Line data Source code
1 : !--------------------------------------------------------------------------------------------------!
2 : ! CP2K: A general program to perform molecular dynamics simulations !
3 : ! Copyright 2000-2025 CP2K developers group <https://cp2k.org> !
4 : ! !
5 : ! SPDX-License-Identifier: GPL-2.0-or-later !
6 : !--------------------------------------------------------------------------------------------------!
7 :
8 : ! **************************************************************************************************
9 : !> \brief Calculation of Coulomb contributions in DFTB
10 : !> \author JGH
11 : ! **************************************************************************************************
12 : MODULE qs_dftb_coulomb
13 : USE atomic_kind_types, ONLY: atomic_kind_type,&
14 : get_atomic_kind_set,&
15 : is_hydrogen
16 : USE atprop_types, ONLY: atprop_array_init,&
17 : atprop_type
18 : USE cell_types, ONLY: cell_type,&
19 : get_cell,&
20 : pbc
21 : USE cp_control_types, ONLY: dft_control_type,&
22 : dftb_control_type
23 : USE cp_dbcsr_api, ONLY: dbcsr_add,&
24 : dbcsr_get_block_p,&
25 : dbcsr_iterator_blocks_left,&
26 : dbcsr_iterator_next_block,&
27 : dbcsr_iterator_start,&
28 : dbcsr_iterator_stop,&
29 : dbcsr_iterator_type,&
30 : dbcsr_p_type
31 : USE distribution_1d_types, ONLY: distribution_1d_type
32 : USE ewald_environment_types, ONLY: ewald_env_get,&
33 : ewald_environment_type
34 : USE ewald_methods_tb, ONLY: tb_ewald_overlap,&
35 : tb_spme_evaluate
36 : USE ewald_pw_types, ONLY: ewald_pw_type
37 : USE kinds, ONLY: dp
38 : USE kpoint_types, ONLY: get_kpoint_info,&
39 : kpoint_type
40 : USE mathconstants, ONLY: oorootpi,&
41 : pi
42 : USE message_passing, ONLY: mp_para_env_type
43 : USE particle_types, ONLY: particle_type
44 : USE pw_poisson_types, ONLY: do_ewald_ewald,&
45 : do_ewald_none,&
46 : do_ewald_pme,&
47 : do_ewald_spme
48 : USE qmmm_tb_coulomb, ONLY: build_tb_coulomb_qmqm
49 : USE qs_dftb3_methods, ONLY: build_dftb3_diagonal
50 : USE qs_dftb_types, ONLY: qs_dftb_atom_type,&
51 : qs_dftb_pairpot_type
52 : USE qs_dftb_utils, ONLY: compute_block_sk,&
53 : get_dftb_atom_param
54 : USE qs_energy_types, ONLY: qs_energy_type
55 : USE qs_environment_types, ONLY: get_qs_env,&
56 : qs_environment_type
57 : USE qs_force_types, ONLY: qs_force_type
58 : USE qs_kind_types, ONLY: get_qs_kind,&
59 : qs_kind_type
60 : USE qs_neighbor_list_types, ONLY: get_iterator_info,&
61 : neighbor_list_iterate,&
62 : neighbor_list_iterator_create,&
63 : neighbor_list_iterator_p_type,&
64 : neighbor_list_iterator_release,&
65 : neighbor_list_set_p_type
66 : USE qs_rho_types, ONLY: qs_rho_get,&
67 : qs_rho_type
68 : USE sap_kind_types, ONLY: clist_type,&
69 : release_sap_int,&
70 : sap_int_type
71 : USE virial_methods, ONLY: virial_pair_force
72 : USE virial_types, ONLY: virial_type
73 : #include "./base/base_uses.f90"
74 :
75 : IMPLICIT NONE
76 :
77 : PRIVATE
78 :
79 : CHARACTER(len=*), PARAMETER, PRIVATE :: moduleN = 'qs_dftb_coulomb'
80 :
81 : ! screening for gamma function
82 : REAL(dp), PARAMETER :: tol_gamma = 1.e-4_dp
83 : ! small real number
84 : REAL(dp), PARAMETER :: rtiny = 1.e-10_dp
85 :
86 : PUBLIC :: build_dftb_coulomb, gamma_rab_sr
87 :
88 : CONTAINS
89 :
90 : ! **************************************************************************************************
91 : !> \brief ...
92 : !> \param qs_env ...
93 : !> \param ks_matrix ...
94 : !> \param rho ...
95 : !> \param mcharge ...
96 : !> \param energy ...
97 : !> \param calculate_forces ...
98 : !> \param just_energy ...
