Line data Source code
1 : !--------------------------------------------------------------------------------------------------!
2 : ! CP2K: A general program to perform molecular dynamics simulations !
3 : ! Copyright 2000-2026 CP2K developers group <https://cp2k.org> !
4 : ! !
5 : ! SPDX-License-Identifier: GPL-2.0-or-later !
6 : !--------------------------------------------------------------------------------------------------!
7 :
8 : ! **************************************************************************************************
9 : !> \brief Set occupation of molecular orbitals
10 : !> \par History
11 : !> - set_mo_occupation subroutines moved from qs_mo_types (11.12.2014 MI)
12 : !> \author MI
13 : ! **************************************************************************************************
14 :
15 : MODULE qs_mo_occupation
16 :
17 : USE cp_control_types, ONLY: hairy_probes_type
18 : USE cp_log_handling, ONLY: cp_to_string
19 : USE hairy_probes, ONLY: probe_occupancy
20 : USE input_constants, ONLY: smear_energy_window,&
21 : smear_fermi_dirac,&
22 : smear_gaussian,&
23 : smear_list,&
24 : smear_mp,&
25 : smear_mv
26 : USE kahan_sum, ONLY: accurate_sum
27 : USE kinds, ONLY: dp
28 : USE qs_mo_types, ONLY: get_mo_set,&
29 : has_uniform_occupation,&
30 : mo_set_type,&
31 : set_mo_set
32 : USE scf_control_types, ONLY: gce_type,&
33 : smear_type
34 : USE smearing_utils, ONLY: SmearFixed,&
35 : SmearFixedDerivMV,&
36 : SmearOcc
37 : USE util, ONLY: sort
38 : USE xas_env_types, ONLY: get_xas_env,&
39 : xas_environment_type
40 : #include "./base/base_uses.f90"
41 :
42 : IMPLICIT NONE
43 :
44 : PRIVATE
45 :
46 : CHARACTER(len=*), PARAMETER, PRIVATE :: moduleN = 'qs_mo_occupation'
47 :
48 : PUBLIC :: set_mo_occupation
49 :
50 : INTERFACE set_mo_occupation
51 : MODULE PROCEDURE set_mo_occupation_1, set_mo_occupation_2
52 : END INTERFACE
53 :
54 : CONTAINS
55 :
56 : ! **************************************************************************************************
57 : !> \brief Occupation for smeared spin polarized electronic structures
58 : !> with relaxed multiplicity
59 : !>
60 : !> \param mo_array ...
61 : !> \param smear ...
62 : !> \param gce ...
63 : !> \date 10.03.2011 (MI)
64 : !> \author MI
65 : !> \version 1.0
66 : ! **************************************************************************************************
67 2680 : SUBROUTINE set_mo_occupation_3(mo_array, smear, gce)
68 :
69 : TYPE(mo_set_type), DIMENSION(2), INTENT(INOUT) :: mo_array
70 : TYPE(smear_type) :: smear
71 : TYPE(gce_type), OPTIONAL, POINTER :: gce
72 :
73 : CHARACTER(LEN=*), PARAMETER :: routineN = 'set_mo_occupation_3'
74 :
75 : CHARACTER(LEN=32) :: method_label
76 : INTEGER :: all_nmo, handle, homo_a, homo_b, i, &
77 : lfomo_a, lfomo_b, nmo_a, nmo_b, &
78 : xas_estate
79 2680 : INTEGER, ALLOCATABLE, DIMENSION(:) :: all_index
80 : LOGICAL :: do_gce, is_large
81 : REAL(KIND=dp) :: all_nelec, kTS, mu, nelec_a, nelec_b, &
82 : occ_estate, smear_width
83 : REAL(KIND=dp), ALLOCATABLE, DIMENSION(:) :: all_eigval, all_occ
84 2680 : REAL(KIND=dp), DIMENSION(:), POINTER :: eigval_a, eigval_b, occ_a, occ_b
85 :
86 2680 : CALL timeset(routineN, handle)
87 :
88 2680 : NULLIFY (eigval_a, eigval_b, occ_a, occ_b)
89 : CALL get_mo_set(mo_set=mo_array(1), nmo=nmo_a, eigenvalues=eigval_a, &
90 2680 : occupation_numbers=occ_a)
91 : CALL get_mo_set(mo_set=mo_array(2), nmo=nmo_b, eigenvalues=eigval_b, &
92 2680 : occupation_numbers=occ_b)
93 2680 : all_nmo = nmo_a + nmo_b
94 8040 : ALLOCATE (all_eigval(all_nmo))
95 5360 : ALLOCATE (all_occ(all_nmo))
96 8040 : ALLOCATE (all_index(all_nmo))
97 :
98 37540 : all_eigval(1:nmo_a) = eigval_a(1:nmo_a)
99 35562 : all_eigval(nmo_a + 1:all_nmo) = eigval_b(1:nmo_b)
100 :
101 2680 : CALL sort(all_eigval, all_nmo, all_index)
102 :
103 2680 : IF (PRESENT(gce)) THEN
104 172 : do_gce = gce%do_gce
105 : ELSE
106 : do_gce = .FALSE.
