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input_cp2k_kpoints.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 function that build the kpoints section of the input
10!> \par History
11!> init [07.2014]
12!> \author JGH
13! **************************************************************************************************
14MODULE input_cp2k_kpoints
15 USE bibliography, ONLY: macdonald1978,&
16 monkhorst1976
17 USE input_keyword_types, ONLY: keyword_create,&
18 keyword_release,&
19 keyword_type
20 USE input_section_types, ONLY: section_add_keyword,&
21 section_create,&
22 section_type
23 USE input_val_types, ONLY: char_t,&
24 enum_t,&
25 real_t
26 USE kinds, ONLY: default_path_length,&
27 dp
28 USE string_utilities, ONLY: newline,&
29 s2a
30#include "./base/base_uses.f90"
31
32 IMPLICIT NONE
33 PRIVATE
34
35 CHARACTER(len=*), PARAMETER, PRIVATE :: moduleN = 'input_cp2k_kpoints'
36
37 INTEGER, PARAMETER :: use_real_wfn = 101, &
38 use_complex_wfn = 100, &
39 use_k290_kpoint_symmetry = 200, &
40 use_spglib_kpoint_symmetry = 201, &
41 use_k290_kpoint_backend = 300, &
42 use_spglib_kpoint_backend = 301
43
44 PUBLIC :: create_kpoints_section
45 PUBLIC :: create_kpoint_set_section
46 PUBLIC :: use_real_wfn, use_complex_wfn
47 PUBLIC :: use_k290_kpoint_symmetry, use_spglib_kpoint_symmetry
48 PUBLIC :: use_k290_kpoint_backend, use_spglib_kpoint_backend
49
50CONTAINS
51
52! **************************************************************************************************
53!> \brief Creates the Kpoints section
54!> SECTION: &kpoint... &end
55!> SCHEME [None, Gamma, Monkhorst-Pack, MacDonald, General]
56!> { nx ny nz }
57!> { nx ny nz sx sy sz }
58!> KPOINT x1 y1 z1 w1
59!> SYMMETRY [on, off]
60!> WAVEFUNCTION [real, complex]
61!> FULL_GRID [on, off]
62!> INVERSION_SYMMETRY_ONLY [on, off]
63!> DEBUG_FULL_KPOINT_SYMMETRY [on, off]
64!> SYMMETRY_BACKEND [K290, SPGLIB]
65!> SYMMETRY_REDUCTION_METHOD [K290, SPGLIB]
66!> VERBOSE [on, off]
67!> EPS_SYMMETRY value
68!> PARALLEL_GROUP_SIZE [-1,0,n]
69!>
70!> \param section the section to create
71!> \author JGH
72! **************************************************************************************************
73 SUBROUTINE create_kpoints_section(section)
74 TYPE(section_type), POINTER :: section
75
76 TYPE(keyword_type), POINTER :: keyword
77
78 cpassert(.NOT. ASSOCIATED(section))
79 CALL section_create(section, __location__, name="KPOINTS", &
80 description="Controls Brillouin-zone sampling with k-points.", &
81 n_keywords=1, n_subsections=0, repeats=.false.)
82
83 NULLIFY (keyword)
84 CALL keyword_create(keyword, __location__, name="SCHEME", &
85 description="K-point generation scheme. Available options are:"//newline// &
86 "- `NONE`"//newline// &
87 "- `GAMMA`"//newline// &
88 "- `MONKHORST-PACK`"//newline// &
89 "- `MACDONALD`"//newline// &
90 "- `GENERAL`"//newline// &
91 newline// &
92 "For `MONKHORST-PACK` the number of k points in all 3 dimensions has to"// &
93 " be supplied along with the keyword. For `MACDONALD` also the list of shifts."// &
94 " E.g. `MONKHORST-PACK 12 12 8`, `MACDONALD 4 4 4 0.25 0.25 0.25`."// &
95 " `GENERAL` uses explicitly listed k-points. If symmetry reduction is requested,"// &
96 " the explicit set must be equally weighted and closed under the selected operations.", &
97 usage="SCHEME {KPMETHOD} {integer} {integer} ..", &
98 citations=[monkhorst1976, macdonald1978], &
99 n_var=-1, type_of_var=char_t)
100 CALL section_add_keyword(section, keyword)
101 CALL keyword_release(keyword)
102
103 CALL keyword_create(keyword, __location__, name="GAMMA_CENTERED", &
104 description="Generate a gamma-centered variant of the "// &
105 "Monkhorst-Pack or MacDonald mesh. This shifts the original mesh so "// &
106 "it can include the Gamma point, and makes sense only when an "// &
107 "even number of subdivisions is used. For MacDonald meshes, the "// &
108 "explicit shift is applied after the gamma-centering shift.", &
109 usage="GAMMA_CENTERED <LOGICAL>", &
110 default_l_val=.false., lone_keyword_l_val=.true.)