99 : ! **************************************************************************************************
100 12036 : SUBROUTINE build_dftb_coulomb(qs_env, ks_matrix, rho, mcharge, energy, &
101 : calculate_forces, just_energy)
102 :
103 : TYPE(qs_environment_type), POINTER :: qs_env
104 : TYPE(dbcsr_p_type), DIMENSION(:, :), POINTER :: ks_matrix
105 : TYPE(qs_rho_type), POINTER :: rho
106 : REAL(dp), DIMENSION(:) :: mcharge
107 : TYPE(qs_energy_type), POINTER :: energy
108 : LOGICAL, INTENT(in) :: calculate_forces, just_energy
109 :
110 : CHARACTER(len=*), PARAMETER :: routineN = 'build_dftb_coulomb'
111 :
112 : INTEGER :: atom_i, atom_j, ewald_type, handle, i, ia, iac, iatom, ic, icol, ikind, img, &
113 : irow, is, jatom, jkind, natom, natorb_a, natorb_b, nimg, nkind, nmat
114 12036 : INTEGER, ALLOCATABLE, DIMENSION(:) :: atom_of_kind, kind_of
115 : INTEGER, DIMENSION(3) :: cellind, periodic
116 12036 : INTEGER, DIMENSION(:, :, :), POINTER :: cell_to_index
117 : LOGICAL :: defined, do_ewald, do_gamma_stress, &
118 : found, hb_sr_damp, use_virial
119 : REAL(KIND=dp) :: alpha, ddr, deth, dgam, dr, drm, drp, &
120 : fi, ga, gb, gmat, gmij, hb_para, zeff
121 12036 : REAL(KIND=dp), ALLOCATABLE, DIMENSION(:) :: xgamma, zeffk
122 : REAL(KIND=dp), DIMENSION(0:3) :: eta_a, eta_b
123 : REAL(KIND=dp), DIMENSION(3) :: fij, rij
124 12036 : REAL(KIND=dp), DIMENSION(:, :), POINTER :: dsblock, gmcharge, ksblock, pblock, &
125 12036 : sblock
126 12036 : REAL(KIND=dp), DIMENSION(:, :, :), POINTER :: dsint
127 12036 : TYPE(atomic_kind_type), DIMENSION(:), POINTER :: atomic_kind_set
128 : TYPE(atprop_type), POINTER :: atprop
129 : TYPE(cell_type), POINTER :: cell
130 : TYPE(dbcsr_iterator_type) :: iter
131 12036 : TYPE(dbcsr_p_type), DIMENSION(:, :), POINTER :: matrix_p, matrix_s
132 : TYPE(dft_control_type), POINTER :: dft_control
133 : TYPE(distribution_1d_type), POINTER :: local_particles
134 : TYPE(ewald_environment_type), POINTER :: ewald_env
135 : TYPE(ewald_pw_type), POINTER :: ewald_pw
136 : TYPE(kpoint_type), POINTER :: kpoints
137 : TYPE(mp_para_env_type), POINTER :: para_env
138 : TYPE(neighbor_list_iterator_p_type), &
139 12036 : DIMENSION(:), POINTER :: nl_iterator
140 : TYPE(neighbor_list_set_p_type), DIMENSION(:), &
141 12036 : POINTER :: n_list
142 12036 : TYPE(particle_type), DIMENSION(:), POINTER :: particle_set
143 : TYPE(qs_dftb_atom_type), POINTER :: dftb_kind, dftb_kind_a, dftb_kind_b
144 : TYPE(qs_dftb_pairpot_type), DIMENSION(:, :), &
145 12036 : POINTER :: dftb_potential
146 12036 : TYPE(qs_force_type), DIMENSION(:), POINTER :: force
147 12036 : TYPE(qs_kind_type), DIMENSION(:), POINTER :: qs_kind_set
148 12036 : TYPE(sap_int_type), DIMENSION(:), POINTER :: sap_int
149 : TYPE(virial_type), POINTER :: virial
150 :
151 12036 : CALL timeset(routineN, handle)
152 :
153 12036 : NULLIFY (matrix_p, matrix_s, virial, atprop, dft_control)
154 :
155 12036 : use_virial = .FALSE.
156 :
157 12036 : IF (calculate_forces) THEN
158 : nmat = 4
159 : ELSE
160 11420 : nmat = 1
161 : END IF
162 :
163 12036 : CALL get_qs_env(qs_env, nkind=nkind, natom=natom)
164 48144 : ALLOCATE (gmcharge(natom, nmat))
165 232596 : gmcharge = 0._dp
166 :
167 : CALL get_qs_env(qs_env, &
168 : particle_set=particle_set, &
169 : cell=cell, &
170 : virial=virial, &
171 : atprop=atprop, &
172 : dft_control=dft_control, &
173 : atomic_kind_set=atomic_kind_set, &
174 : qs_kind_set=qs_kind_set, &
175 12036 : force=force, para_env=para_env)
176 :
177 12036 : IF (calculate_forces) THEN
178 1126 : use_virial = virial%pv_availability .AND. (.NOT. virial%pv_numer)
179 : END IF
180 :
181 12036 : NULLIFY (dftb_potential)
182 12036 : CALL get_qs_env(qs_env=qs_env, dftb_potential=dftb_potential)
183 12036 : NULLIFY (n_list)
184 12036 : CALL get_qs_env(qs_env=qs_env, sab_orb=n_list)