107 : END IF
108 :
109 5088 : SELECT CASE (smear%method)
110 : CASE (smear_fermi_dirac)
111 2408 : smear_width = smear%electronic_temperature
112 2408 : method_label = "Fermi-Dirac"
113 : CASE (smear_gaussian)
114 164 : smear_width = smear%smearing_width
115 164 : method_label = "Gaussian"
116 : CASE (smear_mp)
117 0 : smear_width = smear%smearing_width
118 0 : method_label = "Methfessel-Paxton"
119 : CASE (smear_mv)
120 108 : smear_width = smear%smearing_width
121 108 : method_label = "Marzari-Vanderbilt"
122 : CASE DEFAULT
123 2680 : CPABORT("set_mo_occupation_3: unsupported smearing method")
124 : END SELECT
125 :
126 2680 : IF (.NOT. do_gce) THEN
127 2508 : xas_estate = -1
128 2508 : occ_estate = 0.0_dp
129 :
130 : nelec_a = 0.0_dp
131 : nelec_b = 0.0_dp
132 : all_nelec = 0.0_dp
133 2508 : nelec_a = accurate_sum(occ_a(:))
134 2508 : nelec_b = accurate_sum(occ_b(:))
135 2508 : all_nelec = nelec_a + nelec_b
136 :
137 63714 : DO i = 1, all_nmo
138 63714 : IF (all_index(i) <= nmo_a) THEN
139 31592 : all_occ(i) = occ_a(all_index(i))
140 : ELSE
141 29614 : all_occ(i) = occ_b(all_index(i) - nmo_a)
142 : END IF
143 : END DO
144 :
145 : CALL SmearFixed(all_occ, mu, kTS, all_eigval, all_nelec, &
146 2508 : smear_width, 1._dp, smear%method, xas_estate, occ_estate)
147 : ELSE
148 172 : gce%prev_workfunction = gce%ref_esp - mo_array(1)%mu
149 172 : mu = gce%ref_esp - ((1.0_dp - gce%mixing_coef)*gce%prev_workfunction + gce%mixing_coef*gce%target_workfunction)
150 172 : CALL SmearOcc(all_occ, all_nelec, kTS, all_eigval, mu, smear_width, 1._dp, smear%method)
151 : END IF
152 :
153 2680 : is_large = ABS(all_occ(1) - 1.0_dp) > smear%eps_fermi_dirac
154 : ! this is not a real problem, but the smearing width might be a bit large
155 2680 : CPWARN_IF(is_large, TRIM(method_label)//" smearing includes the first MO")
156 :
157 2680 : is_large = ABS(all_occ(all_nmo)) > smear%eps_fermi_dirac
158 2680 : IF (is_large) THEN
159 : CALL cp_warn(__LOCATION__, &
160 : TRIM(method_label)//" smearing includes the last MO => "// &
161 20 : "Add more MOs for proper smearing.")
162 : END IF
163 2680 : IF (.NOT. do_gce) THEN
164 : ! check that the total electron count is accurate
165 2508 : is_large = (ABS(all_nelec - accurate_sum(all_occ(:))) > smear%eps_fermi_dirac*all_nelec)
166 2508 : CPWARN_IF(is_large, "Total number of electrons is not accurate")
167 : END IF
168 :
169 70422 : DO i = 1, all_nmo
170 70422 : IF (all_index(i) <= nmo_a) THEN
171 34860 : occ_a(all_index(i)) = all_occ(i)
172 34860 : eigval_a(all_index(i)) = all_eigval(i)
173 : ELSE
174 32882 : occ_b(all_index(i) - nmo_a) = all_occ(i)
175 32882 : eigval_b(all_index(i) - nmo_a) = all_eigval(i)
176 : END IF
177 : END DO
178 :
179 2680 : nelec_a = accurate_sum(occ_a(:))
180 2680 : nelec_b = accurate_sum(occ_b(:))
181 :
182 2680 : lfomo_a = nmo_a + 1
183 2680 : lfomo_b = nmo_b + 1
184 : homo_a = 0
185 : homo_b = 0
186 :
187 22286 : DO i = 1, nmo_a
188 22286 : IF (occ_a(i) < 1.0_dp) THEN
189 2680 : lfomo_a = i
190 2680 : EXIT
191 : END IF
192 : END DO
193 21914 : DO i = 1, nmo_b
194 21914 : IF (occ_b(i) < 1.0_dp) THEN
195 2680 : lfomo_b = i
196 2680 : EXIT
197 : END IF
198 : END DO
199 2680 : homo_a = lfomo_a - 1
200 14304 : DO i = nmo_a, lfomo_a, -1
201 14304 : IF (ABS(occ_a(i)) > smear%eps_fermi_dirac) THEN
202 1980 : homo_a = i
203 1980 : EXIT
204 : END IF
205 : END DO
206 2680 : homo_b = lfomo_b - 1
207 14198 : DO i = nmo_b, lfomo_b, -1
208 14198 : IF (ABS(occ_b(i)) > smear%eps_fermi_dirac) THEN
209 1224 : homo_b = i
210 1224 : EXIT
211 : END IF
212 : END DO
213 :
214 : CALL set_mo_set(mo_set=mo_array(1), kTS=kTS/2.0_dp, mu=mu, n_el_f=nelec_a, &
215 2680 : lfomo=lfomo_a, homo=homo_a, uniform_occupation=.FALSE.)
216 : CALL set_mo_set(mo_set=mo_array(2), kTS=kTS/2.0_dp, mu=mu, n_el_f=nelec_b, &
217 2680 : lfomo=lfomo_b, homo=homo_b, uniform_occupation=.FALSE.)
218 :
219 2680 : CALL timestop(handle)
220 :
221 5360 : END SUBROUTINE set_mo_occupation_3
222 :
223 : ! **************************************************************************************************
224 : !> \brief Prepare an occupation of alpha and beta MOs following an Aufbau
225 : !> principle, i.e. allowing a change in multiplicity.
226 : !> \param mo_array ...
227 : !> \param smear ...
228 : !> \param eval_deriv ...
229 : !> \param tot_zeff_corr ...
230 : !> \param probe ...
231 : !> \param gce ...
