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qs_mo_occupation.F
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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
15MODULE 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
54CONTAINS
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 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 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 REAL(KIND=dp), DIMENSION(:), POINTER :: eigval_a, eigval_b, occ_a, occ_b
85
86 CALL timeset(routinen, handle)
87
88 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 occupation_numbers=occ_a)
91 CALL get_mo_set(mo_set=mo_array(2), nmo=nmo_b, eigenvalues=eigval_b, &
92 occupation_numbers=occ_b)
93 all_nmo = nmo_a + nmo_b
94 ALLOCATE (all_eigval(all_nmo))
95 ALLOCATE (all_occ(all_nmo))
96 ALLOCATE (all_index(all_nmo))
97
98 all_eigval(1:nmo_a) = eigval_a(1:nmo_a)
99 all_eigval(nmo_a + 1:all_nmo) = eigval_b(1:nmo_b)
100
101 CALL sort(all_eigval, all_nmo, all_index)
102
103 IF (PRESENT(gce)) THEN
104 do_gce = gce%do_gce
105 ELSE
106 do_gce = .false.
107 END IF
108
109 SELECT CASE (smear%method)
110 CASE (smear_fermi_dirac)
111 smear_width = smear%electronic_temperature
112 method_label = "Fermi-Dirac"
113 CASE (smear_gaussian)
114 smear_width = smear%smearing_width
115 method_label = "Gaussian"
116 CASE (smear_mp)
117 smear_width = smear%smearing_width
118 method_label = "Methfessel-Paxton"
119 CASE (smear_mv)
120 smear_width = smear%smearing_width
121 method_label = "Marzari-Vanderbilt"
122 CASE DEFAULT
123 cpabort("set_mo_occupation_3: unsupported smearing method")
124 END SELECT
125
126 IF (.NOT. do_gce) THEN
127 xas_estate = -1
128 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 nelec_a = accurate_sum(occ_a(:))
134 nelec_b = accurate_sum(occ_b(:))
135 all_nelec = nelec_a + nelec_b
136
137 DO i = 1, all_nmo
138 IF (all_index(i) <= nmo_a) THEN
139 all_occ(i) = occ_a(all_index(i))
140 ELSE
141 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 smear_width, 1._dp, smear%method, xas_estate, occ_estate)
147 ELSE
148 gce%prev_workfunction = gce%ref_esp - mo_array(1)%mu
149 mu = gce%ref_esp - ((1.0_dp - gce%mixing_coef)*gce%prev_workfunction + gce%mixing_coef*gce%target_workfunction)
150 CALL smearocc(all_occ, all_nelec, kts, all_eigval, mu, smear_width, 1._dp, smear%method)
151 END IF
152
153 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 cpwarn_if(is_large, trim(method_label)//" smearing includes the first MO")
156
157 is_large = abs(all_occ(all_nmo)) > smear%eps_fermi_dirac
158 IF (is_large) THEN
159 CALL cp_warn(__location__, &
160 trim(method_label)//" smearing includes the last MO => "// &
161 "Add more MOs for proper smearing.")
162 END IF
163 IF (.NOT. do_gce) THEN
164 ! check that the total electron count is accurate
165 is_large = (abs(all_nelec - accurate_sum(all_occ(:))) > smear%eps_fermi_dirac*all_nelec)
166 cpwarn_if(is_large, "Total number of electrons is not accurate")
167 END IF
168
169 DO i = 1, all_nmo
170 IF (all_index(i) <= nmo_a) THEN
171 occ_a(all_index(i)) = all_occ(i)
172 eigval_a(all_index(i)) = all_eigval(i)
173 ELSE
174 occ_b(all_index(i) - nmo_a) = all_occ(i)
175 eigval_b(all_index(i) - nmo_a) = all_eigval(i)
176 END IF
177 END DO
178
179 nelec_a = accurate_sum(occ_a(:))
180 nelec_b = accurate_sum(occ_b(:))
181
182 lfomo_a = nmo_a + 1
183 lfomo_b = nmo_b + 1
184 homo_a = 0
185 homo_b = 0
186
187 DO i = 1, nmo_a
188 IF (occ_a(i) < 1.0_dp) THEN
189 lfomo_a = i
190 EXIT
191 END IF
192 END DO
193 DO i = 1, nmo_b
194 IF (occ_b(i) < 1.0_dp) THEN
195 lfomo_b = i
196 EXIT
197 END IF
198 END DO
199 homo_a = lfomo_a - 1
200 DO i = nmo_a, lfomo_a, -1
201 IF (occ_a(i) > smear%eps_fermi_dirac) THEN
202 homo_a = i
203 EXIT
204 END IF
205 END DO
206 homo_b = lfomo_b - 1
207 DO i = nmo_b, lfomo_b, -1
208 IF (occ_b(i) > smear%eps_fermi_dirac) THEN
209 homo_b = i
210 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 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 lfomo=lfomo_b, homo=homo_b, uniform_occupation=.false.)
