_Row(4,atom1)*(radcomyi) + &
280 >            a_Row(7,atom1)*(radcomzi)
281 >       fyii = a_Row(2,atom1)*(radcomxi) + &
282 >            a_Row(5,atom1)*(radcomyi) + &
283 >            a_Row(8,atom1)*(radcomzi)
284 >       fzii = a_Row(3,atom1)*(radcomxi) + &
285 >            a_Row(6,atom1)*(radcomyi) + &
286 >            a_Row(9,atom1)*(radcomzi)
287 >
288 >       fxjj = a_Col(1,atom2)*(radcomxj) + &
289 >            a_Col(4,atom2)*(radcomyj) + &
290 >            a_Col(7,atom2)*(radcomzj)
291 >       fyjj = a_Col(2,atom2)*(radcomxj) + &
292 >            a_Col(5,atom2)*(radcomyj) + &
293 >            a_Col(8,atom2)*(radcomzj)
294 >       fzjj = a_Col(3,atom2)*(radcomxj)+ &
295 >            a_Col(6,atom2)*(radcomyj) + &
296 >            a_Col(9,atom2)*(radcomzj)
297 > #else
298 >       fxii = a(1,atom1)*(radcomxi) + &
299 >            a(4,atom1)*(radcomyi) + &
300 >            a(7,atom1)*(radcomzi)
301 >       fyii = a(2,atom1)*(radcomxi) + &
302 >            a(5,atom1)*(radcomyi) + &
303 >            a(8,atom1)*(radcomzi)
304 >       fzii = a(3,atom1)*(radcomxi) + &
305 >            a(6,atom1)*(radcomyi) + &
306 >            a(9,atom1)*(radcomzi)
307 >
308 >       fxjj = a(1,atom2)*(radcomxj) + &
309 >            a(4,atom2)*(radcomyj) + &
310 >            a(7,atom2)*(radcomzj)
311 >       fyjj = a(2,atom2)*(radcomxj) + &
312 >            a(5,atom2)*(radcomyj) + &
313 >            a(8,atom2)*(radcomzj)
314 >       fzjj = a(3,atom2)*(radcomxj)+ &
315 >            a(6,atom2)*(radcomyj) + &
316 >            a(9,atom2)*(radcomzj)
317   #endif
318 <    
319 <    if (do_stress) then          
320 <       tau_Temp(1) = tau_Temp(1) + fxradial * d(1)
321 <       tau_Temp(2) = tau_Temp(2) + fxradial * d(2)
322 <       tau_Temp(3) = tau_Temp(3) + fxradial * d(3)
323 <       tau_Temp(4) = tau_Temp(4) + fyradial * d(1)
324 <       tau_Temp(5) = tau_Temp(5) + fyradial * d(2)
325 <       tau_Temp(6) = tau_Temp(6) + fyradial * d(3)
326 <       tau_Temp(7) = tau_Temp(7) + fzradial * d(1)
327 <       tau_Temp(8) = tau_Temp(8) + fzradial * d(2)
328 <       tau_Temp(9) = tau_Temp(9) + fzradial * d(3)
329 <       virial_Temp = virial_Temp + (tau_Temp(1) + tau_Temp(5) + tau_Temp(9))
318 >
319 >       fxij = -fxii
320 >       fyij = -fyii
321 >       fzij = -fzii
322 >
323 >       fxji = -fxjj
324 >       fyji = -fyjj
325 >       fzji = -fzjj
326 >
327 >       ! now assemble these with the radial-only terms:
328 >
329 >       fxradial = 0.5d0*(SSD_v0*dsdr*drdx*w + SSD_v0p*dspdr*drdx*wp + fxii + fxji)
330 >       fyradial = 0.5d0*(SSD_v0*dsdr*drdy*w + SSD_v0p*dspdr*drdy*wp + fyii + fyji)
331 >       fzradial = 0.5d0*(SSD_v0*dsdr*drdz*w + SSD_v0p*dspdr*drdz*wp + fzii + fzji)
332 >
333 > #ifdef IS_MPI
334 >       f_Row(1,atom1) = f_Row(1,atom1) + fxradial
335 >       f_Row(2,atom1) = f_Row(2,atom1) + fyradial