232 : !> \date 25.01.2010 (MK)
233 : !> \par History
234 : !> 10.2019 Added functionality to adjust mo occupation if the core
235 : !> charges are changed via CORE_CORRECTION during surface dipole
236 : !> calculation. Total number of electrons matches the total core
237 : !> charges if tot_zeff_corr is non-zero. Not yet implemented for
238 : !> OT type method. [Soumya Ghosh]
239 : !> \author Matthias Krack (MK)
240 : !> \version 1.0
241 : ! **************************************************************************************************
242 121003 : SUBROUTINE set_mo_occupation_2(mo_array, smear, eval_deriv, tot_zeff_corr, probe, gce)
243 :
244 : TYPE(mo_set_type), DIMENSION(:), INTENT(INOUT) :: mo_array
245 : TYPE(smear_type) :: smear
246 : REAL(KIND=dp), DIMENSION(:), OPTIONAL, POINTER :: eval_deriv
247 : REAL(KIND=dp), OPTIONAL :: tot_zeff_corr
248 : TYPE(hairy_probes_type), DIMENSION(:), OPTIONAL, &
249 : POINTER :: probe
250 : TYPE(gce_type), OPTIONAL, POINTER :: gce
251 :
252 : CHARACTER(LEN=*), PARAMETER :: routineN = 'set_mo_occupation_2'
253 :
254 : INTEGER :: handle, i, lumo_a, lumo_b, &
255 : multiplicity_new, multiplicity_old, &
256 : nelec
257 : REAL(KIND=dp) :: nelec_f, threshold
258 121003 : REAL(KIND=dp), DIMENSION(:), POINTER :: eigval_a, eigval_b
259 :
260 121003 : CALL timeset(routineN, handle)
261 :
262 : ! Fall back for the case that we have only one MO set
263 121003 : IF (SIZE(mo_array) == 1) THEN
264 102143 : IF (PRESENT(probe)) THEN
265 14 : CALL set_mo_occupation_1(mo_array(1), smear=smear, probe=probe)
266 102129 : ELSE IF (PRESENT(eval_deriv)) THEN
267 : ! Change of MO occupancy to account for CORE_CORRECTION is not yet implemented
268 0 : IF (PRESENT(gce)) THEN
269 0 : CALL set_mo_occupation_1(mo_array(1), smear=smear, eval_deriv=eval_deriv, gce=gce)
270 : ELSE
271 0 : CALL set_mo_occupation_1(mo_array(1), smear=smear, eval_deriv=eval_deriv)
272 : END IF
273 : ELSE
274 102129 : IF (PRESENT(tot_zeff_corr)) THEN
275 20 : CALL set_mo_occupation_1(mo_array(1), smear=smear, tot_zeff_corr=tot_zeff_corr)
276 : ELSE
277 102109 : IF (PRESENT(gce)) THEN
278 196 : CALL set_mo_occupation_1(mo_array(1), smear=smear, gce=gce)
279 : ELSE
280 101913 : CALL set_mo_occupation_1(mo_array(1), smear=smear)
281 : END IF
282 : END IF
283 : END IF
284 102143 : CALL timestop(handle)
285 : RETURN
286 : END IF
287 :
288 18860 : IF (PRESENT(probe)) THEN
289 0 : CALL set_mo_occupation_1(mo_array(1), smear=smear, probe=probe)
290 0 : CALL set_mo_occupation_1(mo_array(2), smear=smear, probe=probe)
291 : END IF
292 :
293 18860 : IF (smear%do_smear) THEN
294 4596 : IF (smear%fixed_mag_mom < 0.0_dp) THEN
295 3034 : IF (PRESENT(tot_zeff_corr)) THEN
296 : CALL cp_warn(__LOCATION__, &
297 : "CORE_CORRECTION /= 0.0 might cause the cell to charge up "// &
298 : "that will lead to application of different background "// &
299 : "correction compared to the reference system. "// &
300 : "Use FIXED_MAGNETIC_MOMENT >= 0.0 if using SMEAR keyword "// &
301 0 : "to correct the electron density")
302 : END IF
303 3034 : IF (smear%fixed_mag_mom /= -1.0_dp) THEN
304 2680 : CPASSERT(.NOT. (PRESENT(eval_deriv)))
305 2680 : CALL set_mo_occupation_3(mo_array, smear=smear, gce=gce)
306 2680 : CALL timestop(handle)
307 2680 : RETURN
308 : END IF
309 : ELSE
310 1562 : nelec_f = mo_array(1)%n_el_f + mo_array(2)%n_el_f
311 1562 : IF (ABS((mo_array(1)%n_el_f - mo_array(2)%n_el_f) - smear%fixed_mag_mom) > smear%eps_fermi_dirac*nelec_f) THEN
312 2 : mo_array(1)%n_el_f = nelec_f/2.0_dp + smear%fixed_mag_mom/2.0_dp
313 2 : mo_array(2)%n_el_f = nelec_f/2.0_dp - smear%fixed_mag_mom/2.0_dp
314 : END IF
315 1562 : CPASSERT(.NOT. (PRESENT(eval_deriv)))
316 1562 : IF (PRESENT(tot_zeff_corr)) THEN
317 20 : CALL set_mo_occupation_1(mo_array(1), smear=smear, tot_zeff_corr=tot_zeff_corr)
318 20 : CALL set_mo_occupation_1(mo_array(2), smear=smear, tot_zeff_corr=tot_zeff_corr)
319 : ELSE
320 1542 : CALL set_mo_occupation_1(mo_array(1), smear=smear)
321 1542 : CALL set_mo_occupation_1(mo_array(2), smear=smear)
322 : END IF
323 : END IF
324 : END IF
325 :
326 16180 : IF (.NOT. ((mo_array(1)%flexible_electron_count > 0.0_dp) .AND. &
327 : (mo_array(2)%flexible_electron_count > 0.0_dp))) THEN
328 15994 : IF (PRESENT(probe)) THEN
329 0 : CALL set_mo_occupation_1(mo_array(1), smear=smear, probe=probe)
330 0 : CALL set_mo_occupation_1(mo_array(2), smear=smear, probe=probe)
331 15994 : ELSE IF (PRESENT(eval_deriv)) THEN
332 0 : CALL set_mo_occupation_1(mo_array(1), smear=smear, eval_deriv=eval_deriv)
333 0 : CALL set_mo_occupation_1(mo_array(2), smear=smear, eval_deriv=eval_deriv)
334 : ELSE
335 15994 : IF (PRESENT(tot_zeff_corr)) THEN