185 12036 : CALL neighbor_list_iterator_create(nl_iterator, n_list)
186 2456773 : DO WHILE (neighbor_list_iterate(nl_iterator) == 0)
187 : CALL get_iterator_info(nl_iterator, ikind=ikind, jkind=jkind, &
188 2444737 : iatom=iatom, jatom=jatom, r=rij, cell=cellind)
189 :
190 2444737 : CALL get_qs_kind(qs_kind_set(ikind), dftb_parameter=dftb_kind_a)
191 : CALL get_dftb_atom_param(dftb_kind_a, &
192 2444737 : defined=defined, eta=eta_a, natorb=natorb_a)
193 2444737 : IF (.NOT. defined .OR. natorb_a < 1) CYCLE
194 2444737 : CALL get_qs_kind(qs_kind_set(jkind), dftb_parameter=dftb_kind_b)
195 : CALL get_dftb_atom_param(dftb_kind_b, &
196 2444737 : defined=defined, eta=eta_b, natorb=natorb_b)
197 2444737 : IF (.NOT. defined .OR. natorb_b < 1) CYCLE
198 :
199 : ! gamma matrix
200 2444737 : hb_sr_damp = dft_control%qs_control%dftb_control%hb_sr_damp
201 2444737 : IF (hb_sr_damp) THEN
202 : ! short range correction enabled only when iatom XOR jatom are hydrogens
203 : hb_sr_damp = is_hydrogen(particle_set(iatom)%atomic_kind) .NEQV. &
204 1082409 : is_hydrogen(particle_set(jatom)%atomic_kind)
205 : END IF
206 1082409 : IF (hb_sr_damp) THEN
207 439322 : hb_para = dft_control%qs_control%dftb_control%hb_sr_para
208 : ELSE
209 2005415 : hb_para = 0.0_dp
210 : END IF
211 2444737 : ga = eta_a(0)
212 2444737 : gb = eta_b(0)
213 9778948 : dr = SQRT(SUM(rij(:)**2))
214 2444737 : gmat = gamma_rab_sr(dr, ga, gb, hb_para)
215 2444737 : gmcharge(jatom, 1) = gmcharge(jatom, 1) + gmat*mcharge(iatom)
216 2444737 : IF (iatom /= jatom) THEN
217 2300710 : gmcharge(iatom, 1) = gmcharge(iatom, 1) + gmat*mcharge(jatom)
218 : END IF
219 2456773 : IF (calculate_forces .AND. (iatom /= jatom .OR. dr > 0.001_dp)) THEN
220 253111 : ddr = 0.1_dp*dftb_potential(ikind, jkind)%dgrd
221 253111 : drp = dr + ddr
222 253111 : drm = dr - ddr
223 253111 : dgam = 0.5_dp*(gamma_rab_sr(drp, ga, gb, hb_para) - gamma_rab_sr(drm, ga, gb, hb_para))/ddr
224 1012444 : DO i = 1, 3
225 759333 : gmcharge(jatom, i + 1) = gmcharge(jatom, i + 1) - dgam*mcharge(iatom)*rij(i)/dr
226 759333 : IF (dr > 0.001_dp) THEN
227 759333 : gmcharge(iatom, i + 1) = gmcharge(iatom, i + 1) + dgam*mcharge(jatom)*rij(i)/dr
228 : END IF
229 1012444 : IF (use_virial) THEN
230 507639 : fij(i) = -mcharge(iatom)*mcharge(jatom)*dgam*rij(i)/dr
231 : END IF
232 : END DO
233 253111 : IF (use_virial) THEN
234 169213 : fi = 1.0_dp
235 169213 : IF (iatom == jatom) fi = 0.5_dp
236 169213 : CALL virial_pair_force(virial%pv_virial, fi, fij, rij)
237 : END IF
238 : END IF
239 : END DO
240 12036 : CALL neighbor_list_iterator_release(nl_iterator)
241 :
242 12036 : IF (atprop%energy) THEN
243 466 : CALL get_qs_env(qs_env=qs_env, particle_set=particle_set)
244 466 : natom = SIZE(particle_set)
245 466 : CALL atprop_array_init(atprop%atecoul, natom)
246 : END IF
247 :
248 : ! 1/R contribution
249 12036 : do_ewald = dft_control%qs_control%dftb_control%do_ewald
250 12036 : IF (do_ewald) THEN
251 : ! Ewald sum
252 6510 : NULLIFY (ewald_env, ewald_pw)
253 : CALL get_qs_env(qs_env=qs_env, &
254 6510 : ewald_env=ewald_env, ewald_pw=ewald_pw)
255 6510 : CALL get_cell(cell=cell, periodic=periodic, deth=deth)
256 6510 : CALL ewald_env_get(ewald_env, alpha=alpha, ewald_type=ewald_type)
257 6510 : CALL get_qs_env(qs_env=qs_env, sab_tbe=n_list)
258 6510 : CALL tb_ewald_overlap(gmcharge, mcharge, alpha, n_list, virial, use_virial)
259 0 : SELECT CASE (ewald_type)
260 : CASE DEFAULT
261 0 : CPABORT("Invalid Ewald type")
262 : CASE (do_ewald_none)
263 0 : CPABORT("Not allowed with DFTB")
264 : CASE (do_ewald_ewald)
265 0 : CPABORT("Standard Ewald not implemented in DFTB")
266 : CASE (do_ewald_pme)
267 0 : CPABORT("PME not implemented in DFTB")
268 : CASE (do_ewald_spme)
269 : CALL tb_spme_evaluate(ewald_env, ewald_pw, particle_set, cell, &