111 CALL section_add_keyword(section, keyword)
112 CALL keyword_release(keyword)
113
114 CALL keyword_create(keyword, __location__, name="KPOINT", &
115 description="Specify kpoint coordinates and weight. ", &
116 usage="KPOINT x y z w", repeats=.true., &
117 n_var=4, type_of_var=real_t)
118 CALL section_add_keyword(section, keyword)
119 CALL keyword_release(keyword)
120
121 CALL keyword_create(keyword, __location__, name="UNITS", &
122 description="Special k-points are defined either in units"// &
123 " of reciprocal lattice vectors or in Cartesian coordinates in units of 2Pi/len."// &
124 " B_VECTOR: in multiples of the reciprocal lattice vectors (b)."// &
125 " CART_ANGSTROM: In units of 2*Pi/Angstrom."// &
126 " CART_BOHR: In units of 2*Pi/Bohr.", &
127 usage="UNITS <value>", type_of_var=char_t, default_c_val="B_VECTOR")
128 CALL section_add_keyword(section, keyword)
129 CALL keyword_release(keyword)
130
131 CALL keyword_create(keyword, __location__, name="SYMMETRY", &
132 description="Use symmetry to reduce the number of kpoints.", &
133 usage="SYMMETRY <LOGICAL>", &
134 default_l_val=.false., lone_keyword_l_val=.true.)
135 CALL section_add_keyword(section, keyword)
136 CALL keyword_release(keyword)
137
138 CALL keyword_create(keyword, __location__, name="FULL_GRID", &
139 description="Use the full, non-symmetry-reduced k-point grid.", &
140 usage="FULL_GRID <LOGICAL>", &
141 default_l_val=.false., lone_keyword_l_val=.true.)
142 CALL section_add_keyword(section, keyword)
143 CALL keyword_release(keyword)
144
145 CALL keyword_create(keyword, __location__, name="INVERSION_SYMMETRY_ONLY", &
146 description="Restrict k-point reduction to k-space inversion "// &
147 "(time-reversal) symmetry.", &
148 usage="INVERSION_SYMMETRY_ONLY <LOGICAL>", &
149 default_l_val=.false., lone_keyword_l_val=.true.)
150 CALL section_add_keyword(section, keyword)
151 CALL keyword_release(keyword)
152
153 CALL keyword_create(keyword, __location__, name="DEBUG_FULL_KPOINT_SYMMETRY", &
154 description="Use full atomic k-point symmetry also for DEBUG finite-difference "// &
155 "points. This is an expert option: the default keeps finite-difference energies "// &
156 "on inversion/time-reversal symmetry to avoid comparing slightly different "// &
157 "irreducible k-point sets.", &
158 usage="DEBUG_FULL_KPOINT_SYMMETRY <LOGICAL>", &
159 default_l_val=.false., lone_keyword_l_val=.true.)
160 CALL section_add_keyword(section, keyword)
161 CALL keyword_release(keyword)
162
163 CALL keyword_create(keyword, __location__, name="SYMMETRY_BACKEND", &
164 description="Select the backend used to provide and apply atomic "// &
165 "k-point symmetry operations. K290 is the established default. "// &
166 "SPGLIB uses the symmetry operations returned by SPGLIB, including "// &
167 "their fractional translations. This applies to Monkhorst-Pack, MacDonald, and "// &
168 "closed GENERAL k-point sets. If "// &
169 "SYMMETRY_REDUCTION_METHOD is not specified, it follows the selected backend.", &
170 usage="SYMMETRY_BACKEND K290", type_of_var=enum_t, &
171 enum_c_vals=s2a("K290", "SPGLIB"), &
172 enum_i_vals=[use_k290_kpoint_backend, use_spglib_kpoint_backend], &
173 enum_desc=s2a("Use the existing K290 k-point symmetry backend.", &
174 "Use SPGLIB symmetry operations as k-point symmetry backend."), &
175 default_i_val=use_k290_kpoint_backend)
176 CALL section_add_keyword(section, keyword)
177 CALL keyword_release(keyword)
178
179 CALL keyword_create(keyword, __location__, name="SYMMETRY_REDUCTION_METHOD", &
180 description="Select the method used to reduce Monkhorst-Pack and MacDonald "// &
181 "k-point meshes when atomic symmetry is enabled. K290 is the established "// &
182 "default. SPGLIB uses the symmetry operations returned by SPGLIB for the "// &
183 "k-point reduction. GENERAL k-point lists can be reduced when the explicit set is "// &
184 "equally weighted and closed under the selected operations. With "// &
185 "SYMMETRY_BACKEND K290 this can be used as a comparison mode using K290 "// &
186 "operations for SPGLIB-generated mappings.", &
187 usage="SYMMETRY_REDUCTION_METHOD K290", type_of_var=enum_t, &
188 enum_c_vals=s2a("K290", "SPGLIB"), &
189 enum_i_vals=[use_k290_kpoint_symmetry, use_spglib_kpoint_symmetry], &
190 enum_desc=s2a("Use the existing K290 k-point symmetry reduction method.", &
191 "Use SPGLIB symmetry operations for k-point reduction."), &
192 default_i_val=use_k290_kpoint_symmetry)
193 CALL section_add_keyword(section, keyword)
194 CALL keyword_release(keyword)
195
196 CALL keyword_create(keyword, __location__, name="VERBOSE", &
197 description="Verbose output information.", &
198 usage="VERBOSE <LOGICAL>", &
199 default_l_val=.false., lone_keyword_l_val=.true.)
