1 |
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module lj_ff |
2 |
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use simulation |
3 |
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use definitions, ONLY : dp, ndim |
4 |
+ |
#ifdef IS_MPI |
5 |
+ |
use mpiSimulation |
6 |
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#endif |
7 |
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implicit none |
8 |
+ |
PRIVATE |
9 |
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|
10 |
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!! Number of lj_atypes in lj_atype_list |
11 |
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integer, save :: n_lj_atypes = 0 |
12 |
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|
13 |
+ |
!! Starting Size for ljMixed Array |
14 |
+ |
integer, parameter :: ljMixed_blocksize = 10 |
15 |
+ |
|
16 |
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type, public :: lj_atype |
17 |
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private |
18 |
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sequence |
19 |
< |
integer :: atype_ident = 0 |
19 |
> |
!! Unique number for place in linked list |
20 |
> |
integer :: atype_number = 0 |
21 |
> |
!! Name of atype |
22 |
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character(len = 15) :: name = "NULL" |
23 |
+ |
!! Unique indentifier number (ie atomic no, etc) |
24 |
+ |
integer :: atype_ident = 0 |
25 |
+ |
!! Mass of Particle |
26 |
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real ( kind = dp ) :: mass = 0.0_dp |
27 |
+ |
!! Lennard-Jones epslon |
28 |
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real ( kind = dp ) :: epslon = 0.0_dp |
29 |
+ |
!! Lennard-Jones Sigma |
30 |
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real ( kind = dp ) :: sigma = 0.0_dp |
31 |
+ |
!! Lennard-Jones Sigma Squared |
32 |
+ |
real ( kind = dp ) :: sigma2 = 0.0_dp |
33 |
+ |
!! Lennard-Jones Sigma to sixth |
34 |
+ |
real ( kind = dp ) :: sigma6 = 0.0_dp |
35 |
+ |
!! Pointer for linked list creation |
36 |
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type (lj_atype), pointer :: next => null() |
37 |
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end type lj_atype |
38 |
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|
39 |
+ |
!! Pointer type for atype ident array |
40 |
+ |
type :: lj_atypePtr |
41 |
+ |
type (lj_atype), pointer :: this => null() |
42 |
+ |
end type lj_atypePtr |
43 |
+ |
|
44 |
+ |
!! Global list of lj atypes in simulation |
45 |
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type (lj_atype), pointer :: lj_atype_list => null() |
46 |
+ |
!! LJ mixing array |
47 |
+ |
type (lj_atype), dimension(:,:), allocatable, pointer :: ljMixed =>null() |
48 |
+ |
!! identity pointer list for force loop. |
49 |
+ |
type (lj_atypePtr), dimension(:), allocatable :: identPtrList |
50 |
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|
51 |
+ |
|
52 |
+ |
!! Neighbor list and commom arrays |
53 |
+ |
integer, allocatable, dimension(:) :: point |
54 |
+ |
integer, allocatable, dimension(:) :: list |