336 20 : CALL set_mo_occupation_1(mo_array(1), smear=smear, tot_zeff_corr=tot_zeff_corr)
337 20 : CALL set_mo_occupation_1(mo_array(2), smear=smear, tot_zeff_corr=tot_zeff_corr)
338 : ELSE
339 15974 : CALL set_mo_occupation_1(mo_array(1), smear=smear)
340 15974 : CALL set_mo_occupation_1(mo_array(2), smear=smear)
341 : END IF
342 : END IF
343 15994 : CALL timestop(handle)
344 15994 : RETURN
345 : END IF
346 :
347 186 : nelec = mo_array(1)%nelectron + mo_array(2)%nelectron
348 :
349 186 : multiplicity_old = mo_array(1)%nelectron - mo_array(2)%nelectron + 1
350 :
351 186 : IF (mo_array(1)%nelectron >= mo_array(1)%nmo) THEN
352 : CALL cp_warn(__LOCATION__, &
353 : "All alpha MOs are occupied. Add more alpha MOs to "// &
354 0 : "allow for a higher multiplicity")
355 : END IF
356 186 : IF ((mo_array(2)%nelectron >= mo_array(2)%nmo) .AND. (mo_array(2)%nelectron /= mo_array(1)%nelectron)) THEN
357 : CALL cp_warn(__LOCATION__, "All beta MOs are occupied. Add more beta MOs to "// &
358 0 : "allow for a lower multiplicity")
359 : END IF
360 :
361 186 : eigval_a => mo_array(1)%eigenvalues
362 186 : eigval_b => mo_array(2)%eigenvalues
363 :
364 186 : lumo_a = 1
365 186 : lumo_b = 1
366 :
367 : ! Apply Aufbau principle
368 2306 : DO i = 1, nelec
369 : ! Threshold is needed to ensure a preference for alpha occupation in the case
370 : ! of degeneracy
371 2120 : threshold = MAX(mo_array(1)%flexible_electron_count, mo_array(2)%flexible_electron_count)
372 2120 : IF ((eigval_a(lumo_a) - threshold) < eigval_b(lumo_b)) THEN
373 1212 : lumo_a = lumo_a + 1
374 : ELSE
375 908 : lumo_b = lumo_b + 1
376 : END IF
377 2120 : IF (lumo_a > mo_array(1)%nmo) THEN
378 0 : IF (i /= nelec) THEN
379 : CALL cp_warn(__LOCATION__, &
380 : "All alpha MOs are occupied. Add more alpha MOs to "// &
381 0 : "allow for a higher multiplicity")
382 : END IF
383 0 : IF (i < nelec) THEN
384 0 : lumo_a = lumo_a - 1
385 0 : lumo_b = lumo_b + 1
386 : END IF
387 : END IF
388 2306 : IF (lumo_b > mo_array(2)%nmo) THEN
389 34 : IF (lumo_b < lumo_a) THEN
390 : CALL cp_warn(__LOCATION__, &
391 : "All beta MOs are occupied. Add more beta MOs to "// &
392 0 : "allow for a lower multiplicity")
393 : END IF
394 34 : IF (i < nelec) THEN
395 6 : lumo_a = lumo_a + 1
396 6 : lumo_b = lumo_b - 1
397 : END IF
398 : END IF
399 : END DO
400 :
401 186 : mo_array(1)%homo = lumo_a - 1
402 186 : mo_array(2)%homo = lumo_b - 1
403 :
404 186 : IF (mo_array(2)%homo > mo_array(1)%homo) THEN
405 : CALL cp_warn(__LOCATION__, &
406 : "More beta ("// &
407 : TRIM(ADJUSTL(cp_to_string(mo_array(2)%homo)))// &
408 : ") than alpha ("// &
409 : TRIM(ADJUSTL(cp_to_string(mo_array(1)%homo)))// &
410 0 : ") MOs are occupied. Resorting to low spin state")
411 0 : mo_array(1)%homo = nelec/2 + MODULO(nelec, 2)
412 0 : mo_array(2)%homo = nelec/2
413 : END IF
414 :
415 186 : mo_array(1)%nelectron = mo_array(1)%homo
416 186 : mo_array(2)%nelectron = mo_array(2)%homo
417 186 : multiplicity_new = mo_array(1)%nelectron - mo_array(2)%nelectron + 1
418 :
419 186 : IF (multiplicity_new /= multiplicity_old) THEN
420 : CALL cp_warn(__LOCATION__, &
421 : "Multiplicity changed from "// &
422 : TRIM(ADJUSTL(cp_to_string(multiplicity_old)))//" to "// &
423 8 : TRIM(ADJUSTL(cp_to_string(multiplicity_new))))
424 : END IF
425 :
426 186 : IF (PRESENT(probe)) THEN
427 0 : CALL set_mo_occupation_1(mo_array(1), smear=smear, probe=probe)
428 0 : CALL set_mo_occupation_1(mo_array(2), smear=smear, probe=probe)
429 186 : ELSE IF (PRESENT(eval_deriv)) THEN
430 0 : CALL set_mo_occupation_1(mo_array(1), smear=smear, eval_deriv=eval_deriv)
431 0 : CALL set_mo_occupation_1(mo_array(2), smear=smear, eval_deriv=eval_deriv)
432 : ELSE
433 186 : IF (PRESENT(tot_zeff_corr)) THEN
434 0 : CALL set_mo_occupation_1(mo_array(1), smear=smear, tot_zeff_corr=tot_zeff_corr)
435 0 : CALL set_mo_occupation_1(mo_array(2), smear=smear, tot_zeff_corr=tot_zeff_corr)
436 : ELSE
437 186 : CALL set_mo_occupation_1(mo_array(1), smear=smear)
438 186 : CALL set_mo_occupation_1(mo_array(2), smear=smear)
439 : END IF
440 : END IF
441 :
442 186 : CALL timestop(handle)
443 :
444 121003 : END SUBROUTINE set_mo_occupation_2
445 :
446 : ! **************************************************************************************************
447 : !> \brief Smearing of the MO occupation with all kind of occupation numbers
448 : !> \param mo_set MO dataset structure
449 : !> \param smear optional smearing information
450 : !> \param eval_deriv on entry the derivative of the KS energy wrt to the occupation number
451 : !> on exit the derivative of the full free energy (i.e. KS and entropy) wrt to the eigenvalue
452 : !> \param xas_env ...
453 : !> \param tot_zeff_corr ...
454 : !> \param probe ...
455 : !> \param gce ...