200 CALL section_add_keyword(section, keyword)
201 CALL keyword_release(keyword)
202
203 CALL keyword_create(keyword, __location__, name="EPS_SYMMETRY", variants=["EPS_GEO"], &
204 description="Accuracy in k-point symmetry determination."//newline// &
205 "EPS_GEO is accepted as an alias.", &
206 usage="EPS_SYMMETRY <real>", &
207 default_r_val=1.0e-6_dp)
208 CALL section_add_keyword(section, keyword)
209 CALL keyword_release(keyword)
210
211 CALL keyword_create(keyword, __location__, name="PARALLEL_GROUP_SIZE", &
212 description="Number of MPI processes to be used for a single k-point."// &
213 " This number must divide the total number of processes."// &
214 " The number of groups must divide the total number of kpoints."// &
215 " Value=-1 (smallest possible number of processes per group, satisfying the constraints)."// &
216 " Value=0 (all processes)."// &
217 " Value=n (exactly n processes).", &
218 usage="PARALLEL_GROUP_SIZE <integer>", &
219 default_i_val=-1)
220 CALL section_add_keyword(section, keyword)
221 CALL keyword_release(keyword)
222
223 CALL keyword_create(keyword, __location__, name="WAVEFUNCTIONS", &
224 description="Select whether real or complex wavefunctions should be used "// &
225 "when allowed by the k-point set. REAL wavefunctions can only represent "// &
226 "Gamma or special k-points and symmetry operations with real Bloch phases. "// &
227 "Use COMPLEX for general atomic k-point symmetries with nontrivial phases.", &
228 usage="WAVEFUNCTIONS REAL", &
229 default_i_val=use_complex_wfn, &
230 enum_c_vals=s2a("REAL", "COMPLEX"), &
231 enum_desc=s2a("Use real wavefunctions (if possible by kpoints specified).", &
232 "Use complex wavefunctions (default)."), &
233 enum_i_vals=[use_real_wfn, use_complex_wfn])
234 CALL section_add_keyword(section, keyword)
235 CALL keyword_release(keyword)
236
237 END SUBROUTINE create_kpoints_section
238
239! **************************************************************************************************
240!> \brief ...
241!> \param section ...
242!> \param section_name ...
243!> \author JGH
244! **************************************************************************************************
245 SUBROUTINE create_kpoint_set_section(section, section_name)
246 TYPE(section_type), POINTER :: section
247 CHARACTER(LEN=*), OPTIONAL :: section_name
248
249 CHARACTER(len=default_path_length) :: my_section_name
250 TYPE(keyword_type), POINTER :: keyword
251
252 IF (PRESENT(section_name)) THEN
253 my_section_name = section_name
254 ELSE
255 my_section_name = "KPOINT_SET"
256 END IF
257
258 cpassert(.NOT. ASSOCIATED(section))
259 CALL section_create(section, __location__, name=my_section_name, &
260 description="Specifies a k-point line to be calculated.", &
261 n_keywords=0, n_subsections=0, repeats=.true.)
262 ! keywords
263 NULLIFY (keyword)
264 CALL keyword_create(keyword, __location__, name="SPECIAL_POINT", &
265 description="Name and coordinates of a special k-point", &
266 usage="SPECIAL_POINT GAMMA 0.0 0.0 0.0", n_var=-1, type_of_var=char_t, repeats=.true.)
267 CALL section_add_keyword(section, keyword)
268 CALL keyword_release(keyword)
269 !
270 CALL keyword_create(keyword, __location__, name="NPOINTS", &
271 description="Number of k-points along the line.", &
272 default_i_val=0)
273 CALL section_add_keyword(section, keyword)
274 CALL keyword_release(keyword)
275 !