218
219 CALL timestop(handle)
220
221 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 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 REAL(KIND=dp), DIMENSION(:), POINTER :: eigval_a, eigval_b
259
260 CALL timeset(routinen, handle)
261
262 ! Fall back for the case that we have only one MO set
263 IF (SIZE(mo_array) == 1) THEN
264 IF (PRESENT(probe)) THEN
265 CALL set_mo_occupation_1(mo_array(1), smear=smear, probe=probe)
266 ELSE IF (PRESENT(eval_deriv)) THEN
267! Change of MO occupancy to account for CORE_CORRECTION is not yet implemented
268 IF (PRESENT(gce)) THEN
269 CALL set_mo_occupation_1(mo_array(1), smear=smear, eval_deriv=eval_deriv, gce=gce)
270 ELSE
271 CALL set_mo_occupation_1(mo_array(1), smear=smear, eval_deriv=eval_deriv)
272 END IF
273 ELSE
274 IF (PRESENT(tot_zeff_corr)) THEN
275 CALL set_mo_occupation_1(mo_array(1), smear=smear, tot_zeff_corr=tot_zeff_corr)
276 ELSE
277 IF (PRESENT(gce)) THEN
278 CALL set_mo_occupation_1(mo_array(1), smear=smear, gce=gce)
279 ELSE
280 CALL set_mo_occupation_1(mo_array(1), smear=smear)
281 END IF
282 END IF
283 END IF
284 CALL timestop(handle)
285 RETURN
286 END IF
287
288 IF (PRESENT(probe)) THEN
289 CALL set_mo_occupation_1(mo_array(1), smear=smear, probe=probe)
290 CALL set_mo_occupation_1(mo_array(2), smear=smear, probe=probe)
291 END IF
292
293 IF (smear%do_smear) THEN
294 IF (smear%fixed_mag_mom < 0.0_dp) THEN
295 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 "to correct the electron density")
302 END IF
303 IF (smear%fixed_mag_mom /= -1.0_dp) THEN
304 cpassert(.NOT. (PRESENT(eval_deriv)))
305 CALL set_mo_occupation_3(mo_array, smear=smear, gce=gce)
306 CALL timestop(handle)
307 RETURN
308 END IF
309 ELSE
310 nelec_f = mo_array(1)%n_el_f + mo_array(2)%n_el_f
311 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 mo_array(1)%n_el_f = nelec_f/2.0_dp + smear%fixed_mag_mom/2.0_dp
313 mo_array(2)%n_el_f = nelec_f/2.0_dp - smear%fixed_mag_mom/2.0_dp
314 END IF
315 cpassert(.NOT. (PRESENT(eval_deriv)))
316 IF (PRESENT(tot_zeff_corr)) THEN
317 CALL set_mo_occupation_1(mo_array(1), smear=smear, tot_zeff_corr=tot_zeff_corr)
318 CALL set_mo_occupation_1(mo_array(2), smear=smear, tot_zeff_corr=tot_zeff_corr)
319 ELSE
320 CALL set_mo_occupation_1(mo_array(1), smear=smear)
321 CALL set_mo_occupation_1(mo_array(2), smear=smear)
322 END IF
323 END IF
324 END IF
325
326 IF (.NOT. ((mo_array(1)%flexible_electron_count > 0.0_dp) .AND. &
327 (mo_array(2)%flexible_electron_count > 0.0_dp))) THEN
328 IF (PRESENT(probe)) THEN
329 CALL set_mo_occupation_1(mo_array(1), smear=smear, probe=probe)
330 CALL set_mo_occupation_1(mo_array(2), smear=smear, probe=probe)
331 ELSE IF (PRESENT(eval_deriv)) THEN
332 CALL set_mo_occupation_1(mo_array(1), smear=smear, eval_deriv=eval_deriv)
333 CALL set_mo_occupation_1(mo_array(2), smear=smear, eval_deriv=eval_deriv)
334 ELSE
335 IF (PRESENT(tot_zeff_corr)) THEN
336 CALL set_mo_occupation_1(mo_array(1), smear=smear, tot_zeff_corr=tot_zeff_corr)
337 CALL set_mo_occupation_1(mo_array(2), smear=smear, tot_zeff_corr=tot_zeff_corr)
338 ELSE
339 CALL set_mo_occupation_1(mo_array(1), smear=smear)
340 CALL set_mo_occupation_1(mo_array(2), smear=smear)
341 END IF
342 END IF
343 CALL timestop(handle)
344 RETURN
345 END IF
346
347 nelec = mo_array(1)%nelectron + mo_array(2)%nelectron
348
349 multiplicity_old = mo_array(1)%nelectron - mo_array(2)%nelectron + 1
350
351 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 "allow for a higher multiplicity")
355 END IF
356 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 "allow for a lower multiplicity")
359 END IF
360
361 eigval_a => mo_array(1)%eigenvalues
362 eigval_b => mo_array(2)%eigenvalues
363
364 lumo_a = 1
365 lumo_b = 1
366
367 ! Apply Aufbau principle
368 DO i = 1, nelec
369 ! Threshold is needed to ensure a preference for alpha occupation in the case
370 ! of degeneracy
371 threshold = max(mo_array(1)%flexible_electron_count, mo_array(2)%flexible_electron_count)
372 IF ((eigval_a(lumo_a) - threshold) < eigval_b(lumo_b)) THEN
373 lumo_a = lumo_a + 1
374 ELSE
375 lumo_b = lumo_b + 1
376 END IF
377 IF (lumo_a > mo_array(1)%nmo) THEN
378 IF (i /= nelec) THEN
379 CALL cp_warn(__location__, &
380 "All alpha MOs are occupied. Add more alpha MOs to "// &
381 "allow for a higher multiplicity")
382 END IF
383 IF (i < nelec) THEN
384 lumo_a = lumo_a - 1