270 6510 : gmcharge, mcharge, calculate_forces, virial, use_virial)
271 : END SELECT
272 : ELSE
273 : ! direct sum
274 : CALL get_qs_env(qs_env=qs_env, &
275 5526 : local_particles=local_particles)
276 17958 : DO ikind = 1, SIZE(local_particles%n_el)
277 26932 : DO ia = 1, local_particles%n_el(ikind)
278 8974 : iatom = local_particles%list(ikind)%array(ia)
279 31755 : DO jatom = 1, iatom - 1
280 41396 : rij = particle_set(iatom)%r - particle_set(jatom)%r
281 41396 : rij = pbc(rij, cell)
282 41396 : dr = SQRT(SUM(rij(:)**2))
283 10349 : gmcharge(iatom, 1) = gmcharge(iatom, 1) + mcharge(jatom)/dr
284 10349 : gmcharge(jatom, 1) = gmcharge(jatom, 1) + mcharge(iatom)/dr
285 20217 : DO i = 2, nmat
286 894 : gmcharge(iatom, i) = gmcharge(iatom, i) + rij(i - 1)*mcharge(jatom)/dr**3
287 11243 : gmcharge(jatom, i) = gmcharge(jatom, i) - rij(i - 1)*mcharge(iatom)/dr**3
288 : END DO
289 : END DO
290 : END DO
291 : END DO
292 5526 : CPASSERT(.NOT. use_virial)
293 : END IF
294 :
295 340104 : CALL para_env%sum(gmcharge(:, 1))
296 :
297 12036 : IF (do_ewald) THEN
298 : ! add self charge interaction and background charge contribution
299 152596 : gmcharge(:, 1) = gmcharge(:, 1) - 2._dp*alpha*oorootpi*mcharge(:)
300 7332 : IF (ANY(periodic(:) == 1)) THEN
301 151232 : gmcharge(:, 1) = gmcharge(:, 1) - pi/alpha**2/deth
302 : END IF
303 : END IF
304 :
305 176070 : energy%hartree = energy%hartree + 0.5_dp*SUM(mcharge(:)*gmcharge(:, 1))
306 12036 : IF (atprop%energy) THEN
307 : CALL get_qs_env(qs_env=qs_env, &
308 466 : local_particles=local_particles)
309 1526 : DO ikind = 1, SIZE(local_particles%n_el)
310 1060 : CALL get_qs_kind(qs_kind_set(ikind), dftb_parameter=dftb_kind)
311 1060 : CALL get_dftb_atom_param(dftb_kind, zeff=zeff)
312 18006 : DO ia = 1, local_particles%n_el(ikind)
313 16480 : iatom = local_particles%list(ikind)%array(ia)
314 : atprop%atecoul(iatom) = atprop%atecoul(iatom) + &
315 17540 : 0.5_dp*zeff*gmcharge(iatom, 1)
316 : END DO
317 : END DO
318 : END IF
319 :
320 12036 : IF (calculate_forces) THEN
321 : CALL get_atomic_kind_set(atomic_kind_set=atomic_kind_set, &
322 : kind_of=kind_of, &
323 616 : atom_of_kind=atom_of_kind)
324 :
325 14830 : gmcharge(:, 2) = gmcharge(:, 2)*mcharge(:)
326 14830 : gmcharge(:, 3) = gmcharge(:, 3)*mcharge(:)
327 14830 : gmcharge(:, 4) = gmcharge(:, 4)*mcharge(:)
328 14830 : DO iatom = 1, natom
329 14214 : ikind = kind_of(iatom)
330 14214 : atom_i = atom_of_kind(iatom)
331 14214 : force(ikind)%rho_elec(1, atom_i) = force(ikind)%rho_elec(1, atom_i) - gmcharge(iatom, 2)
332 14214 : force(ikind)%rho_elec(2, atom_i) = force(ikind)%rho_elec(2, atom_i) - gmcharge(iatom, 3)
333 14830 : force(ikind)%rho_elec(3, atom_i) = force(ikind)%rho_elec(3, atom_i) - gmcharge(iatom, 4)
334 : END DO
335 : END IF
336 :
337 12036 : do_gamma_stress = .FALSE.
338 12036 : IF (.NOT. just_energy .AND. use_virial) THEN
339 106 : IF (dft_control%nimages == 1) do_gamma_stress = .TRUE.
340 : END IF
341 :
342 12036 : IF (.NOT. just_energy) THEN
343 11764 : CALL get_qs_env(qs_env=qs_env, matrix_s_kp=matrix_s)
344 11764 : CALL qs_rho_get(rho, rho_ao_kp=matrix_p)
345 :
346 11764 : nimg = dft_control%nimages
347 11764 : NULLIFY (cell_to_index)
348 11764 : IF (nimg > 1) THEN
349 1988 : NULLIFY (kpoints)
350 1988 : CALL get_qs_env(qs_env=qs_env, kpoints=kpoints)
351 1988 : CALL get_kpoint_info(kpoint=kpoints, cell_to_index=cell_to_index)
352 : END IF
353 :
354 11764 : IF (calculate_forces .AND. SIZE(matrix_p, 1) == 2) THEN
355 328 : DO img = 1, nimg
356 : CALL dbcsr_add(matrix_p(1, img)%matrix, matrix_p(2, img)%matrix, &
357 328 : alpha_scalar=1.0_dp, beta_scalar=1.0_dp)
358 : END DO
359 : END IF
360 :
361 11764 : NULLIFY (sap_int)
362 11764 : IF (do_gamma_stress) THEN
363 : ! derivative overlap integral (non collapsed)
364 88 : CALL dftb_dsint_list(qs_env, sap_int)