55 |
+ |
|
56 |
+ |
#ifdef IS_MPI |
57 |
+ |
! Universal routines: All types of force calculations will need these arrays |
58 |
+ |
! Arrays specific to a type of force calculation should be declared in that module. |
59 |
+ |
real( kind = dp ), allocatable, dimension(:,:) :: qRow |
60 |
+ |
real( kind = dp ), allocatable, dimension(:,:) :: qColumn |
61 |
+ |
|
62 |
+ |
real( kind = dp ), allocatable, dimension(:,:) :: fRow |
63 |
+ |
real( kind = dp ), allocatable, dimension(:,:) :: fColumn |
64 |
+ |
#endif |
65 |
+ |
|
66 |
+ |
|
67 |
+ |
|
68 |
+ |
|
69 |
+ |
|
70 |
+ |
|
71 |
+ |
!! Public methods and data |
72 |
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public :: new_lj_atype |
73 |
+ |
public :: do_lj_ff |
74 |
+ |
public :: getLjPot |
75 |
+ |
|
76 |
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|
77 |
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|
78 |
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|
79 |
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|
80 |
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contains |
81 |
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|
82 |
< |
subroutine new_lj_atype(name,mass,epslon,sigma,status) |
82 |
> |
subroutine new_lj_atype(name,ident,mass,epslon,sigma,status) |
83 |
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character( len = 15 ) :: name |
84 |
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real( kind = dp ), intent(in) :: mass |
85 |
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real( kind = dp ), intent(in) :: epslon |
86 |
< |
real( kind = dp ), intent(in) :: sigam |
86 |
> |
real( kind = dp ), intent(in) :: sigma |
87 |
> |
integer, intent(in) :: ident |
88 |
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integer, intent(out) :: status |
89 |
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|
90 |
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type (lj_atype), pointer :: this_lj_atype |
91 |
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type (lj_atype), pointer :: lj_atype_ptr |
92 |
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|
93 |
+ |
type (lj_atype), allocatable, dimension(:,:), pointer :: thisMix |
94 |
+ |
type (lj_atype), allocatable, dimension(:,:), pointer :: oldMix |
95 |
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integer :: alloc_error |
96 |
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integer :: atype_counter = 0 |
97 |
+ |
integer :: alloc_size |
98 |
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|
99 |
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status = 0 |
100 |
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|
101 |
+ |
|
102 |
+ |
|
103 |
+ |
! allocate a new atype |
104 |
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allocate(this_lj_atype,stat=alloc_error) |
105 |
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if (alloc_error /= 0 ) then |
106 |
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status = -1 |
112 |
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this_lj_atype%mass = mass |
113 |