385 lumo_b = lumo_b + 1
386 END IF
387 END IF
388 IF (lumo_b > mo_array(2)%nmo) THEN
389 IF (lumo_b < lumo_a) THEN
390 CALL cp_warn(__location__, &
391 "All beta MOs are occupied. Add more beta MOs to "// &
392 "allow for a lower multiplicity")
393 END IF
394 IF (i < nelec) THEN
395 lumo_a = lumo_a + 1
396 lumo_b = lumo_b - 1
397 END IF
398 END IF
399 END DO
400
401 mo_array(1)%homo = lumo_a - 1
402 mo_array(2)%homo = lumo_b - 1
403
404 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 ") MOs are occupied. Resorting to low spin state")
411 mo_array(1)%homo = nelec/2 + modulo(nelec, 2)
412 mo_array(2)%homo = nelec/2
413 END IF
414
415 mo_array(1)%nelectron = mo_array(1)%homo
416 mo_array(2)%nelectron = mo_array(2)%homo
417 multiplicity_new = mo_array(1)%nelectron - mo_array(2)%nelectron + 1
418
419 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 trim(adjustl(cp_to_string(multiplicity_new))))
424 END IF
425
426 IF (PRESENT(probe)) THEN
427 CALL set_mo_occupation_1(mo_array(1), smear=smear, probe=probe)
428 CALL set_mo_occupation_1(mo_array(2), smear=smear, probe=probe)
429 ELSE IF (PRESENT(eval_deriv)) THEN
430 CALL set_mo_occupation_1(mo_array(1), smear=smear, eval_deriv=eval_deriv)
431 CALL set_mo_occupation_1(mo_array(2), smear=smear, eval_deriv=eval_deriv)
432 ELSE
433 IF (PRESENT(tot_zeff_corr)) THEN
434 CALL set_mo_occupation_1(mo_array(1), smear=smear, tot_zeff_corr=tot_zeff_corr)
435 CALL set_mo_occupation_1(mo_array(2), smear=smear, tot_zeff_corr=tot_zeff_corr)
436 ELSE
437 CALL set_mo_occupation_1(mo_array(1), smear=smear)
438 CALL set_mo_occupation_1(mo_array(2), smear=smear)
439 END IF
440 END IF
441
442 CALL timestop(handle)
443
444 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!> \date 17.04.2002 (v1.0), 26.08.2008 (v1.1)
457!> \par History
458!> 10.2019 Added functionality to adjust mo occupation if the core
459!> charges are changed via CORE_CORRECTION during surface dipole
460!> calculation. Total number of electrons matches the total core
461!> charges if tot_zeff_corr is non-zero. Not yet implemented for
462!> OT type method. [Soumya Ghosh]
463!> \author Matthias Krack
464!> \version 1.1
465! **************************************************************************************************
466 SUBROUTINE set_mo_occupation_1(mo_set, smear, eval_deriv, xas_env, tot_zeff_corr, probe, gce)
467
468 TYPE(mo_set_type), INTENT(INOUT) :: mo_set
469 TYPE(smear_type), OPTIONAL :: smear
470 REAL(KIND=dp), DIMENSION(:), OPTIONAL, POINTER :: eval_deriv
471 TYPE(xas_environment_type), OPTIONAL, POINTER :: xas_env
472 REAL(kind=dp), OPTIONAL :: tot_zeff_corr
473 TYPE(hairy_probes_type), DIMENSION(:), OPTIONAL, &
474 POINTER :: probe
475 TYPE(gce_type), OPTIONAL, POINTER :: gce
476
477 CHARACTER(LEN=*), PARAMETER :: routineN = 'set_mo_occupation_1'
478
479 CHARACTER(LEN=20) :: method_label
480 INTEGER :: handle, i, i_first, imo, ir, irmo, nmo, &
481 nomo, xas_estate
482 LOGICAL :: do_gce, equal_size, is_large
483 REAL(KIND=dp) :: delectron, e1, e2, edelta, edist, &
484 el_count, gce_mu, my_nelec, nelec, &
485 occ_estate, total_zeff_corr, &
486 xas_nelectron
487 REAL(KIND=dp), ALLOCATABLE, DIMENSION(:) :: tmp_v
488
489 CALL timeset(routinen, handle)
490
491 cpassert(ASSOCIATED(mo_set%eigenvalues))
492 cpassert(ASSOCIATED(mo_set%occupation_numbers))
493 mo_set%occupation_numbers(:) = 0.0_dp
494
495 ! Quick return, if no electrons are available
496 IF (mo_set%nelectron == 0) THEN
497 CALL timestop(handle)
498 RETURN
499 END IF
500
501 xas_estate = -1
502 occ_estate = 0.0_dp
503 IF (PRESENT(xas_env)) THEN
504 CALL get_xas_env(xas_env=xas_env, xas_nelectron=xas_nelectron, occ_estate=occ_estate, xas_estate=xas_estate)
505 nomo = ceiling(xas_nelectron + 1.0 - occ_estate - epsilon(0.0_dp))
506
507 mo_set%occupation_numbers(1:nomo) = mo_set%maxocc
508 IF (xas_estate > 0) mo_set%occupation_numbers(xas_estate) = occ_estate
509 el_count = sum(mo_set%occupation_numbers(1:nomo))
510 IF (el_count > xas_nelectron) THEN
511 mo_set%occupation_numbers(nomo) = mo_set%occupation_numbers(nomo) - (el_count - xas_nelectron)
512 END IF
513 el_count = sum(mo_set%occupation_numbers(1:nomo))
514 is_large = abs(el_count - xas_nelectron) > xas_nelectron*epsilon(el_count)
515 cpassert(.NOT. is_large)
516 ELSE
517 IF (PRESENT(gce)) THEN
518 do_gce = gce%do_gce
519 ELSE
520 do_gce = .false.