365 : END IF
366 :
367 11764 : IF (nimg == 1) THEN
368 : ! no k-points; all matrices have been transformed to periodic bsf
369 9776 : CALL dbcsr_iterator_start(iter, matrix_s(1, 1)%matrix)
370 1735886 : DO WHILE (dbcsr_iterator_blocks_left(iter))
371 1726110 : CALL dbcsr_iterator_next_block(iter, irow, icol, sblock)
372 1726110 : gmij = 0.5_dp*(gmcharge(irow, 1) + gmcharge(icol, 1))
373 3453490 : DO is = 1, SIZE(ks_matrix, 1)
374 1727380 : NULLIFY (ksblock)
375 : CALL dbcsr_get_block_p(matrix=ks_matrix(is, 1)%matrix, &
376 1727380 : row=irow, col=icol, block=ksblock, found=found)
377 1727380 : CPASSERT(found)
378 26009094 : ksblock = ksblock - gmij*sblock
379 : END DO
380 1735886 : IF (calculate_forces) THEN
381 230483 : ikind = kind_of(irow)
382 230483 : atom_i = atom_of_kind(irow)
383 230483 : jkind = kind_of(icol)
384 230483 : atom_j = atom_of_kind(icol)
385 230483 : NULLIFY (pblock)
386 : CALL dbcsr_get_block_p(matrix=matrix_p(1, 1)%matrix, &
387 230483 : row=irow, col=icol, block=pblock, found=found)
388 230483 : CPASSERT(found)
389 921932 : DO i = 1, 3
390 691449 : NULLIFY (dsblock)
391 : CALL dbcsr_get_block_p(matrix=matrix_s(1 + i, 1)%matrix, &
392 691449 : row=irow, col=icol, block=dsblock, found=found)
393 691449 : CPASSERT(found)
394 4854186 : fi = -2.0_dp*gmij*SUM(pblock*dsblock)
395 691449 : force(ikind)%rho_elec(i, atom_i) = force(ikind)%rho_elec(i, atom_i) + fi
396 691449 : force(jkind)%rho_elec(i, atom_j) = force(jkind)%rho_elec(i, atom_j) - fi
397 1613381 : fij(i) = fi
398 : END DO
399 : END IF
400 : END DO
401 9776 : CALL dbcsr_iterator_stop(iter)
402 : !
403 9776 : IF (do_gamma_stress) THEN
404 264 : DO ikind = 1, nkind
405 616 : DO jkind = 1, nkind
406 352 : iac = ikind + nkind*(jkind - 1)
407 352 : IF (.NOT. ASSOCIATED(sap_int(iac)%alist)) CYCLE
408 8596 : DO ia = 1, sap_int(iac)%nalist
409 8076 : IF (.NOT. ASSOCIATED(sap_int(iac)%alist(ia)%clist)) CYCLE
410 8074 : iatom = sap_int(iac)%alist(ia)%aatom
411 177568 : DO ic = 1, sap_int(iac)%alist(ia)%nclist
412 169142 : jatom = sap_int(iac)%alist(ia)%clist(ic)%catom
413 676568 : rij = sap_int(iac)%alist(ia)%clist(ic)%rac
414 676568 : dr = SQRT(SUM(rij(:)**2))
415 177218 : IF (dr > 1.e-6_dp) THEN
416 165104 : dsint => sap_int(iac)%alist(ia)%clist(ic)%acint
417 165104 : gmij = 0.5_dp*(gmcharge(iatom, 1) + gmcharge(jatom, 1))
418 165104 : icol = MAX(iatom, jatom)
419 165104 : irow = MIN(iatom, jatom)
420 165104 : NULLIFY (pblock)
421 : CALL dbcsr_get_block_p(matrix=matrix_p(1, 1)%matrix, &
422 165104 : row=irow, col=icol, block=pblock, found=found)
423 165104 : CPASSERT(found)
424 660416 : DO i = 1, 3
425 660416 : IF (irow == iatom) THEN
426 1721034 : fij(i) = -2.0_dp*gmij*SUM(pblock*dsint(:, :, i))
427 : ELSE
428 1730961 : fij(i) = -2.0_dp*gmij*SUM(TRANSPOSE(pblock)*dsint(:, :, i))
429 : END IF
430 : END DO
431 165104 : fi = 1.0_dp
432 165104 : IF (iatom == jatom) fi = 0.5_dp
433 165104 : CALL virial_pair_force(virial%pv_virial, fi, fij, rij)
434 : END IF
435 : END DO
436 : END DO
437 : END DO
438 : END DO
439 : END IF
440 : ELSE
441 1988 : NULLIFY (n_list)
442 1988 : CALL get_qs_env(qs_env=qs_env, sab_orb=n_list)
443 1988 : CALL neighbor_list_iterator_create(nl_iterator, n_list)
444 245594 : DO WHILE (neighbor_list_iterate(nl_iterator) == 0)
445 : CALL get_iterator_info(nl_iterator, ikind=ikind, jkind=jkind, &
446 243606 : iatom=iatom, jatom=jatom, r=rij, cell=cellind)
447 :
448 243606 : icol = MAX(iatom, jatom)
449 243606 : irow = MIN(iatom, jatom)
450 243606 : ic = cell_to_index(cellind(1), cellind(2), cellind(3))
451 243606 : CPASSERT(ic > 0)
452 :
453 243606 : gmij = 0.5_dp*(gmcharge(iatom, 1) + gmcharge(jatom, 1))
454 :
455 243606 : NULLIFY (sblock)
456 : CALL dbcsr_get_block_p(matrix=matrix_s(1, ic)%matrix, &
457 243606 : row=irow, col=icol, block=sblock, found=found)