456 : !> \param emit_warnings emit first/last-MO and electron-count warnings
457 : !> \date 17.04.2002 (v1.0), 26.08.2008 (v1.1)
458 : !> \par History
459 : !> 10.2019 Added functionality to adjust mo occupation if the core
460 : !> charges are changed via CORE_CORRECTION during surface dipole
461 : !> calculation. Total number of electrons matches the total core
462 : !> charges if tot_zeff_corr is non-zero. Not yet implemented for
463 : !> OT type method. [Soumya Ghosh]
464 : !> \author Matthias Krack
465 : !> \version 1.1
466 : ! **************************************************************************************************
467 272850 : SUBROUTINE set_mo_occupation_1(mo_set, smear, eval_deriv, xas_env, tot_zeff_corr, probe, gce, &
468 : emit_warnings)
469 :
470 : TYPE(mo_set_type), INTENT(INOUT) :: mo_set
471 : TYPE(smear_type), OPTIONAL :: smear
472 : REAL(KIND=dp), DIMENSION(:), OPTIONAL, POINTER :: eval_deriv
473 : TYPE(xas_environment_type), OPTIONAL, POINTER :: xas_env
474 : REAL(KIND=dp), OPTIONAL :: tot_zeff_corr
475 : TYPE(hairy_probes_type), DIMENSION(:), OPTIONAL, &
476 : POINTER :: probe
477 : TYPE(gce_type), OPTIONAL, POINTER :: gce
478 : LOGICAL, INTENT(IN), OPTIONAL :: emit_warnings
479 :
480 : CHARACTER(LEN=*), PARAMETER :: routineN = 'set_mo_occupation_1'
481 :
482 : CHARACTER(LEN=20) :: method_label
483 : INTEGER :: handle, i, i_first, imo, ir, irmo, nmo, &
484 : nomo, xas_estate
485 : LOGICAL :: do_gce, equal_size, is_large, &
486 : my_emit_warnings
487 : REAL(KIND=dp) :: delectron, e1, e2, edelta, edist, el_count, gce_mu, my_nelec, nelec, &
488 : occ_estate, smear_width, total_zeff_corr, xas_nelectron
489 272850 : REAL(KIND=dp), ALLOCATABLE, DIMENSION(:) :: tmp_v
490 :
491 272850 : CALL timeset(routineN, handle)
492 :
493 272850 : my_emit_warnings = .TRUE.
494 272850 : IF (PRESENT(emit_warnings)) my_emit_warnings = emit_warnings
495 :
496 272850 : CPASSERT(ASSOCIATED(mo_set%eigenvalues))
497 272850 : CPASSERT(ASSOCIATED(mo_set%occupation_numbers))
498 3033233 : mo_set%occupation_numbers(:) = 0.0_dp
499 :
500 : ! Quick return, if no electrons are available
501 272850 : IF (mo_set%nelectron == 0) THEN
502 3754 : CALL timestop(handle)
503 3754 : RETURN
504 : END IF
505 :
506 269096 : xas_estate = -1
507 269096 : occ_estate = 0.0_dp
508 269096 : IF (PRESENT(xas_env)) THEN
509 798 : CALL get_xas_env(xas_env=xas_env, xas_nelectron=xas_nelectron, occ_estate=occ_estate, xas_estate=xas_estate)
510 798 : nomo = CEILING(xas_nelectron + 1.0_dp - occ_estate - EPSILON(0.0_dp))
511 :
512 8102 : mo_set%occupation_numbers(1:nomo) = mo_set%maxocc
513 798 : IF (xas_estate > 0) mo_set%occupation_numbers(xas_estate) = occ_estate
514 8102 : el_count = SUM(mo_set%occupation_numbers(1:nomo))
515 798 : IF (el_count > xas_nelectron) THEN
516 98 : mo_set%occupation_numbers(nomo) = mo_set%occupation_numbers(nomo) - (el_count - xas_nelectron)
517 : END IF
518 8102 : el_count = SUM(mo_set%occupation_numbers(1:nomo))
519 798 : is_large = ABS(el_count - xas_nelectron) > xas_nelectron*EPSILON(el_count)
520 798 : CPASSERT(.NOT. is_large)
521 : ELSE
522 268298 : IF (PRESENT(gce)) THEN
523 208 : do_gce = gce%do_gce
524 : ELSE
525 : do_gce = .FALSE.
526 : END IF
527 : ! GCE workfunction (Fermi energy) mixing
528 208 : IF (do_gce) THEN
529 208 : smear_width = smear%smearing_width
530 208 : IF (smear%method == smear_fermi_dirac) smear_width = smear%electronic_temperature
531 208 : IF (gce%prev_workfunction < -1000.0_dp) THEN
532 8 : my_nelec = REAL(mo_set%nelectron, dp)
533 : CALL SmearFixed(mo_set%occupation_numbers, mo_set%mu, mo_set%kTS, mo_set%eigenvalues, my_nelec, &
534 8 : smear_width, mo_set%maxocc, smear%method)
535 8 : gce%prev_workfunction = -501.0_dp
536 200 : ELSE IF (gce%prev_workfunction < -500.0_dp) THEN
537 8 : my_nelec = REAL(mo_set%nelectron, dp)
538 : CALL SmearFixed(mo_set%occupation_numbers, mo_set%mu, mo_set%kTS, mo_set%eigenvalues, my_nelec, &
539 8 : smear_width, mo_set%maxocc, smear%method)
540 8 : gce%prev_workfunction = gce%ref_esp - mo_set%mu
541 : ELSE
542 : gce_mu = gce%ref_esp - ((1.0_dp - gce%mixing_coef)*gce%prev_workfunction &
543 192 : + gce%mixing_coef*gce%target_workfunction)
544 : CALL SmearOcc(mo_set%occupation_numbers, my_nelec, mo_set%kTS, mo_set%eigenvalues, gce_mu, &
545 192 : smear_width, mo_set%maxocc, smear%method)
546 192 : mo_set%mu = gce_mu
547 192 : gce%prev_workfunction = gce%ref_esp - mo_set%mu
548 192 : is_large = ABS(mo_set%occupation_numbers(1) - mo_set%maxocc) > smear%eps_fermi_dirac
549 192 : CPWARN_IF(is_large .AND. my_emit_warnings, "Fermi-Dirac smearing includes the first MO")
550 : END IF
551 1600 : DO i = 1, SIZE(mo_set%occupation_numbers)
552 1600 : IF (mo_set%occupation_numbers(i) < mo_set%maxocc) THEN
553 208 : mo_set%lfomo = i
554 208 : EXIT
555 : END IF
556 : END DO
557 2168 : DO i = SIZE(mo_set%occupation_numbers), 1, -1
558 2168 : IF (ABS(mo_set%occupation_numbers(i)) > smear%eps_fermi_dirac) THEN
559 208 : mo_set%homo = i
560 208 : EXIT
561 : END IF
562 : END DO
563 208 : mo_set%uniform_occupation = .FALSE.