336 >       f_Row(3,atom1) = f_Row(3,atom1) + fzradial
337 >
338 >       f_Col(1,atom2) = f_Col(1,atom2) - fxradial
339 >       f_Col(2,atom2) = f_Col(2,atom2) - fyradial
340 >       f_Col(3,atom2) = f_Col(3,atom2) - fzradial
341 > #else
342 >       f(1,atom1) = f(1,atom1) + fxradial
343 >       f(2,atom1) = f(2,atom1) + fyradial
344 >       f(3,atom1) = f(3,atom1) + fzradial
345 >
346 >       f(1,atom2) = f(1,atom2) - fxradial
347 >       f(2,atom2) = f(2,atom2) - fyradial
348 >       f(3,atom2) = f(3,atom2) - fzradial
349 > #endif
350 >
351 > #ifdef IS_MPI
352 >       id1 = tagRow(atom1)
353 >       id2 = tagColumn(atom2)
354 > #else
355 >       id1 = atom1
356 >       id2 = atom2
357 > #endif
358 >      
359 >       if (molMembershipList(id1) .ne. molMembershipList(id2)) then
360 >          
361 >          fpair(1) = fpair(1) + fxradial
362 >          fpair(2) = fpair(2) + fyradial
363 >          fpair(3) = fpair(3) + fzradial
364 >          
365 >       endif
366      endif
332  
367    end subroutine do_sticky_pair
368  
369    !! calculates the switching functions and their derivatives for a given
370    subroutine calc_sw_fnc(r, s, sp, dsdr, dspdr)
371 <          
371 >    
372      real (kind=dp), intent(in) :: r
373      real (kind=dp), intent(inout) :: s, sp, dsdr, dspdr
374 <
374 >    
375      ! distances must be in angstroms
376      
377      if (r.lt.SSD_rl) then
378         s = 1.0d0
345       sp = 1.0d0
379         dsdr = 0.0d0
380 +    elseif (r.gt.SSD_ru) then
381 +       s = 0.0d0
382 +       dsdr = 0.0d0
383 +    else
384 +       s = ((SSD_ru + 2.0d0*r - 3.0d0*SSD_rl) * (SSD_ru-r)**2) / &
385 +            ((SSD_ru - SSD_rl)**3)
386 +       dsdr = 6.0d0*(r-SSD_ru)*(r-SSD_rl)/((SSD_ru - SSD_rl)**3)
387 +    endif
388 +
389 +    if (r.lt.SSD_rlp) then
390 +       sp = 1.0d0      
391         dspdr = 0.0d0
392      elseif (r.gt.SSD_rup) then
349       s = 0.0d0
393         sp = 0.0d0
351       dsdr = 0.0d0
394         dspdr = 0.0d0
395      else
396 <       sp = ((SSD_rup + 2.0d0*r - 3.0d0*SSD_rl) * (SSD_rup-r)**2) / &
397 <            ((SSD_rup - SSD_rl)**3)
398 <       dspdr = 6.0d0*(r-SSD_rup)*(r-SSD_rl)/((SSD_rup - SSD_rl)**3)
357 <      
358 <       if (r.gt.SSD_ru) then
359 <          s = 0.0d0
360 <          dsdr = 0.0d0
361 <       else
362 <          s = ((SSD_ru + 2.0d0*r - 3.0d0*SSD_rl) * (SSD_ru-r)**2) / &
363 <               ((SSD_ru - SSD_rl)**3)
364 <          dsdr = 6.0d0*(r-SSD_ru)*(r-SSD_rl)/((SSD_ru - SSD_rl)**3)
365 <       endif
396 >       sp = ((SSD_rup + 2.0d0*r - 3.0d0*SSD_rlp) * (SSD_rup-r)**2) / &
397 >            ((SSD_rup - SSD_rlp)**3)
398 >       dspdr = 6.0d0*(r-SSD_rup)*(r-SSD_rlp)/((SSD_rup - SSD_rlp)**3)      
399      endif
400      
401      return

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