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this_lj_atype%epslon = epslon |
114 |
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this_lj_atype%sigma = sigma |
115 |
+ |
this_lj_atype%sigma2 = sigma * sigma |
116 |
+ |
this_lj_atype%sigma6 = this_lj_atype%sigma2 * this_lj_atype%sigma2 & |
117 |
+ |
* this_lj_atype%sigma2 |
118 |
+ |
! assume that this atype will be successfully added |
119 |
+ |
this_lj_atype%atype_ident = ident |
120 |
+ |
this_lj_atype%number = n_lj_atypes + 1 |
121 |
|
|
122 |
|
|
123 |
+ |
! First time through allocate a array of size ljMixed_blocksize |
124 |
+ |
if(.not. associated(ljMixed)) then |
125 |
+ |
allocate(thisMix(ljMixed_blocksize,ljMixed_blocksize)) |
126 |
+ |
if (alloc_error /= 0 ) then |
127 |
+ |
status = -1 |
128 |
+ |
return |
129 |
+ |
end if |
130 |
+ |
ljMixed => thisMix |
131 |
+ |
! If we have outgrown ljMixed_blocksize, allocate a new matrix twice the size and |
132 |
+ |
! point ljMix at the new matrix. |
133 |
+ |
else if( (n_lj_atypes + 1) > size(ljMixed)) then |
134 |
+ |
alloc_size = 2*size(ljMix) |
135 |
+ |
allocate(thisMix(alloc_size,alloc_size)) |
136 |
+ |
if (alloc_error /= 0 ) then |
137 |
+ |
status = -1 |
138 |
+ |
return |
139 |
+ |
end if |
140 |
+ |
! point oldMix at old ljMixed array |
141 |
+ |
oldMix => ljMixed |
142 |
+ |
! Copy oldMix into new Mixed array |
143 |
+ |
thisMix = oldMix |
144 |
+ |
! Point ljMixed at new array |
145 |
+ |
ljMixed => thisMix |
146 |
+ |
! Free old array so we don't have a memory leak |
147 |
+ |
deallocate(oldMix) |
148 |
+ |
endif |
149 |
+ |
|
150 |
+ |
|
151 |
+ |
|
152 |
+ |
|
153 |
+ |
|
154 |
+ |
! Find bottom of atype master list |
155 |
|
! if lj_atype_list is null then we are at the top of the list. |
156 |
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if (.not. associated(lj_atype_list)) then |
157 |
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lj_atype_ptr => this_lj_atype |
158 |
|
atype_counter = 1 |
159 |
< |
else ! we need to find the bottom of the list |
159 |
> |
|
160 |
> |
else ! we need to find the bottom of the list to insert new atype |
161 |
|
lj_atype_ptr => lj_atype_list%next |
162 |
+ |
atype_counter = 1 |
163 |
|
find_end: do |
164 |
|
if (.not. associated(lj_atype_ptr%next)) then |
165 |
|
exit find_end |
166 |
|
end if |
167 |
< |
lj_atype_ptr => lj_atype_ptr%next |
167 |
> |
! Set up mixing for new atype and current atype in list |
168 |
> |
ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%sigma = & |
169 |
> |
calcLJMix("sigma",this_lj_atype%sigma, & |
170 |
> |
lj_atype_prt%sigma) |
171 |
> |
|
172 |
> |
ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%sigma2 = & |
173 |
> |
ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%sigma & |
174 |
> |
* ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%sigma |
175 |
> |
|
176 |
> |
ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%sigma6 = & |
177 |
> |
ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%sigma2 & |
178 |
> |
* ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%sigma2 & |
179 |
> |
* ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%sigma2 |