564 208 : mo_set%n_el_f = my_nelec
565 208 : CALL timestop(handle)
566 208 : RETURN
567 : END IF
568 :
569 268090 : IF (MODULO(mo_set%nelectron, INT(mo_set%maxocc)) == 0) THEN
570 266994 : nomo = NINT(mo_set%nelectron/mo_set%maxocc)
571 : ! Initialize MO occupations
572 2426087 : mo_set%occupation_numbers(1:nomo) = mo_set%maxocc
573 : ELSE
574 1096 : nomo = INT(mo_set%nelectron/mo_set%maxocc) + 1
575 : ! Initialize MO occupations
576 6652 : mo_set%occupation_numbers(1:nomo - 1) = mo_set%maxocc
577 1096 : mo_set%occupation_numbers(nomo) = mo_set%nelectron - (nomo - 1)*mo_set%maxocc
578 : END IF
579 : ! introduce applied potential correction here
580 : ! electron density is adjusted according to applied core correction
581 : ! ref: SS, MT, MWF, JN PRL, 2018, 120, 246801
582 : ! see whether both surface dipole correction and core correction is present in
583 : ! the inputfile
584 268090 : IF (PRESENT(tot_zeff_corr)) THEN
585 : ! find the additional core charges
586 106 : total_zeff_corr = tot_zeff_corr
587 106 : IF (INT(mo_set%maxocc) == 1) total_zeff_corr = total_zeff_corr/2.0_dp
588 106 : delectron = 0.0_dp
589 106 : IF (total_zeff_corr < 0.0_dp) THEN
590 : ! remove electron density from the mos
591 106 : delectron = ABS(total_zeff_corr) - REAL(mo_set%maxocc, KIND=dp)
592 106 : IF (delectron > 0.0_dp) THEN
593 0 : mo_set%occupation_numbers(nomo) = 0.0_dp
594 0 : irmo = CEILING(delectron/REAL(mo_set%maxocc, KIND=dp))
595 0 : DO ir = 1, irmo
596 0 : delectron = delectron - REAL(mo_set%maxocc, KIND=dp)
597 0 : IF (delectron < 0.0_dp) THEN
598 0 : mo_set%occupation_numbers(nomo - ir) = -delectron
599 : ELSE
600 0 : mo_set%occupation_numbers(nomo - ir) = 0.0_dp
601 : END IF
602 : END DO
603 0 : nomo = nomo - irmo
604 0 : IF (mo_set%occupation_numbers(nomo) == 0.0_dp) nomo = nomo - 1
605 106 : ELSE IF (delectron < 0.0_dp) THEN
606 106 : mo_set%occupation_numbers(nomo) = -delectron
607 : ELSE
608 0 : mo_set%occupation_numbers(nomo) = 0.0_dp
609 0 : nomo = nomo - 1
610 : END IF
611 0 : ELSE IF (total_zeff_corr > 0.0_dp) THEN
612 : ! add electron density to the mos
613 0 : delectron = total_zeff_corr - REAL(mo_set%maxocc, KIND=dp)
614 0 : IF (delectron > 0.0_dp) THEN
615 0 : mo_set%occupation_numbers(nomo + 1) = REAL(mo_set%maxocc, KIND=dp)
616 0 : nomo = nomo + 1
617 0 : irmo = CEILING(delectron/REAL(mo_set%maxocc, KIND=dp))
618 0 : DO ir = 1, irmo
619 0 : delectron = delectron - REAL(mo_set%maxocc, KIND=dp)
620 0 : IF (delectron < 0.0_dp) THEN
621 0 : mo_set%occupation_numbers(nomo + ir) = delectron + REAL(mo_set%maxocc, KIND=dp)
622 : ELSE
623 0 : mo_set%occupation_numbers(nomo + ir) = REAL(mo_set%maxocc, KIND=dp)
624 : END IF
625 : END DO
626 0 : nomo = nomo + irmo
627 : ELSE
628 0 : mo_set%occupation_numbers(nomo + 1) = total_zeff_corr
629 0 : nomo = nomo + 1
630 : END IF
631 : END IF
632 : END IF
633 : END IF
634 268888 : nmo = SIZE(mo_set%eigenvalues)
635 :
636 268888 : CPASSERT(nmo >= nomo)
637 268888 : CPASSERT((SIZE(mo_set%occupation_numbers) == nmo))
638 :
639 268888 : mo_set%homo = nomo
640 268888 : mo_set%lfomo = nomo + 1
641 268888 : mo_set%mu = mo_set%eigenvalues(nomo)
642 :
643 : ! Check consistency of the array lengths
644 268888 : IF (PRESENT(eval_deriv)) THEN
645 0 : equal_size = (SIZE(mo_set%occupation_numbers, 1) == SIZE(eval_deriv, 1))
646 0 : CPASSERT(equal_size)
647 : END IF
648 :
649 : !calling of HP module HERE, before smear
650 268888 : IF (PRESENT(probe)) THEN
651 14 : i_first = 1
652 14 : IF (smear%fixed_mag_mom == -1.0_dp) THEN
653 0 : nelec = REAL(mo_set%nelectron, dp)
654 : ELSE
655 14 : nelec = mo_set%n_el_f
656 : END IF
657 :
658 294 : mo_set%occupation_numbers(:) = 0.0_dp
659 :
660 : CALL probe_occupancy(mo_set%occupation_numbers, mo_set%mu, mo_set%kTS, &
661 : mo_set%eigenvalues, mo_set%mo_coeff, mo_set%maxocc, &
662 14 : probe, N=nelec)
663 : !NB: mu and T are taken from the hairy_probe type (defined in cp_control_types.F); these values are set in the input
664 :
665 : ! Find the lowest fractional occupied MO (LFOMO)
666 198 : DO imo = i_first, nmo
667 198 : IF (mo_set%occupation_numbers(imo) < mo_set%maxocc) THEN
668 14 : mo_set%lfomo = imo
669 14 : EXIT
670 : END IF
671 : END DO
672 294 : is_large = ABS(MAXVAL(mo_set%occupation_numbers) - mo_set%maxocc) > probe(1)%eps_hp
673 : ! this is not a real problem, but the temperature might be a bit large
674 14 : IF (is_large .AND. my_emit_warnings) THEN
675 0 : CPWARN("Hair-probes occupancy distribution includes the first MO")
676 : END IF
677 :
678 : ! Find the highest (fractional) occupied MO which will be now the HOMO
679 22 : DO imo = nmo, mo_set%lfomo, -1
680 22 : IF (mo_set%occupation_numbers(imo) > probe(1)%eps_hp) THEN
681 14 : mo_set%homo = imo
682 14 : EXIT
683 : END IF
684 : END DO
685 294 : is_large = ABS(MINVAL(mo_set%occupation_numbers)) > probe(1)%eps_hp
686 14 : IF (is_large .AND. my_emit_warnings) THEN
687 : CALL cp_warn(__LOCATION__, &
688 : "Hair-probes occupancy distribution includes the last MO => "// &
689 6 : "Add more MOs for proper smearing.")