521 END IF
522 ! GCE workfunction (Fermi energy) mixing
523 IF (do_gce) THEN
524 IF (smear%method /= smear_fermi_dirac) THEN
525 cpabort("Grand canonical ensemble DFT SCF now only support Fermi Dirac smearing.")
526 END IF
527 IF (gce%prev_workfunction < -1000.0_dp) THEN
528 my_nelec = real(mo_set%nelectron, dp)
529 CALL smearfixed(mo_set%occupation_numbers, mo_set%mu, mo_set%kTS, mo_set%eigenvalues, my_nelec, &
530 smear%electronic_temperature, mo_set%maxocc, smear_fermi_dirac)
531 gce%prev_workfunction = -501.0_dp
532 ELSE IF (gce%prev_workfunction < -500.0_dp) THEN
533 my_nelec = real(mo_set%nelectron, dp)
534 CALL smearfixed(mo_set%occupation_numbers, mo_set%mu, mo_set%kTS, mo_set%eigenvalues, my_nelec, &
535 smear%electronic_temperature, mo_set%maxocc, smear_fermi_dirac)
536 gce%prev_workfunction = gce%ref_esp - mo_set%mu
537 ELSE
538 gce_mu = gce%ref_esp - ((1.0_dp - gce%mixing_coef)*gce%prev_workfunction &
539 + gce%mixing_coef*gce%target_workfunction)
540 CALL smearocc(mo_set%occupation_numbers, my_nelec, mo_set%kTS, mo_set%eigenvalues, gce_mu, &
541 smear%electronic_temperature, mo_set%maxocc, smear_fermi_dirac)
542 mo_set%mu = gce_mu
543 gce%prev_workfunction = gce%ref_esp - mo_set%mu
544 is_large = abs(maxval(mo_set%occupation_numbers) - mo_set%maxocc) > smear%eps_fermi_dirac
545 cpwarn_if(is_large, "Fermi-Dirac smearing includes the first MO")
546 END IF
547 DO i = 1, SIZE(mo_set%occupation_numbers)
548 IF (mo_set%occupation_numbers(i) < mo_set%maxocc) THEN
549 mo_set%lfomo = i
550 EXIT
551 END IF
552 END DO
553 DO i = SIZE(mo_set%occupation_numbers), 1, -1
554 IF (mo_set%occupation_numbers(i) > smear%eps_fermi_dirac) THEN
555 mo_set%homo = i
556 EXIT
557 END IF
558 END DO
559 mo_set%uniform_occupation = .false.