180 |
> |
|
181 |
> |
ljMix(this_lj_atype%atype_number,lj_atype_ptr%atype_number)%epslon = & |
182 |
> |
calcLJMix("epslon",this_lj_atype%epslon, & |
183 |
> |
lj_atype_prt%epslon) |
184 |
> |
|
185 |
> |
! Advance to next pointer |
186 |
> |
lj_atype_ptr => lj_atype_ptr%next |
187 |
> |
atype_counter = atype_counter + 1 |
188 |
> |
|
189 |
|
end do find_end |
190 |
|
end if |
191 |
+ |
|
192 |
+ |
|
193 |
+ |
|
194 |
|
|
195 |
+ |
! Insert new atype at end of list |
196 |
|
lj_atype_ptr => this_lj_atype |
197 |
< |
|
197 |
> |
! Increment number of atypes |
198 |
> |
|
199 |
> |
n_lj_atypes = n_lj_atypes + 1 |
200 |
> |
|
201 |
> |
! Set up self mixing |
202 |
> |
|
203 |
> |
ljMix(n_lj_atypes,n_lj_atypes)%sigma = this_lj_atype%sigma |
204 |
> |
|
205 |
> |
ljMix(n_lj_atypes,n_lj_atypes)%sigma2 = ljMix(n_lj_atypes,n_lj_atypes)%sigma & |
206 |
> |
* ljMix(n_lj_atypes,n_lj_atypes)%sigma |
207 |
> |
|
208 |
> |
ljMix(n_lj_atypes,n_lj_atypes)%sigma6 = ljMix(n_lj_atypes,n_lj_atypes)%sigma2 & |
209 |
> |
* ljMix(n_lj_atypes,n_lj_atypes)%sigma2 & |
210 |
> |
* ljMix(n_lj_atypes,n_lj_atypes)%sigma2 |
211 |
> |
|
212 |
> |
ljMix(n_lj_atypes,n_lj_atypes)%epslon = this_lj_atype%epslon |
213 |
> |
|
214 |
> |
|
215 |
|
end subroutine new_lj_atype |
216 |
|
|
71 |
– |
subroutine add_lj_atype() |
217 |
|
|
218 |
+ |
subroutine init_ljFF() |
219 |
|
|
220 |
|
|
221 |
< |
end subroutine add_lj_atype |
221 |
> |
#ifdef IS_MPI |
222 |
|
|
223 |
+ |
|
224 |
|
|
225 |
+ |
#endif |
226 |
|
|
227 |
+ |
end subroutine init_ljFF |
228 |
|
|
229 |
+ |
!! Takes an ident array and creates an atype pointer list |
230 |
+ |
!! based on those identities |
231 |
+ |
subroutine new_ljatypePtrList(mysize,ident,PtrList,status) |
232 |
+ |
integer, intent(in) :: mysize |
233 |
+ |
integer, intent(in) :: ident |
234 |
+ |
integer, optional :: status |
235 |
+ |
type(lj_atypePtr), dimension(:) :: PtrList |
236 |
+ |
|
237 |
+ |
integer :: thisIdent |
238 |
+ |
integer :: i |
239 |
+ |
integer :: alloc_error |
240 |
+ |
type (lj_atype), pointer :: tmpPtr |
241 |
+ |
|
242 |
+ |
if (present(status)) status = 0 |
243 |
+ |
|
244 |
+ |
! First time through, allocate list |
245 |
+ |
if (.not.(allocated)) then |
246 |
+ |
allocate(PtrList(mysize)) |
247 |
+ |
else |
248 |
+ |
! We want to creat a new ident list so free old list |
249 |
+ |
deallocate(PrtList) |
250 |
+ |
allocate(PtrList(mysize)) |
251 |
+ |
endif |
252 |
+ |
|
253 |
+ |
! Match pointer list |
254 |
+ |
do i = 1, mysize |
255 |
+ |
thisIdent = ident(i) |
256 |
+ |
call getLJatype(thisIdent,tmpPtr) |
257 |
+ |
|
258 |
+ |
if (.not. associated(tmpPtr)) then |
259 |
+ |
status = -1 |
260 |
+ |
return |
261 |
+ |
endif |
262 |
+ |
|
263 |
+ |
PtrList(i)%this => tmpPtr |
264 |
+ |
end do |
265 |
+ |
|
266 |
+ |
end subroutine new_ljatypePtrList |
267 |
+ |
|
268 |
+ |
!! Finds a lj_atype based upon numerical ident |
269 |
+ |
!! returns a null pointer if error |
270 |
+ |
subroutine getLJatype(ident,ljAtypePtr) |
271 |
+ |
integer, intent(in) :: ident |
272 |
+ |
type (lj_atype), intent(out),pointer :: ljAtypePtr => null() |
273 |