690 : END IF
691 :
692 : ! check that the total electron count is accurate
693 14 : is_large = (ABS(nelec - accurate_sum(mo_set%occupation_numbers(:))) > probe(1)%eps_hp*nelec)
694 14 : IF (is_large .AND. my_emit_warnings) THEN
695 0 : CPWARN("Total number of electrons is not accurate")
696 : END IF
697 :
698 : END IF
699 :
700 : ! Quick return, if no smearing information is supplied (TO BE FIXED, smear should become non-optional...)
701 268888 : IF (.NOT. PRESENT(smear)) THEN
702 : ! there is no dependence of the energy on the eigenvalues
703 230 : mo_set%uniform_occupation = .TRUE.
704 230 : IF (PRESENT(eval_deriv)) THEN
705 0 : eval_deriv = 0.0_dp
706 : END IF
707 230 : CALL timestop(handle)
708 230 : RETURN
709 : END IF
710 :
711 : ! Check if proper eigenvalues are already available
712 268658 : IF (smear%method /= smear_list) THEN
713 268658 : IF ((ABS(mo_set%eigenvalues(1)) < 1.0E-12_dp) .AND. &
714 : (ABS(mo_set%eigenvalues(nmo)) < 1.0E-12_dp)) THEN
715 60924 : CALL timestop(handle)
716 60924 : RETURN
717 : END IF
718 : END IF
719 :
720 : ! Perform smearing
721 207734 : IF (smear%do_smear) THEN
722 24450 : IF (PRESENT(xas_env)) THEN
723 30 : i_first = xas_estate + 1
724 30 : nelec = xas_nelectron
725 : ELSE
726 24420 : i_first = 1
727 24420 : IF (smear%fixed_mag_mom == -1.0_dp) THEN
728 782 : nelec = REAL(mo_set%nelectron, dp)
729 : ELSE
730 23638 : nelec = mo_set%n_el_f
731 : END IF
732 : END IF
733 22896 : SELECT CASE (smear%method)
734 : CASE (smear_fermi_dirac)
735 22896 : IF (.NOT. PRESENT(eval_deriv)) THEN
736 : CALL SmearFixed(mo_set%occupation_numbers(1:mo_set%nmo), mo_set%mu, mo_set%kTS, &
737 : mo_set%eigenvalues(1:mo_set%nmo), Nelec, &
738 : smear%electronic_temperature, mo_set%maxocc, smear_fermi_dirac, &
739 22896 : xas_estate, occ_estate)
740 : ELSE
741 0 : IF (.NOT. ALLOCATED(tmp_v)) ALLOCATE (tmp_v(SIZE(eval_deriv)))
742 0 : tmp_v(:) = eval_deriv - mo_set%eigenvalues + mo_set%mu
743 : CALL SmearFixedDerivMV(eval_deriv, mo_set%occupation_numbers(1:mo_set%nmo), mo_set%mu, &
744 : mo_set%kTS, mo_set%eigenvalues(1:mo_set%nmo), Nelec, &
745 : smear%electronic_temperature, mo_set%maxocc, smear_fermi_dirac, &
746 0 : tmp_v, xas_estate, occ_estate)
747 : END IF
748 :
749 : ! Find the lowest fractional occupied MO (LFOMO)
750 209632 : DO imo = i_first, nmo
751 209632 : IF (mo_set%occupation_numbers(imo) < mo_set%maxocc) THEN
752 22896 : mo_set%lfomo = imo
753 22896 : EXIT
754 : END IF
755 : END DO
756 22896 : IF (i_first <= nmo) THEN
757 22896 : is_large = ABS(mo_set%occupation_numbers(i_first) - mo_set%maxocc) > smear%eps_fermi_dirac
758 : ELSE
759 : is_large = .FALSE.
760 : END IF
761 : ! this is not a real problem, but the temperature might be a bit large
762 22896 : CPWARN_IF(is_large .AND. my_emit_warnings, "Fermi-Dirac smearing includes the first MO")
763 :
764 : ! Find the highest (fractional) occupied MO which will be now the HOMO
765 423970 : DO imo = nmo, mo_set%lfomo, -1
766 423970 : IF (mo_set%occupation_numbers(imo) > smear%eps_fermi_dirac) THEN
767 14964 : mo_set%homo = imo
768 14964 : EXIT
769 : END IF
770 : END DO
771 674006 : is_large = ABS(MINVAL(mo_set%occupation_numbers)) > smear%eps_fermi_dirac
772 22896 : IF (is_large .AND. my_emit_warnings) THEN
773 : CALL cp_warn(__LOCATION__, &
774 : "Fermi-Dirac smearing includes the last MO => "// &
775 684 : "Add more MOs for proper smearing.")
776 : END IF
777 :
778 : ! check that the total electron count is accurate
779 22896 : is_large = (ABS(nelec - accurate_sum(mo_set%occupation_numbers(:))) > smear%eps_fermi_dirac*nelec)
780 22896 : CPWARN_IF(is_large .AND. my_emit_warnings, "Total number of electrons is not accurate")
781 :
782 : CASE (smear_gaussian, smear_mp, smear_mv)
783 1396 : IF (.NOT. PRESENT(eval_deriv)) THEN
784 : CALL SmearFixed(mo_set%occupation_numbers(1:mo_set%nmo), mo_set%mu, mo_set%kTS, &
785 : mo_set%eigenvalues(1:mo_set%nmo), Nelec, &
786 : smear%smearing_width, mo_set%maxocc, smear%method, &
787 1396 : xas_estate, occ_estate)
788 : ELSE
789 0 : IF (.NOT. ALLOCATED(tmp_v)) ALLOCATE (tmp_v(SIZE(eval_deriv)))
790 0 : tmp_v(:) = eval_deriv - mo_set%eigenvalues + mo_set%mu
791 : CALL SmearFixedDerivMV(eval_deriv, mo_set%occupation_numbers(1:mo_set%nmo), mo_set%mu, &
792 : mo_set%kTS, mo_set%eigenvalues(1:mo_set%nmo), Nelec, &
793 : smear%smearing_width, mo_set%maxocc, smear%method, &
794 0 : tmp_v, xas_estate, occ_estate)
795 : END IF
796 :
797 : ! Method label for warnings
798 2792 : SELECT CASE (smear%method)
799 : CASE (smear_gaussian)
800 1396 : method_label = "Gaussian"
801 : CASE (smear_mp)
802 0 : method_label = "Methfessel-Paxton"
803 : CASE (smear_mv)
804 1396 : method_label = "Marzari-Vanderbilt"
805 : END SELECT
806 :
807 : ! Find the lowest fractional occupied MO (LFOMO)
808 18004 : DO imo = i_first, nmo
809 18004 : IF (ABS(mo_set%occupation_numbers(imo) - mo_set%maxocc) > smear%eps_fermi_dirac) THEN
810 1396 : mo_set%lfomo = imo
811 1396 : EXIT
812 : END IF
813 : END DO
814 1396 : IF (i_first <= nmo) THEN
815 1396 : is_large = ABS(mo_set%occupation_numbers(i_first) - mo_set%maxocc) > smear%eps_fermi_dirac
816 : ELSE
817 : is_large = .FALSE.