560 mo_set%n_el_f = my_nelec
561 CALL timestop(handle)
562 RETURN
563 END IF
564
565 IF (modulo(mo_set%nelectron, int(mo_set%maxocc)) == 0) THEN
566 nomo = nint(mo_set%nelectron/mo_set%maxocc)
567 ! Initialize MO occupations
568 mo_set%occupation_numbers(1:nomo) = mo_set%maxocc
569 ELSE
570 nomo = int(mo_set%nelectron/mo_set%maxocc) + 1
571 ! Initialize MO occupations
572 mo_set%occupation_numbers(1:nomo - 1) = mo_set%maxocc
573 mo_set%occupation_numbers(nomo) = mo_set%nelectron - (nomo - 1)*mo_set%maxocc
574 END IF
575! introduce applied potential correction here
576! electron density is adjusted according to applied core correction
577! ref: SS, MT, MWF, JN PRL, 2018, 120, 246801
578! see whether both surface dipole correction and core correction is present in
579! the inputfile
580 IF (PRESENT(tot_zeff_corr)) THEN
581! find the additional core charges
582 total_zeff_corr = tot_zeff_corr
583 IF (int(mo_set%maxocc) == 1) total_zeff_corr = total_zeff_corr/2.0_dp
584 delectron = 0.0_dp
585 IF (total_zeff_corr < 0.0_dp) THEN
586! remove electron density from the mos
587 delectron = abs(total_zeff_corr) - real(mo_set%maxocc, kind=dp)
588 IF (delectron > 0.0_dp) THEN
589 mo_set%occupation_numbers(nomo) = 0.0_dp
590 irmo = ceiling(delectron/real(mo_set%maxocc, kind=dp))
591 DO ir = 1, irmo
592 delectron = delectron - real(mo_set%maxocc, kind=dp)
593 IF (delectron < 0.0_dp) THEN
594 mo_set%occupation_numbers(nomo - ir) = -delectron
595 ELSE
596 mo_set%occupation_numbers(nomo - ir) = 0.0_dp
597 END IF
598 END DO
599 nomo = nomo - irmo
600 IF (mo_set%occupation_numbers(nomo) == 0.0_dp) nomo = nomo - 1
601 ELSE IF (delectron < 0.0_dp) THEN
602 mo_set%occupation_numbers(nomo) = -delectron
603 ELSE
604 mo_set%occupation_numbers(nomo) = 0.0_dp
605 nomo = nomo - 1
606 END IF
607 ELSE IF (total_zeff_corr > 0.0_dp) THEN
608! add electron density to the mos
609 delectron = total_zeff_corr - real(mo_set%maxocc, kind=dp)
610 IF (delectron > 0.0_dp) THEN
611 mo_set%occupation_numbers(nomo + 1) = real(mo_set%maxocc, kind=dp)
612 nomo = nomo + 1
613 irmo = ceiling(delectron/real(mo_set%maxocc, kind=dp))
614 DO ir = 1, irmo
615 delectron = delectron - real(mo_set%maxocc, kind=dp)
616 IF (delectron < 0.0_dp) THEN
617 mo_set%occupation_numbers(nomo + ir) = delectron + real(mo_set%maxocc, kind=dp)
618 ELSE
619 mo_set%occupation_numbers(nomo + ir) = real(mo_set%maxocc, kind=dp)
620 END IF
621 END DO
622 nomo = nomo + irmo
623 ELSE
624 mo_set%occupation_numbers(nomo + 1) = total_zeff_corr
625 nomo = nomo + 1
626 END IF
627 END IF
628 END IF
629 END IF
630 nmo = SIZE(mo_set%eigenvalues)
631
632 cpassert(nmo >= nomo)
633 cpassert((SIZE(mo_set%occupation_numbers) == nmo))
634
635 mo_set%homo = nomo
636 mo_set%lfomo = nomo + 1
637 mo_set%mu = mo_set%eigenvalues(nomo)
638
639 ! Check consistency of the array lengths
640 IF (PRESENT(eval_deriv)) THEN
641 equal_size = (SIZE(mo_set%occupation_numbers, 1) == SIZE(eval_deriv, 1))
642 cpassert(equal_size)
643 END IF
644
645!calling of HP module HERE, before smear
646 IF (PRESENT(probe)) THEN
647 i_first = 1
648 IF (smear%fixed_mag_mom == -1.0_dp) THEN
649 nelec = real(mo_set%nelectron, dp)
650 ELSE
651 nelec = mo_set%n_el_f
652 END IF
653
654 mo_set%occupation_numbers(:) = 0.0_dp
655
656 CALL probe_occupancy(mo_set%occupation_numbers, mo_set%mu, mo_set%kTS, &
657 mo_set%eigenvalues, mo_set%mo_coeff, mo_set%maxocc, &
658 probe, n=nelec)
659 !NB: mu and T are taken from the hairy_probe type (defined in cp_control_types.F); these values are set in the input
660
661 ! Find the lowest fractional occupied MO (LFOMO)
662 DO imo = i_first, nmo
663 IF (mo_set%occupation_numbers(imo) < mo_set%maxocc) THEN
664 mo_set%lfomo = imo
665 EXIT
666 END IF
667 END DO
668 is_large = abs(maxval(mo_set%occupation_numbers) - mo_set%maxocc) > probe(1)%eps_hp
669 ! this is not a real problem, but the temperature might be a bit large
670 IF (is_large) THEN
671 cpwarn("Hair-probes occupancy distribution includes the first MO")
672 END IF
673
674 ! Find the highest (fractional) occupied MO which will be now the HOMO
675 DO imo = nmo, mo_set%lfomo, -1
676 IF (mo_set%occupation_numbers(imo) > probe(1)%eps_hp) THEN
677 mo_set%homo = imo
678 EXIT
679 END IF
680 END DO
681 is_large = abs(minval(mo_set%occupation_numbers)) > probe(1)%eps_hp
682 IF (is_large) THEN
683 CALL cp_warn(__location__, &
684 "Hair-probes occupancy distribution includes the last MO => "// &
685 "Add more MOs for proper smearing.")
686 END IF
687
688 ! check that the total electron count is accurate
689 is_large = (abs(nelec - accurate_sum(mo_set%occupation_numbers(:))) > probe(1)%eps_hp*nelec)
690 IF (is_large) THEN
691 cpwarn("Total number of electrons is not accurate")
692 END IF
693
694 END IF
695
696 ! Quick return, if no smearing information is supplied (TO BE FIXED, smear should become non-optional...)
697 IF (.NOT. PRESENT(smear)) THEN
698 ! there is no dependence of the energy on the eigenvalues
699 mo_set%uniform_occupation = .true.
