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 function that build the kpoints section of the input
10 : !> \par History
11 : !> init [07.2014]
12 : !> \author JGH
13 : ! **************************************************************************************************
14 : MODULE 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 :
50 : CONTAINS
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 30282 : SUBROUTINE create_kpoints_section(section)
74 : TYPE(section_type), POINTER :: section
75 :
76 : TYPE(keyword_type), POINTER :: keyword
77 :
78 30282 : CPASSERT(.NOT. ASSOCIATED(section))
79 : CALL section_create(section, __LOCATION__, name="KPOINTS", &
80 : description="Controls Brillouin-zone sampling with k-points.", &
81 30282 : n_keywords=1, n_subsections=0, repeats=.FALSE.)
82 :
83 30282 : 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 90846 : n_var=-1, type_of_var=char_t)
100 30282 : CALL section_add_keyword(section, keyword)
101 30282 : 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 30282 : default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
111 30282 : CALL section_add_keyword(section, keyword)
112 30282 : 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 30282 : n_var=4, type_of_var=real_t)
118 30282 : CALL section_add_keyword(section, keyword)
119 30282 : 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 30282 : usage="UNITS <value>", type_of_var=char_t, default_c_val="B_VECTOR")
128 30282 : CALL section_add_keyword(section, keyword)
129 30282 : 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 30282 : default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
135 30282 : CALL section_add_keyword(section, keyword)
136 30282 : 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 30282 : default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
142 30282 : CALL section_add_keyword(section, keyword)
143 30282 : 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 30282 : default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
150 30282 : CALL section_add_keyword(section, keyword)
151 30282 : 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 30282 : default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
160 30282 : CALL section_add_keyword(section, keyword)
161 30282 : 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 30282 : default_i_val=use_k290_kpoint_backend)
176 30282 : CALL section_add_keyword(section, keyword)
177 30282 : 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 30282 : default_i_val=use_k290_kpoint_symmetry)
193 30282 : CALL section_add_keyword(section, keyword)
194 30282 : CALL keyword_release(keyword)
195 :
196 : CALL keyword_create(keyword, __LOCATION__, name="VERBOSE", &
197 : description="Verbose output information.", &
198 : usage="VERBOSE <LOGICAL>", &
199 30282 : default_l_val=.FALSE., lone_keyword_l_val=.TRUE.)
200 30282 : CALL section_add_keyword(section, keyword)
201 30282 : 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 60564 : default_r_val=1.0e-6_dp)
208 30282 : CALL section_add_keyword(section, keyword)
209 30282 : 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 30282 : default_i_val=-1)
220 30282 : CALL section_add_keyword(section, keyword)
221 30282 : 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 30282 : enum_i_vals=[use_real_wfn, use_complex_wfn])
234 30282 : CALL section_add_keyword(section, keyword)
235 30282 : CALL keyword_release(keyword)
236 :
237 30282 : END SUBROUTINE create_kpoints_section
238 :
239 : ! **************************************************************************************************
240 : !> \brief ...
241 : !> \param section ...
242 : !> \param section_name ...
243 : !> \author JGH
244 : ! **************************************************************************************************
245 121048 : 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 121048 : IF (PRESENT(section_name)) THEN
253 10078 : my_section_name = section_name
254 : ELSE
255 110970 : my_section_name = "KPOINT_SET"
256 : END IF
257 :
258 121048 : 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 121048 : n_keywords=0, n_subsections=0, repeats=.TRUE.)
262 : ! keywords
263 121048 : NULLIFY (keyword)
264 : CALL keyword_create(keyword, __LOCATION__, name="SPECIAL_POINT", &
265 : description="Name and coordinates of a special k-point", &
266 121048 : usage="SPECIAL_POINT GAMMA 0.0 0.0 0.0", n_var=-1, type_of_var=char_t, repeats=.TRUE.)
267 121048 : CALL section_add_keyword(section, keyword)
268 121048 : CALL keyword_release(keyword)
269 : !
270 : CALL keyword_create(keyword, __LOCATION__, name="NPOINTS", &
271 : description="Number of k-points along the line.", &
272 121048 : default_i_val=0)
273 121048 : CALL section_add_keyword(section, keyword)
274 121048 : 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 121048 : usage="UNITS <value>", type_of_var=char_t, default_c_val="B_VECTOR")
283 121048 : CALL section_add_keyword(section, keyword)
284 121048 : CALL keyword_release(keyword)
285 :
286 121048 : END SUBROUTINE create_kpoint_set_section
287 :
288 : END MODULE input_cp2k_kpoints
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