+ |
|
274 |
+ |
type (lj_atype), pointer :: tmplj_atype_ptr => null() |
275 |
+ |
|
276 |
+ |
if(.not. associated(lj_atype_list)) return |
277 |
+ |
|
278 |
+ |
! Point at head of list. |
279 |
+ |
tmplj_atype_ptr => lj_atype_list |
280 |
+ |
find_ident: do |
281 |
+ |
if (.not.associated(tmplj_atype_ptr)) then |
282 |
+ |
exit find_ident |
283 |
+ |
else if( lj_atype_ptr%atype_ident == ident) |
284 |
+ |
ljAtypePtr => tmplj_atype_ptr |
285 |
+ |
exit find_ident |
286 |
+ |
endif |
287 |
+ |
tmplj_atype_ptr => tmplj_atype_ptr%next |
288 |
+ |
end do find_ident |
289 |
+ |
|
290 |
+ |
end subroutine getLJatype |
291 |
+ |
|
292 |
+ |
|
293 |
+ |
! FORCE routine |
294 |
+ |
!-------------------------------------------------------------> |
295 |
+ |
subroutine do_lj_ff(q,f,potE,do_pot) |
296 |
+ |
real ( kind = dp ), dimension(ndim,) :: q |
297 |
+ |
real ( kind = dp ), dimension(ndim,nLRparticles) :: f |
298 |
+ |
real ( kind = dp ) :: potE |
299 |
+ |
|
300 |
+ |
#ifdef MPI |
301 |
+ |
real( kind = DP ), dimension(3,ncol) :: efr |
302 |
+ |
real( kind = DP ) :: pot_local |
303 |
+ |
#else |
304 |
+ |
! real( kind = DP ), dimension(3,natoms) :: efr |
305 |
+ |
#endif |
306 |
+ |
|
307 |
+ |
real( kind = DP ) :: pe |
308 |
+ |
logical, :: update_nlist |
309 |
+ |
logical :: do_pot |
310 |
+ |
|
311 |
+ |
integer :: i, j, jbeg, jend, jnab, idim, jdim, idim2, jdim2, dim, dim2 |
312 |
+ |
integer :: nlist |
313 |
+ |
integer :: j_start |
314 |
+ |
integer :: tag_i,tag_j |
315 |
+ |
real( kind = DP ) :: r, pot, ftmp, dudr, d2, drdx1, kt1, kt2, kt3, ktmp |
316 |
+ |
real( kind = DP ) :: rxi, ryi, rzi, rxij, ryij, rzij, rijsq |
317 |
+ |
|
318 |
+ |
integer :: nrow |
319 |
+ |
integer :: ncol |
320 |
+ |
|
321 |
+ |
|
322 |
+ |
|
323 |
+ |
#ifndef IS_MPI |
324 |
+ |
nrow = natoms - 1 |
325 |
+ |
ncol = natoms |
326 |
+ |
#else |
327 |
+ |
j_start = 1 |
328 |
+ |
#endif |
329 |
+ |
|
330 |
+ |
call check(update_nlist) |
331 |
+ |
|
332 |
+ |
do_pot = .false. |
333 |
+ |
if (present(pe)) do_pot = .true. |
334 |
+ |
|
335 |
+ |
#ifndef IS_MPI |
336 |
+ |
nloops = nloops + 1 |
337 |
+ |
pot = 0.0E0_DP |
338 |
+ |
f = 0.0E0_DP |
339 |
+ |
e = 0.0E0_DP |
340 |
+ |
#else |
341 |
+ |
f_row = 0.0E0_DP |
342 |
+ |
f_col = 0.0E0_DP |
343 |
+ |
|
344 |
+ |
pot_local = 0.0E0_DP |
345 |
+ |
|
346 |
+ |
e_row = 0.0E0_DP |
347 |
+ |
e_col = 0.0E0_DP |
348 |
+ |
e_tmp = 0.0E0_DP |
349 |
+ |
#endif |
350 |
+ |
efr = 0.0E0_DP |
351 |
+ |
|
352 |
+ |
! communicate MPI positions |
353 |
+ |
#ifdef MPI |
354 |
+ |
call gather(q,q_row,plan_row3) |
355 |
+ |
call gather(q,q_col,plan_col3) |
356 |
+ |
#endif |
357 |
+ |
|
358 |
+ |
#ifndef MPI |
359 |
+ |
|
360 |
+ |
#endif |
361 |
+ |
|
362 |
+ |
if (update_nlist) then |
363 |
+ |
|
364 |
+ |
! save current configuration, contruct neighbor list, |
365 |
+ |
! and calculate forces |
366 |
+ |
call save_nlist() |
367 |
+ |
|
368 |
+ |
nlist = 0 |
369 |
+ |
|
370 |
+ |
|
371 |
+ |
|
372 |
+ |
do i = 1, nrow |
373 |
+ |
point(i) = nlist + 1 |
374 |
+ |
#ifdef MPI |
375 |
+ |
tag_i = tag_row(i) |
376 |
+ |
rxi = q_row(1,i) |
377 |
+ |