700 IF (PRESENT(eval_deriv)) THEN
701 eval_deriv = 0.0_dp
702 END IF
703 CALL timestop(handle)
704 RETURN
705 END IF
706
707 ! Check if proper eigenvalues are already available
708 IF (smear%method /= smear_list) THEN
709 IF ((abs(mo_set%eigenvalues(1)) < 1.0e-12_dp) .AND. &
710 (abs(mo_set%eigenvalues(nmo)) < 1.0e-12_dp)) THEN
711 CALL timestop(handle)
712 RETURN
713 END IF
714 END IF
715
716 ! Perform smearing
717 IF (smear%do_smear) THEN
718 IF (PRESENT(xas_env)) THEN
719 i_first = xas_estate + 1
720 nelec = xas_nelectron
721 ELSE
722 i_first = 1
723 IF (smear%fixed_mag_mom == -1.0_dp) THEN
724 nelec = real(mo_set%nelectron, dp)
725 ELSE
726 nelec = mo_set%n_el_f
727 END IF
728 END IF
729 SELECT CASE (smear%method)
730 CASE (smear_fermi_dirac)
731 IF (.NOT. PRESENT(eval_deriv)) THEN
732 CALL smearfixed(mo_set%occupation_numbers(1:mo_set%nmo), mo_set%mu, mo_set%kTS, &
733 mo_set%eigenvalues(1:mo_set%nmo), nelec, &
734 smear%electronic_temperature, mo_set%maxocc, smear_fermi_dirac, &
735 xas_estate, occ_estate)
736 ELSE
737 IF (.NOT. ALLOCATED(tmp_v)) ALLOCATE (tmp_v(SIZE(eval_deriv)))
738 tmp_v(:) = eval_deriv - mo_set%eigenvalues + mo_set%mu
739 CALL smearfixedderivmv(eval_deriv, mo_set%occupation_numbers(1:mo_set%nmo), mo_set%mu, &
740 mo_set%kTS, mo_set%eigenvalues(1:mo_set%nmo), nelec, &
741 smear%electronic_temperature, mo_set%maxocc, smear_fermi_dirac, &
742 tmp_v, xas_estate, occ_estate)
743 END IF
744
745 ! Find the lowest fractional occupied MO (LFOMO)
746 DO imo = i_first, nmo
747 IF (mo_set%occupation_numbers(imo) < mo_set%maxocc) THEN
748 mo_set%lfomo = imo
749 EXIT
750 END IF
751 END DO
752 IF (i_first <= nmo) THEN
753 is_large = abs(mo_set%occupation_numbers(i_first) - mo_set%maxocc) > smear%eps_fermi_dirac
754 ELSE
755 is_large = .false.
756 END IF
757 ! this is not a real problem, but the temperature might be a bit large
758 cpwarn_if(is_large, "Fermi-Dirac smearing includes the first MO")
759
760 ! Find the highest (fractional) occupied MO which will be now the HOMO
761 DO imo = nmo, mo_set%lfomo, -1
762 IF (mo_set%occupation_numbers(imo) > smear%eps_fermi_dirac) THEN
763 mo_set%homo = imo
764 EXIT
765 END IF
766 END DO
767 is_large = abs(minval(mo_set%occupation_numbers)) > smear%eps_fermi_dirac
768 IF (is_large) THEN
769 CALL cp_warn(__location__, &
770 "Fermi-Dirac smearing includes the last MO => "// &
771 "Add more MOs for proper smearing.")
772 END IF
773
774 ! check that the total electron count is accurate
775 is_large = (abs(nelec - accurate_sum(mo_set%occupation_numbers(:))) > smear%eps_fermi_dirac*nelec)
776 cpwarn_if(is_large, "Total number of electrons is not accurate")
777
778 CASE (smear_gaussian, smear_mp, smear_mv)
779 IF (.NOT. PRESENT(eval_deriv)) THEN
780 CALL smearfixed(mo_set%occupation_numbers(1:mo_set%nmo), mo_set%mu, mo_set%kTS, &
781 mo_set%eigenvalues(1:mo_set%nmo), nelec, &
782 smear%smearing_width, mo_set%maxocc, smear%method, &
783 xas_estate, occ_estate)
784 ELSE
785 IF (.NOT. ALLOCATED(tmp_v)) ALLOCATE (tmp_v(SIZE(eval_deriv)))
786 tmp_v(:) = eval_deriv - mo_set%eigenvalues + mo_set%mu
787 CALL smearfixedderivmv(eval_deriv, mo_set%occupation_numbers(1:mo_set%nmo), mo_set%mu, &
788 mo_set%kTS, mo_set%eigenvalues(1:mo_set%nmo), nelec, &
789 smear%smearing_width, mo_set%maxocc, smear%method, &
790 tmp_v, xas_estate, occ_estate)
791 END IF
792
793 ! Method label for warnings
794 SELECT CASE (smear%method)
795 CASE (smear_gaussian)
796 method_label = "Gaussian"
797 CASE (smear_mp)
798 method_label = "Methfessel-Paxton"
799 CASE (smear_mv)
800 method_label = "Marzari-Vanderbilt"
801 END SELECT
802
803 ! Find the lowest fractional occupied MO (LFOMO)
804 DO imo = i_first, nmo
805 IF (abs(mo_set%occupation_numbers(imo) - mo_set%maxocc) > smear%eps_fermi_dirac) THEN
806 mo_set%lfomo = imo
807 EXIT
808 END IF
809 END DO
810 IF (i_first <= nmo) THEN
811 is_large = abs(mo_set%occupation_numbers(i_first) - mo_set%maxocc) > smear%eps_fermi_dirac
812 ELSE
813 is_large = .false.