818 : END IF
819 1396 : IF (is_large .AND. my_emit_warnings) THEN
820 0 : CPWARN(TRIM(method_label)//" smearing includes the first MO")
821 : END IF
822 :
823 : ! Find the highest (fractional) occupied MO which will be now the HOMO
824 17210 : DO imo = nmo, mo_set%lfomo, -1
825 17210 : IF (ABS(mo_set%occupation_numbers(imo)) > smear%eps_fermi_dirac) THEN
826 964 : mo_set%homo = imo
827 964 : EXIT
828 : END IF
829 : END DO
830 1396 : is_large = ABS(mo_set%occupation_numbers(nmo)) > smear%eps_fermi_dirac
831 1396 : IF (is_large .AND. my_emit_warnings) THEN
832 : CALL cp_warn(__LOCATION__, &
833 : TRIM(method_label)//" smearing includes the last MO => "// &
834 0 : "Add more MOs for proper smearing.")
835 : END IF
836 :
837 : ! Check that the total electron count is accurate
838 1396 : is_large = (ABS(nelec - accurate_sum(mo_set%occupation_numbers(:))) > smear%eps_fermi_dirac*nelec)
839 1396 : CPWARN_IF(is_large .AND. my_emit_warnings, "Total number of electrons is not accurate")
840 :
841 : CASE (smear_energy_window)
842 : ! not implemented
843 158 : CPASSERT(.NOT. PRESENT(eval_deriv))
844 :
845 : ! Define the energy window for the eigenvalues
846 158 : e1 = mo_set%eigenvalues(mo_set%homo) - 0.5_dp*smear%window_size
847 158 : IF (e1 <= mo_set%eigenvalues(1) .AND. my_emit_warnings) THEN
848 0 : CPWARN("Energy window for smearing includes the first MO")
849 : END IF
850 :
851 158 : e2 = mo_set%eigenvalues(mo_set%homo) + 0.5_dp*smear%window_size
852 158 : IF (e2 >= mo_set%eigenvalues(nmo) .AND. my_emit_warnings) THEN
853 : CALL cp_warn(__LOCATION__, &
854 : "Energy window for smearing includes the last MO => "// &
855 0 : "Add more MOs for proper smearing.")
856 : END IF
857 :
858 : ! Find the lowest fractional occupied MO (LFOMO)
859 2636 : DO imo = i_first, nomo
860 2636 : IF (mo_set%eigenvalues(imo) > e1) THEN
861 158 : mo_set%lfomo = imo
862 158 : EXIT
863 : END IF
864 : END DO
865 :
866 : ! Find the highest fractional occupied (non-zero) MO which will be the HOMO
867 1344 : DO imo = nmo, nomo, -1
868 1344 : IF (mo_set%eigenvalues(imo) < e2) THEN
869 158 : mo_set%homo = imo
870 158 : EXIT
871 : END IF
872 : END DO
873 :
874 : ! Get the number of electrons to be smeared
875 158 : edist = 0.0_dp
876 158 : nelec = 0.0_dp
877 :
878 390 : DO imo = mo_set%lfomo, mo_set%homo
879 232 : nelec = nelec + mo_set%occupation_numbers(imo)
880 390 : edist = edist + ABS(e2 - mo_set%eigenvalues(imo))
881 : END DO
882 :
883 : ! Smear electrons inside the energy window
884 390 : DO imo = mo_set%lfomo, mo_set%homo
885 232 : edelta = ABS(e2 - mo_set%eigenvalues(imo))
886 232 : mo_set%occupation_numbers(imo) = MIN(mo_set%maxocc, nelec*edelta/edist)
887 232 : nelec = nelec - mo_set%occupation_numbers(imo)
888 390 : edist = edist - edelta
889 : END DO
890 :
891 : CASE (smear_list)
892 0 : equal_size = SIZE(mo_set%occupation_numbers, 1) == SIZE(smear%list, 1)
893 0 : CPASSERT(equal_size)
894 0 : mo_set%occupation_numbers = smear%list
895 : ! there is no dependence of the energy on the eigenvalues
896 0 : IF (PRESENT(eval_deriv)) THEN
897 0 : eval_deriv = 0.0_dp
898 : END IF
899 : ! most general case
900 0 : mo_set%lfomo = 1
901 24450 : mo_set%homo = nmo
902 : END SELECT
903 :
904 : ! Check, if the smearing involves more than one MO
905 24450 : IF (mo_set%lfomo == mo_set%homo) THEN
906 1578 : mo_set%homo = nomo
907 1578 : mo_set%lfomo = nomo + 1
908 : ELSE
909 22872 : mo_set%uniform_occupation = .FALSE.
910 : END IF
911 :
912 : END IF ! do smear
913 :
914 : ! zeros don't count as uniform
915 207734 : mo_set%uniform_occupation = has_uniform_occupation(mo_set=mo_set)
916 :
917 207734 : IF (ALLOCATED(tmp_v)) DEALLOCATE (tmp_v)
918 207734 : CALL timestop(handle)
919 :
920 207734 : END SUBROUTINE set_mo_occupation_1
921 :
922 : END MODULE qs_mo_occupation
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