ryi = q_row(2,i) |
378 |
+ |
rzi = q_row(3,i) |
379 |
+ |
#else |
380 |
+ |
j_start = i + 1 |
381 |
+ |
rxi = q(1,i) |
382 |
+ |
ryi = q(2,i) |
383 |
+ |
rzi = q(3,i) |
384 |
+ |
#endif |
385 |
+ |
|
386 |
+ |
inner: do j = j_start, ncol |
387 |
+ |
#ifdef MPI |
388 |
+ |
tag_j = tag_col(j) |
389 |
+ |
if (newtons_thrd) then |
390 |
+ |
if (tag_i <= tag_j) then |
391 |
+ |
if (mod(tag_i + tag_j,2) == 0) cycle inner |
392 |
+ |
else |
393 |
+ |
if (mod(tag_i + tag_j,2) == 1) cycle inner |
394 |
+ |
endif |
395 |
+ |
endif |
396 |
+ |
|
397 |
+ |
rxij = wrap(rxi - q_col(1,j), 1) |
398 |
+ |
ryij = wrap(ryi - q_col(2,j), 2) |
399 |
+ |
rzij = wrap(rzi - q_col(3,j), 3) |
400 |
+ |
#else |
401 |
+ |
|
402 |
+ |
rxij = wrap(rxi - q(1,j), 1) |
403 |
+ |
ryij = wrap(ryi - q(2,j), 2) |
404 |
+ |
rzij = wrap(rzi - q(3,j), 3) |
405 |
+ |
|
406 |
+ |
#endif |
407 |
+ |
rijsq = rxij*rxij + ryij*ryij + rzij*rzij |
408 |
+ |
|
409 |
+ |
#ifdef MPI |
410 |
+ |
if (rijsq <= rlstsq .AND. & |
411 |
+ |
tag_j /= tag_i) then |
412 |
+ |
#else |
413 |
+ |
if (rijsq < rlstsq) then |
414 |
+ |
#endif |
415 |
+ |
|
416 |
+ |
nlist = nlist + 1 |
417 |
+ |
if (nlist > size(list)) then |
418 |
+ |
call info("FORCE_LJ","error size list smaller then nlist") |
419 |
+ |
write(msg,*) "nlist size(list)", nlist, size(list) |
420 |
+ |
call info("FORCE_LJ",msg) |
421 |
+ |
#ifdef MPI |
422 |
+ |
call mpi_abort(MPI_COMM_WORLD,mpi_err) |
423 |
+ |
#endif |
424 |
+ |
stop |
425 |
+ |
endif |
426 |
+ |
list(nlist) = j |
427 |
+ |
|
428 |
+ |
|
429 |
+ |
if (rijsq < rcutsq) then |
430 |
+ |
|
431 |
+ |
r = dsqrt(rijsq) |
432 |
+ |
|
433 |
+ |
call LJ_mix(r,pot,dudr,d2,i,j) |
434 |
+ |
|
435 |
+ |
#ifdef MPI |
436 |
+ |
e_row(i) = e_row(i) + pot*0.5 |
437 |
+ |
e_col(i) = e_col(i) + pot*0.5 |
438 |
+ |
#else |
439 |
+ |
pe = pe + pot |
440 |
+ |
#endif |
441 |
+ |
|
442 |
+ |
efr(1,j) = -rxij |
443 |
+ |
efr(2,j) = -ryij |
444 |
+ |
efr(3,j) = -rzij |
445 |
+ |
|
446 |
+ |
do dim = 1, 3 |
447 |
+ |
|
448 |
+ |
|
449 |
+ |
drdx1 = efr(dim,j) / r |
450 |
+ |
ftmp = dudr * drdx1 |
451 |
+ |
|
452 |
+ |
|
453 |
+ |
#ifdef MPI |
454 |
+ |
f_col(dim,j) = f_col(dim,j) - ftmp |
455 |
+ |
f_row(dim,i) = f_row(dim,i) + ftmp |
456 |
+ |
#else |
457 |
+ |
|
458 |
+ |
f(dim,j) = f(dim,j) - ftmp |
459 |
+ |
f(dim,i) = f(dim,i) + ftmp |
460 |
+ |
|
461 |
+ |
#endif |
462 |
+ |
enddo |
463 |
+ |
endif |
464 |
+ |
endif |
465 |
+ |
enddo inner |
466 |
+ |
enddo |
467 |
+ |
|
468 |
+ |
#ifdef MPI |
469 |
+ |
point(nrow + 1) = nlist + 1 |
470 |
+ |
#else |
471 |
+ |
point(natoms) = nlist + 1 |
472 |
+ |
#endif |
473 |
+ |
|
474 |
+ |
else |
475 |
+ |
|
476 |
+ |
! use the list to find the neighbors |
477 |
+ |
do i = 1, nrow |
478 |
+ |
JBEG = POINT(i) |
479 |
+ |
JEND = POINT(i+1) - 1 |
480 |
+ |
! check thiat molecule i has neighbors |
481 |
+ |
if (jbeg .le. jend) then |
482 |
+ |
#ifdef MPI |
483 |
+ |
rxi = q_row(1,i) |
484 |
+ |
ryi = q_row(2,i) |
485 |
+ |
rzi = q_row(3,i) |
486 |
+ |
#else |
487 |
+ |
rxi = q(1,i) |
488 |
+ |
ryi = q(2,i) |
489 |
+ |
rzi = q(3,i) |
490 |
+ |
#endif |
491 |
+ |
do jnab = jbeg, jend |