814 END IF
815 cpwarn_if(is_large, trim(method_label)//" smearing includes the first MO")
816
817 ! Find the highest (fractional) occupied MO which will be now the HOMO
818 DO imo = nmo, mo_set%lfomo, -1
819 IF (abs(mo_set%occupation_numbers(imo)) > smear%eps_fermi_dirac) THEN
820 mo_set%homo = imo
821 EXIT
822 END IF
823 END DO
824 is_large = abs(mo_set%occupation_numbers(nmo)) > smear%eps_fermi_dirac
825 IF (is_large) THEN
826 CALL cp_warn(__location__, &
827 trim(method_label)//" smearing includes the last MO => "// &
828 "Add more MOs for proper smearing.")
829 END IF
830
831 ! Check that the total electron count is accurate
832 is_large = (abs(nelec - accurate_sum(mo_set%occupation_numbers(:))) > smear%eps_fermi_dirac*nelec)
833 cpwarn_if(is_large, "Total number of electrons is not accurate")
834
835 CASE (smear_energy_window)
836 ! not implemented
837 cpassert(.NOT. PRESENT(eval_deriv))
838
839 ! Define the energy window for the eigenvalues
840 e1 = mo_set%eigenvalues(mo_set%homo) - 0.5_dp*smear%window_size
841 IF (e1 <= mo_set%eigenvalues(1)) THEN
842 cpwarn("Energy window for smearing includes the first MO")
843 END IF
844
845 e2 = mo_set%eigenvalues(mo_set%homo) + 0.5_dp*smear%window_size
846 IF (e2 >= mo_set%eigenvalues(nmo)) THEN
847 CALL cp_warn(__location__, &
848 "Energy window for smearing includes the last MO => "// &
849 "Add more MOs for proper smearing.")
850 END IF
851
852 ! Find the lowest fractional occupied MO (LFOMO)
853 DO imo = i_first, nomo
854 IF (mo_set%eigenvalues(imo) > e1) THEN
855 mo_set%lfomo = imo
856 EXIT
857 END IF
858 END DO
859
860 ! Find the highest fractional occupied (non-zero) MO which will be the HOMO
861 DO imo = nmo, nomo, -1
862 IF (mo_set%eigenvalues(imo) < e2) THEN
863 mo_set%homo = imo
864 EXIT
865 END IF
866 END DO
867
868 ! Get the number of electrons to be smeared
869 edist = 0.0_dp
870 nelec = 0.0_dp
871
872 DO imo = mo_set%lfomo, mo_set%homo
873 nelec = nelec + mo_set%occupation_numbers(imo)
874 edist = edist + abs(e2 - mo_set%eigenvalues(imo))
875 END DO
876
877 ! Smear electrons inside the energy window
878 DO imo = mo_set%lfomo, mo_set%homo
879 edelta = abs(e2 - mo_set%eigenvalues(imo))
880 mo_set%occupation_numbers(imo) = min(mo_set%maxocc, nelec*edelta/edist)
881 nelec = nelec - mo_set%occupation_numbers(imo)
882 edist = edist - edelta
883 END DO
884
885 CASE (smear_list)
886 equal_size = SIZE(mo_set%occupation_numbers, 1) == SIZE(smear%list, 1)
887 cpassert(equal_size)
888 mo_set%occupation_numbers = smear%list
889 ! there is no dependence of the energy on the eigenvalues
890 IF (PRESENT(eval_deriv)) THEN
891 eval_deriv = 0.0_dp
892 END IF
893 ! most general case
894 mo_set%lfomo = 1
895 mo_set%homo = nmo
896 END SELECT
897
898 ! Check, if the smearing involves more than one MO
899 IF (mo_set%lfomo == mo_set%homo) THEN
900 mo_set%homo = nomo
901 mo_set%lfomo = nomo + 1
902 ELSE
903 mo_set%uniform_occupation = .false.
904 END IF
905
906 END IF ! do smear
907
908 ! zeros don't count as uniform
909 mo_set%uniform_occupation = has_uniform_occupation(mo_set=mo_set)
910
911 IF (ALLOCATED(tmp_v)) DEALLOCATE (tmp_v)
912 CALL timestop(handle)
913
914 END SUBROUTINE set_mo_occupation_1
915
916END MODULE qs_mo_occupation
modulo
static GRID_HOST_DEVICE int modulo(int a, int m)
Equivalent of Fortran's MODULO, which always return a positive number. https://gcc....
Definition grid_common.h:125
cp_log_handling::cp_to_string
Definition cp_log_handling.F:90
kahan_sum::accurate_sum
Definition kahan_sum.F:41
qs_mo_occupation::set_mo_occupation
Definition qs_mo_occupation.F:50
cp_control_types
Defines control structures, which contain the parameters and the settings for the DFT-based calculati...