458 243606 : CPASSERT(found)
459 487212 : DO is = 1, SIZE(ks_matrix, 1)
460 243606 : NULLIFY (ksblock)
461 : CALL dbcsr_get_block_p(matrix=ks_matrix(is, ic)%matrix, &
462 243606 : row=irow, col=icol, block=ksblock, found=found)
463 243606 : CPASSERT(found)
464 4849788 : ksblock = ksblock - gmij*sblock
465 : END DO
466 :
467 245594 : IF (calculate_forces) THEN
468 4182 : ikind = kind_of(iatom)
469 4182 : atom_i = atom_of_kind(iatom)
470 4182 : jkind = kind_of(jatom)
471 4182 : atom_j = atom_of_kind(jatom)
472 4182 : IF (irow == jatom) gmij = -gmij
473 4182 : NULLIFY (pblock)
474 : CALL dbcsr_get_block_p(matrix=matrix_p(1, ic)%matrix, &
475 4182 : row=irow, col=icol, block=pblock, found=found)
476 4182 : CPASSERT(found)
477 16728 : DO i = 1, 3
478 12546 : NULLIFY (dsblock)
479 : CALL dbcsr_get_block_p(matrix=matrix_s(1 + i, ic)%matrix, &
480 12546 : row=irow, col=icol, block=dsblock, found=found)
481 12546 : CPASSERT(found)
482 227889 : fi = -2.0_dp*gmij*SUM(pblock*dsblock)
483 12546 : force(ikind)%rho_elec(i, atom_i) = force(ikind)%rho_elec(i, atom_i) + fi
484 12546 : force(jkind)%rho_elec(i, atom_j) = force(jkind)%rho_elec(i, atom_j) - fi
485 29274 : fij(i) = fi
486 : END DO
487 4182 : IF (use_virial) THEN
488 4182 : fi = 1.0_dp
489 4182 : IF (iatom == jatom) fi = 0.5_dp
490 4182 : CALL virial_pair_force(virial%pv_virial, fi, fij, rij)
491 : END IF
492 : END IF
493 : END DO
494 1988 : CALL neighbor_list_iterator_release(nl_iterator)
495 : END IF
496 :
497 11764 : IF (calculate_forces .AND. SIZE(matrix_p, 1) == 2) THEN
498 328 : DO img = 1, nimg
499 : CALL dbcsr_add(matrix_p(1, img)%matrix, matrix_p(2, img)%matrix, &
500 328 : alpha_scalar=1.0_dp, beta_scalar=-1.0_dp)
501 : END DO
502 : END IF
503 : END IF
504 :
505 12036 : IF (dft_control%qs_control%dftb_control%dftb3_diagonal) THEN
506 2884 : CALL get_qs_env(qs_env, nkind=nkind)
507 11536 : ALLOCATE (zeffk(nkind), xgamma(nkind))
508 8552 : DO ikind = 1, nkind
509 5668 : CALL get_qs_kind(qs_kind_set(ikind), dftb_parameter=dftb_kind)
510 8552 : CALL get_dftb_atom_param(dftb_kind, dudq=xgamma(ikind), zeff=zeffk(ikind))
511 : END DO
512 : ! Diagonal 3rd order correction (DFTB3)
513 : CALL build_dftb3_diagonal(qs_env, ks_matrix, rho, mcharge, energy, xgamma, zeffk, &
514 2884 : sap_int, calculate_forces, just_energy)
515 2884 : DEALLOCATE (zeffk, xgamma)
516 : END IF
517 :
518 : ! QMMM
519 12036 : IF (qs_env%qmmm .AND. qs_env%qmmm_periodic) THEN
520 : CALL build_tb_coulomb_qmqm(qs_env, ks_matrix, rho, mcharge, energy, &
521 1626 : calculate_forces, just_energy)
522 : END IF
523 :
524 12036 : IF (do_gamma_stress) THEN
525 88 : CALL release_sap_int(sap_int)
526 : END IF
527 :
528 12036 : DEALLOCATE (gmcharge)
529 :
530 12036 : CALL timestop(handle)
531 :
532 24072 : END SUBROUTINE build_dftb_coulomb
533 :
534 : ! **************************************************************************************************
535 : !> \brief Computes the short-range gamma parameter from exact Coulomb
536 : !> interaction of normalized exp(-a*r) charge distribution - 1/r
537 : !> \param r ...
538 : !> \param ga ...
539 : !> \param gb ...
540 : !> \param hb_para ...
541 : !> \return ...
542 : !> \par Literature
543 : !> Elstner et al, PRB 58 (1998) 7260
544 : !> \par History
545 : !> 10.2008 Axel Kohlmeyer - adding sr_damp
546 : !> 08.2014 JGH - adding flexible exponent for damping
547 : !> \version 1.1
548 : ! **************************************************************************************************
549 2981055 : FUNCTION gamma_rab_sr(r, ga, gb, hb_para) RESULT(gamma)
550 : REAL(dp), INTENT(in) :: r, ga, gb, hb_para
551 : REAL(dp) :: gamma
552 :
553 : REAL(dp) :: a, b, fac, g_sum
554 :
555 2981055 : gamma = 0.0_dp
556 2981055 : a = 3.2_dp*ga ! 3.2 = 16/5 in Eq. 18 and ff.