276 CALL keyword_create(keyword, __location__, name="UNITS", &
277 description="Special k-points are defined either in units"// &
278 " of reciprocal lattice vectors or in Cartesian coordinates in units of 2Pi/len."// &
279 " B_VECTOR: in multiples of the reciprocal lattice vectors (b)."// &
280 " CART_ANGSTROM: In units of 2*Pi/Angstrom."// &
281 " CART_BOHR: In units of 2*Pi/Bohr.", &
282 usage="UNITS <value>", type_of_var=char_t, default_c_val="B_VECTOR")
283 CALL section_add_keyword(section, keyword)
284 CALL keyword_release(keyword)
285
286 END SUBROUTINE create_kpoint_set_section
287
288END MODULE input_cp2k_kpoints
string_utilities::s2a
Definition string_utilities.F:49
bibliography
collects all references to literature in CP2K as new algorithms / method are included from literature...
Definition bibliography.F:21
bibliography::monkhorst1976
integer, save, public monkhorst1976
Definition bibliography.F:36
bibliography::macdonald1978
integer, save, public macdonald1978
Definition bibliography.F:36
input_cp2k_kpoints
function that build the kpoints section of the input
Definition input_cp2k_kpoints.F:14
input_cp2k_kpoints::use_spglib_kpoint_symmetry
integer, parameter, public use_spglib_kpoint_symmetry
Definition input_cp2k_kpoints.F:37
input_cp2k_kpoints::use_k290_kpoint_symmetry
integer, parameter, public use_k290_kpoint_symmetry
Definition input_cp2k_kpoints.F:37
input_cp2k_kpoints::create_kpoints_section
subroutine, public create_kpoints_section(section)
Creates the Kpoints section SECTION: &kpoint... &end SCHEME [None, Gamma, Monkhorst-Pack,...
Definition input_cp2k_kpoints.F:74
input_cp2k_kpoints::use_real_wfn
integer, parameter, public use_real_wfn
Definition input_cp2k_kpoints.F:37
input_cp2k_kpoints::create_kpoint_set_section
subroutine, public create_kpoint_set_section(section, section_name)
...
Definition input_cp2k_kpoints.F:246
input_cp2k_kpoints::use_spglib_kpoint_backend
integer, parameter, public use_spglib_kpoint_backend
Definition input_cp2k_kpoints.F:37
input_cp2k_kpoints::use_k290_kpoint_backend
integer, parameter, public use_k290_kpoint_backend
Definition input_cp2k_kpoints.F:37
input_cp2k_kpoints::use_complex_wfn
integer, parameter, public use_complex_wfn
Definition input_cp2k_kpoints.F:37
input_keyword_types
represents keywords in an input
Definition input_keyword_types.F:14
input_keyword_types::keyword_release
subroutine, public keyword_release(keyword)
releases the given keyword (see doc/ReferenceCounting.html)
Definition input_keyword_types.F:440
input_keyword_types::keyword_create
subroutine, public keyword_create(keyword, location, name, description, usage, type_of_var, n_var, repeats, variants, default_val, default_l_val, default_r_val, default_lc_val, default_c_val, default_i_val, default_l_vals, default_r_vals, default_c_vals, default_i_vals, lone_keyword_val, lone_keyword_l_val, lone_keyword_r_val, lone_keyword_c_val, lone_keyword_i_val, lone_keyword_l_vals, lone_keyword_r_vals, lone_keyword_c_vals, lone_keyword_i_vals, enum_c_vals, enum_i_vals, enum, enum_strict, enum_desc, unit_str, citations, deprecation_notice, removed)
creates a keyword object
Definition input_keyword_types.F:156
input_section_types
objects that represent the structure of input sections and the data contained in an input section
Definition input_section_types.F:15
input_section_types::section_create
subroutine, public section_create(section, location, name, description, n_keywords, n_subsections, repeats, citations, deprecation_notice)
creates a list of keywords
Definition input_section_types.F:158
input_section_types::section_add_keyword
subroutine, public section_add_keyword(section, keyword)
adds a keyword to the given section
Definition input_section_types.F:511
input_val_types
a wrapper for basic fortran types.
Definition input_val_types.F:14
input_val_types::real_t
integer, parameter, public real_t
Definition input_val_types.F:41
input_val_types::char_t
integer, parameter, public char_t
Definition input_val_types.F:41
input_val_types::enum_t
integer, parameter, public enum_t
Definition input_val_types.F:41
kinds
Defines the basic variable types.
Definition kinds.F:23
kinds::dp
integer, parameter, public dp
Definition kinds.F:34
kinds::default_path_length
integer, parameter, public default_path_length
Definition kinds.F:58
string_utilities
Utilities for string manipulations.
Definition string_utilities.F:16
string_utilities::newline
character(len=1), parameter, public newline
Definition string_utilities.F:29
input_keyword_types::keyword_type
represent a keyword in the input
Definition input_keyword_types.F:89
input_section_types::section_type
represent a section of the input file
Definition input_section_types.F:102