492 |
+ |
j = list(jnab) |
493 |
+ |
#ifdef MPI |
494 |
+ |
rxij = wrap(rxi - q_col(1,j), 1) |
495 |
+ |
ryij = wrap(ryi - q_col(2,j), 2) |
496 |
+ |
rzij = wrap(rzi - q_col(3,j), 3) |
497 |
+ |
#else |
498 |
+ |
rxij = wrap(rxi - q(1,j), 1) |
499 |
+ |
ryij = wrap(ryi - q(2,j), 2) |
500 |
+ |
rzij = wrap(rzi - q(3,j), 3) |
501 |
+ |
#endif |
502 |
+ |
rijsq = rxij*rxij + ryij*ryij + rzij*rzij |
503 |
+ |
|
504 |
+ |
if (rijsq < rcutsq) then |
505 |
+ |
|
506 |
+ |
r = dsqrt(rijsq) |
507 |
+ |
|
508 |
+ |
call LJ_mix(r,pot,dudr,d2,i,j) |
509 |
+ |
#ifdef MPI |
510 |
+ |
e_row(i) = e_row(i) + pot*0.5 |
511 |
+ |
e_col(i) = e_col(i) + pot*0.5 |
512 |
+ |
#else |
513 |
+ |
if (do_pot) pe = pe + pot |
514 |
+ |
#endif |
515 |
+ |
|
516 |
+ |
|
517 |
+ |
efr(1,j) = -rxij |
518 |
+ |
efr(2,j) = -ryij |
519 |
+ |
efr(3,j) = -rzij |
520 |
+ |
|
521 |
+ |
do dim = 1, 3 |
522 |
+ |
|
523 |
+ |
drdx1 = efr(dim,j) / r |
524 |
+ |
ftmp = dudr * drdx1 |
525 |
+ |
#ifdef MPI |
526 |
+ |
f_col(dim,j) = f_col(dim,j) - ftmp |
527 |
+ |
f_row(dim,i) = f_row(dim,i) + ftmp |
528 |
+ |
#else |
529 |
+ |
f(dim,j) = f(dim,j) - ftmp |
530 |
+ |
f(dim,i) = f(dim,i) + ftmp |
531 |
+ |
#endif |
532 |
+ |
enddo |
533 |
+ |
endif |
534 |
+ |
enddo |
535 |
+ |
endif |
536 |
+ |
enddo |
537 |
+ |
endif |
538 |
+ |
|
539 |
+ |
|
540 |
+ |
|
541 |
+ |
#ifdef MPI |
542 |
+ |
!!distribute forces |
543 |
+ |
call scatter(f_row,f,plan_row3) |
544 |
+ |
|
545 |
+ |
call scatter(f_col,f_tmp,plan_col3) |
546 |
+ |
do i = 1,nlocal |
547 |
+ |
do dim = 1,3 |
548 |
+ |
f(dim,i) = f(dim,i) + f_tmp(dim,i) |
549 |
+ |
end do |
550 |
+ |
end do |
551 |
+ |
|
552 |
+ |
|
553 |
+ |
|
554 |
+ |
if (do_pot) then |
555 |
+ |
! scatter/gather pot_row into the members of my column |
556 |
+ |
call scatter(e_row,e_tmp,plan_row) |
557 |
+ |
|
558 |
+ |
! scatter/gather pot_local into all other procs |
559 |
+ |
! add resultant to get total pot |
560 |
+ |
do i = 1, nlocal |
561 |
+ |
pot_local = pot_local + e_tmp(i) |
562 |
+ |
enddo |
563 |
+ |
if (newtons_thrd) then |
564 |
+ |
e_tmp = 0.0E0_DP |
565 |
+ |
call scatter(e_col,e_tmp,plan_col) |
566 |
+ |
do i = 1, nlocal |
567 |
+ |
pot_local = pot_local + e_tmp(i) |
568 |
+ |
enddo |
569 |
+ |
endif |
570 |
+ |
endif |
571 |
+ |
#endif |
572 |
+ |
|
573 |
+ |
|
574 |
+ |
|
575 |
+ |
|
576 |
+ |
end subroutine do_lj_ff |
577 |
+ |
|
578 |
+ |
!! Calculates the potential between two lj particles, optionally returns second |
579 |
+ |
!! derivatives. |
580 |
+ |
subroutine getLjPot(r,pot,dudr,atype1,atype2,d2,status) |
581 |
+ |
! arguments |
582 |
+ |
!! Length of vector between particles |
583 |
+ |
real( kind = dp ), intent(in) :: r |
584 |
+ |
!! Potential Energy |
585 |
+ |
real( kind = dp ), intent(out) :: pot |
586 |
+ |
!! Derivatve wrt postion |
587 |
+ |
real( kind = dp ), intent(out) :: dudr |
588 |
+ |
!! Second Derivative, optional, used mainly for normal mode calculations. |
589 |
+ |
real( kind = dp ), intent(out), optional :: d2 |
590 |
+ |
|
591 |
+ |
type (lj_atype), intent(in) :: atype1 |
592 |
+ |
type (lj_atype), intent(in) :: atype2 |
593 |
+ |
|