557 2981055 : b = 3.2_dp*gb
558 2981055 : g_sum = a + b
559 2981055 : IF (g_sum < tol_gamma) RETURN ! hardness screening
560 2981055 : IF (r < rtiny) THEN ! This is for short distances but non-onsite terms
561 : ! This gives also correct diagonal elements (a=b, r=0)
562 82017 : gamma = 0.5_dp*(a*b/g_sum + (a*b)**2/g_sum**3)
563 82017 : RETURN
564 : END IF
565 : !
566 : ! distinguish two cases: Gamma's are very close, e.g. for the same atom type,
567 : ! and Gamma's are different
568 : !
569 2899038 : IF (ABS(a - b) < rtiny) THEN
570 1633213 : fac = 1.6_dp*r*a*b/g_sum*(1.0_dp + a*b/g_sum**2)
571 1633213 : gamma = -(48.0_dp + 33._dp*fac + (9.0_dp + fac)*fac**2)*EXP(-fac)/(48._dp*r)
572 : ELSE
573 : gamma = -EXP(-a*r)*(0.5_dp*a*b**4/(a**2 - b**2)**2 - &
574 : (b**6 - 3._dp*a**2*b**4)/(r*(a**2 - b**2)**3)) - & ! a-> b
575 : EXP(-b*r)*(0.5_dp*b*a**4/(b**2 - a**2)**2 - &
576 1265825 : (a**6 - 3._dp*b**2*a**4)/(r*(b**2 - a**2)**3)) ! b-> a
577 : END IF
578 : !
579 : ! damping function for better short range hydrogen bonds.
580 : ! functional form from Hu H. et al., J. Phys. Chem. A 2007, 111, 5685-5691
581 : ! according to Elstner M, Theor. Chem. Acc. 2006, 116, 316-325,
582 : ! this should only be applied to a-b pairs involving hydrogen.
583 2899038 : IF (hb_para > 0.0_dp) THEN
584 496986 : gamma = gamma*EXP(-(0.5_dp*(ga + gb))**hb_para*r*r)
585 : END IF
586 : END FUNCTION gamma_rab_sr
587 :
588 : ! **************************************************************************************************
589 : !> \brief ...
590 : !> \param qs_env ...
591 : !> \param sap_int ...
592 : ! **************************************************************************************************
593 88 : SUBROUTINE dftb_dsint_list(qs_env, sap_int)
594 :
595 : TYPE(qs_environment_type), POINTER :: qs_env
596 : TYPE(sap_int_type), DIMENSION(:), POINTER :: sap_int
597 :
598 : CHARACTER(LEN=*), PARAMETER :: routineN = 'dftb_dsint_list'
599 :
600 : INTEGER :: handle, i, iac, iatom, ikind, ilist, jatom, jkind, jneighbor, llm, lmaxi, lmaxj, &
601 : n1, n2, natorb_a, natorb_b, ngrd, ngrdcut, nkind, nlist, nneighbor
602 : INTEGER, DIMENSION(3) :: cell
603 : LOGICAL :: defined
604 : REAL(KIND=dp) :: ddr, dgrd, dr
605 : REAL(KIND=dp), DIMENSION(3) :: drij, rij
606 88 : REAL(KIND=dp), DIMENSION(:, :), POINTER :: dsblock, dsblockm, smatij, smatji
607 : TYPE(clist_type), POINTER :: clist
608 : TYPE(dft_control_type), POINTER :: dft_control
609 : TYPE(dftb_control_type), POINTER :: dftb_control
610 : TYPE(neighbor_list_iterator_p_type), &
611 88 : DIMENSION(:), POINTER :: nl_iterator
612 : TYPE(neighbor_list_set_p_type), DIMENSION(:), &
613 88 : POINTER :: sab_orb
614 : TYPE(qs_dftb_atom_type), POINTER :: dftb_kind_a, dftb_kind_b
615 : TYPE(qs_dftb_pairpot_type), DIMENSION(:, :), &
616 88 : POINTER :: dftb_potential
617 : TYPE(qs_dftb_pairpot_type), POINTER :: dftb_param_ij, dftb_param_ji
618 88 : TYPE(qs_kind_type), DIMENSION(:), POINTER :: qs_kind_set
619 :
620 88 : CALL timeset(routineN, handle)
621 :
622 88 : CALL get_qs_env(qs_env=qs_env, nkind=nkind)
623 88 : CPASSERT(.NOT. ASSOCIATED(sap_int))
624 616 : ALLOCATE (sap_int(nkind*nkind))
625 440 : DO i = 1, nkind*nkind
626 352 : NULLIFY (sap_int(i)%alist, sap_int(i)%asort, sap_int(i)%aindex)
627 440 : sap_int(i)%nalist = 0
628 : END DO
629 :
630 : CALL get_qs_env(qs_env=qs_env, &
631 : qs_kind_set=qs_kind_set, &
632 : dft_control=dft_control, &
633 88 : sab_orb=sab_orb)
634 :
635 88 : dftb_control => dft_control%qs_control%dftb_control
636 :
637 88 : NULLIFY (dftb_potential)
638 : CALL get_qs_env(qs_env=qs_env, &
639 88 : dftb_potential=dftb_potential)
640 :
641 : ! loop over all atom pairs with a non-zero overlap (sab_orb)
642 88 : CALL neighbor_list_iterator_create(nl_iterator, sab_orb)
643 169230 : DO WHILE (neighbor_list_iterate(nl_iterator) == 0)
644 : CALL get_iterator_info(nl_iterator, ikind=ikind, jkind=jkind, iatom=iatom, &
645 : jatom=jatom, nlist=nlist, ilist=ilist, nnode=nneighbor, &
646 169142 : inode=jneighbor, cell=cell, r=rij)
647 169142 : iac = ikind + nkind*(jkind - 1)
648 : !