Definition cp_control_types.F:12
cp_log_handling
various routines to log and control the output. The idea is that decisions about where to log should ...
Definition cp_log_handling.F:41
hairy_probes
Definition hairy_probes.F:8
hairy_probes::probe_occupancy
subroutine, public probe_occupancy(occ, fermi, kts, energies, coeff, maxocc, probe, n)
subroutine to calculate occupation number and 'Fermi' level using the
Definition hairy_probes.F:52
input_constants
collects all constants needed in input so that they can be used without circular dependencies
Definition input_constants.F:18
input_constants::smear_fermi_dirac
integer, parameter, public smear_fermi_dirac
Definition input_constants.F:928
input_constants::smear_energy_window
integer, parameter, public smear_energy_window
Definition input_constants.F:928
input_constants::smear_list
integer, parameter, public smear_list
Definition input_constants.F:928
input_constants::smear_gaussian
integer, parameter, public smear_gaussian
Definition input_constants.F:928
input_constants::smear_mv
integer, parameter, public smear_mv
Definition input_constants.F:928
input_constants::smear_mp
integer, parameter, public smear_mp
Definition input_constants.F:928
kahan_sum
sums arrays of real/complex numbers with much reduced round-off as compared to a naive implementation...
Definition kahan_sum.F:29
kinds
Defines the basic variable types.
Definition kinds.F:23
kinds::dp
integer, parameter, public dp
Definition kinds.F:34
qs_mo_occupation
Set occupation of molecular orbitals.
Definition qs_mo_occupation.F:15
qs_mo_types
Definition and initialisation of the mo data type.
Definition qs_mo_types.F:22
qs_mo_types::set_mo_set
subroutine, public set_mo_set(mo_set, maxocc, homo, lfomo, nao, nelectron, n_el_f, nmo, eigenvalues, occupation_numbers, uniform_occupation, kts, mu, flexible_electron_count)
Set the components of a MO set data structure.
Definition qs_mo_types.F:456
qs_mo_types::has_uniform_occupation
logical function, public has_uniform_occupation(mo_set, first_mo, last_mo, occupation, tolerance)
Check if the set of MOs in mo_set specifed by the MO index range [first_mo,last_mo] an integer occupa...
Definition qs_mo_types.F:507
qs_mo_types::get_mo_set
subroutine, public get_mo_set(mo_set, maxocc, homo, lfomo, nao, nelectron, n_el_f, nmo, eigenvalues, occupation_numbers, mo_coeff, mo_coeff_b, uniform_occupation, kts, mu, flexible_electron_count)
Get the components of a MO set data structure.
Definition qs_mo_types.F:401
scf_control_types
parameters that control an scf iteration
Definition scf_control_types.F:17
smearing_utils
Unified smearing module supporting four methods: smear_fermi_dirac — Fermi-Dirac distribution smear_g...
Definition smearing_utils.F:24
smearing_utils::smearocc
subroutine, public smearocc(f, n, kts, e, mu, sigma, maxocc, method, estate, festate)
Returns occupations and smearing correction for a given set of energies and chemical potential,...
Definition smearing_utils.F:107
smearing_utils::smearfixed
subroutine, public smearfixed(f, mu, kts, e, n, sigma, maxocc, method, estate, festate)
Bisection search for the chemical potential mu such that the total electron count equals N,...
Definition smearing_utils.F:314
smearing_utils::smearfixedderivmv
subroutine, public smearfixedderivmv(result, f, mu, kts, e, n_el, sigma, maxocc, method, v, estate, festate)
Apply TRANSPOSE(df/de) to a vector WITHOUT forming the full N x N Jacobian. O(N) time and O(N) memory...
Definition smearing_utils.F:959
util
All kind of helpful little routines.
Definition util.F:14
xas_env_types
define create destroy get and put information in xas_env to calculate the x-ray absorption spectra
Definition xas_env_types.F:15
xas_env_types::get_xas_env
subroutine, public get_xas_env(xas_env, exc_state, nao, nvirtual, nvirtual2, centers_wfn, atom_of_state, exc_atoms, nexc_states, type_of_state, mykind_of_atom, mykind_of_kind, state_of_atom, spectrum, groundstate_coeff, ostrength_sm, dip_fm_set, excvec_coeff, excvec_overlap, unoccupied_orbs, unoccupied_evals, unoccupied_max_iter, unoccupied_eps, all_vectors, all_evals, my_gto_basis, qs_loc_env, stogto_overlap, occ_estate, xas_nelectron, xas_estate, nexc_atoms, nexc_search, spin_channel, scf_env, scf_control)
...
Definition xas_env_types.F:154
cp_control_types::hairy_probes_type
Definition cp_control_types.F:48
qs_mo_types::mo_set_type
Definition qs_mo_types.F:47
scf_control_types::gce_type
Definition scf_control_types.F:150
scf_control_types::smear_type
contains the parameters needed by a scf run
Definition scf_control_types.F:92
xas_env_types::xas_environment_type
Definition xas_env_types.F:69