594 |
+ |
integer, intent(out), optional :: status |
595 |
+ |
|
596 |
+ |
! local Variables |
597 |
+ |
real( kind = dp ) :: sigma |
598 |
+ |
real( kind = dp ) :: sigma2 |
599 |
+ |
real( kind = dp ) :: sigma6 |
600 |
+ |
real( kind = dp ) :: epslon |
601 |
+ |
|
602 |
+ |
real( kind = dp ) :: rcut |
603 |
+ |
real( kind = dp ) :: rcut2 |
604 |
+ |
real( kind = dp ) :: rcut6 |
605 |
+ |
real( kind = dp ) :: r2 |
606 |
+ |
real( kind = dp ) :: r6 |
607 |
+ |
|
608 |
+ |
real( kind = dp ) :: t6 |
609 |
+ |
real( kind = dp ) :: t12 |
610 |
+ |
real( kind = dp ) :: tp6 |
611 |
+ |
real( kind = dp ) :: tp12 |
612 |
+ |
real( kind = dp ) :: delta |
613 |
+ |
|
614 |
+ |
logical :: doSec = .false. |
615 |
+ |
|
616 |
+ |
integer :: errorStat |
617 |
+ |
|
618 |
+ |
!! Optional Argument Checking |
619 |
+ |
! Check to see if we need to do second derivatives |
620 |
+ |
|
621 |
+ |
if (present(d2)) doSec = .true. |
622 |
+ |
if (present(status)) status = 0 |
623 |
+ |
|
624 |
+ |
! Look up the correct parameters in the mixing matrix |
625 |
+ |
sigma = ljMixed(atype1%atype_ident,atype2_atype_ident)%sigma |
626 |
+ |
sigma2 = ljMixed(atype1%atype_ident,atype2_atype_ident)%sigma2 |
627 |
+ |
sigma6 = ljMixed(atype1%atype_ident,atype2_atype_ident)%sigma6 |
628 |
+ |
epslon = ljMixed(atype1%atype_ident,atype2_atype_ident)%epslon |
629 |
+ |
|
630 |
+ |
|
631 |
+ |
|
632 |
+ |
call getRcut(rcut,rcut2=rcut2,rcut6=rcut6,status=errorStat) |
633 |
+ |
|
634 |
+ |
r2 = r * r |
635 |
+ |
r6 = r2 * r2 * r2 |
636 |
+ |
|
637 |
+ |
t6 = sigma6/ r6 |
638 |
+ |
t12 = t6 * t6 |
639 |
+ |
|
640 |
+ |
|
641 |
+ |
|
642 |
+ |
tp6 = sigma6 / rcut6 |
643 |
+ |
tp12 = tp6*tp6 |
644 |
+ |
|
645 |
+ |
delta = -4.0E0_DP*epsilon * (tp12 - tp6) |
646 |
+ |
|
647 |
+ |
if (r.le.rcut) then |
648 |
+ |
u = 4.0E0_DP * epsilon * (t12 - t6) + delta |
649 |
+ |
dudr = 24.0E0_DP * epsilon * (t6 - 2.0E0_DP*t12) / r |
650 |
+ |
if(doSec) d2 = 24.0E0_DP * epsilon * (26.0E0_DP*t12 - 7.0E0_DP*t6)/r/r |
651 |
+ |
else |
652 |
+ |
u = 0.0E0_DP |
653 |
+ |
dudr = 0.0E0_DP |
654 |
+ |
if(doSec) d2 = 0.0E0_DP |
655 |
+ |
endif |
656 |
+ |
|
657 |
+ |
return |
658 |
+ |
|
659 |
+ |
|
660 |
+ |
|
661 |
+ |
end subroutine getLjPot |
662 |
+ |
|
663 |
+ |
|
664 |
+ |
!! Calculates the mixing for sigma or epslon based on character string |
665 |
+ |
function calcLJMix(thisParam,param1,param2,status) result(myMixParam) |
666 |
+ |
character(len=*) :: thisParam |
667 |
+ |
real(kind = dp) :: param1 |
668 |
+ |
real(kind = dp) :: param2 |
669 |
+ |
real(kind = dp ) :: myMixParam |
670 |
+ |
integer, optional :: status |
671 |
+ |
|
672 |
+ |
|
673 |
+ |
myMixParam = 0.0_dp |
674 |
+ |
|
675 |
+ |
if (present(status)) status = 0 |
676 |
+ |
|
677 |
+ |
select case (thisParam) |
678 |
+ |
|
679 |
+ |
case ("sigma") |
680 |
+ |
myMixParam = 0.5_dp * (param1 + param2) |
681 |
+ |
case ("epslon") |
682 |
+ |
myMixParam = sqrt(param1 * param2) |
683 |
+ |
case default |
684 |
+ |
status = -1 |
685 |
+ |
end select |
686 |
+ |
|
687 |
+ |
end function calcLJMix |
688 |
+ |
|
689 |
+ |
|
690 |
+ |
|
691 |
|
end module lj_ff |