649 169142 : CALL get_qs_kind(qs_kind_set(ikind), dftb_parameter=dftb_kind_a)
650 : CALL get_dftb_atom_param(dftb_kind_a, &
651 169142 : defined=defined, lmax=lmaxi, natorb=natorb_a)
652 169142 : IF (.NOT. defined .OR. natorb_a < 1) CYCLE
653 169142 : CALL get_qs_kind(qs_kind_set(jkind), dftb_parameter=dftb_kind_b)
654 : CALL get_dftb_atom_param(dftb_kind_b, &
655 169142 : defined=defined, lmax=lmaxj, natorb=natorb_b)
656 169142 : IF (.NOT. defined .OR. natorb_b < 1) CYCLE
657 :
658 676568 : dr = SQRT(SUM(rij(:)**2))
659 :
660 : ! integral list
661 169142 : IF (.NOT. ASSOCIATED(sap_int(iac)%alist)) THEN
662 344 : sap_int(iac)%a_kind = ikind
663 344 : sap_int(iac)%p_kind = jkind
664 344 : sap_int(iac)%nalist = nlist
665 9108 : ALLOCATE (sap_int(iac)%alist(nlist))
666 8420 : DO i = 1, nlist
667 8076 : NULLIFY (sap_int(iac)%alist(i)%clist)
668 8076 : sap_int(iac)%alist(i)%aatom = 0
669 8420 : sap_int(iac)%alist(i)%nclist = 0
670 : END DO
671 : END IF
672 169142 : IF (.NOT. ASSOCIATED(sap_int(iac)%alist(ilist)%clist)) THEN
673 8074 : sap_int(iac)%alist(ilist)%aatom = iatom
674 8074 : sap_int(iac)%alist(ilist)%nclist = nneighbor
675 241808 : ALLOCATE (sap_int(iac)%alist(ilist)%clist(nneighbor))
676 177216 : DO i = 1, nneighbor
677 177216 : sap_int(iac)%alist(ilist)%clist(i)%catom = 0
678 : END DO
679 : END IF
680 169142 : clist => sap_int(iac)%alist(ilist)%clist(jneighbor)
681 169142 : clist%catom = jatom
682 676568 : clist%cell = cell
683 676568 : clist%rac = rij
684 845710 : ALLOCATE (clist%acint(natorb_a, natorb_b, 3))
685 169142 : NULLIFY (clist%achint)
686 3730163 : clist%acint = 0._dp
687 169142 : clist%nsgf_cnt = 0
688 169142 : NULLIFY (clist%sgf_list)
689 :
690 : ! retrieve information on S matrix
691 169142 : dftb_param_ij => dftb_potential(ikind, jkind)
692 169142 : dftb_param_ji => dftb_potential(jkind, ikind)
693 : ! assume table size and type is symmetric
694 169142 : ngrd = dftb_param_ij%ngrd
695 169142 : ngrdcut = dftb_param_ij%ngrdcut
696 169142 : dgrd = dftb_param_ij%dgrd
697 169142 : ddr = dgrd*0.1_dp
698 169142 : CPASSERT(dftb_param_ij%llm == dftb_param_ji%llm)
699 169142 : llm = dftb_param_ij%llm
700 169142 : smatij => dftb_param_ij%smat
701 169142 : smatji => dftb_param_ji%smat
702 :
703 507514 : IF (NINT(dr/dgrd) <= ngrdcut) THEN
704 168768 : IF (iatom == jatom .AND. dr < 0.001_dp) THEN
705 : ! diagonal block
706 : ELSE
707 : ! off-diagonal block
708 164730 : n1 = natorb_a
709 164730 : n2 = natorb_b
710 988380 : ALLOCATE (dsblock(n1, n2), dsblockm(n1, n2))
711 658920 : DO i = 1, 3
712 3443355 : dsblock = 0._dp
713 3443355 : dsblockm = 0.0_dp
714 494190 : drij = rij
715 :
716 494190 : drij(i) = rij(i) - ddr
717 : CALL compute_block_sk(dsblockm, smatij, smatji, drij, ngrd, ngrdcut, dgrd, &
718 494190 : llm, lmaxi, lmaxj, iatom, iatom)
719 :
720 494190 : drij(i) = rij(i) + ddr
721 : CALL compute_block_sk(dsblock, smatij, smatji, drij, ngrd, ngrdcut, dgrd, &
722 494190 : llm, lmaxi, lmaxj, iatom, iatom)
723 :
724 6392520 : dsblock = dsblock - dsblockm
725 3443355 : dsblock = dsblock/(2.0_dp*ddr)
726 :
727 6557250 : clist%acint(1:n1, 1:n2, i) = -dsblock(1:n1, 1:n2)
728 : END DO
729 164730 : DEALLOCATE (dsblock, dsblockm)
730 : END IF
731 : END IF
732 :
733 : END DO
734 88 : CALL neighbor_list_iterator_release(nl_iterator)
735 :
736 88 : CALL timestop(handle)
737 :
738 88 : END SUBROUTINE dftb_dsint_list
739 :
740 : END MODULE qs_dftb_coulomb
741 :
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