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input_cp2k_negf.F
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1!--------------------------------------------------------------------------------------------------!
2! CP2K: A general program to perform molecular dynamics simulations !
3! Copyright 2000-2024 CP2K developers group <https://cp2k.org> !
4! !
5! SPDX-License-Identifier: GPL-2.0-or-later !
6!--------------------------------------------------------------------------------------------------!
7
8! **************************************************************************************************
9!> \brief Input section for NEGF based quantum transport calculations.
10! **************************************************************************************************
11
12MODULE input_cp2k_negf
13 USE bibliography, ONLY: bailey2006,&
14 papior2017
15 USE cp_output_handling, ONLY: cp_print_key_section_create,&
16 debug_print_level,&
17 high_print_level,&
18 low_print_level,&
19 medium_print_level,&
20 silent_print_level
21 USE input_constants, ONLY: negfint_method_cc,&
22 negfint_method_simpson
23 USE input_keyword_types, ONLY: keyword_create,&
24 keyword_release,&
25 keyword_type
26 USE input_section_types, ONLY: section_add_keyword,&
27 section_add_subsection,&
28 section_create,&
29 section_release,&
30 section_type
31 USE input_val_types, ONLY: char_t,&
32 integer_t,&
33 real_t
34 USE kinds, ONLY: dp
35 USE physcon, ONLY: kelvin
36 USE qs_density_mixing_types, ONLY: create_mixing_section
37 USE string_utilities, ONLY: s2a
38#include "./base/base_uses.f90"
39
40 IMPLICIT NONE
41 PRIVATE
42
43 CHARACTER(len=*), PARAMETER, PRIVATE :: moduleN = 'input_cp2k_negf'
44
45 PUBLIC :: create_negf_section
46
47CONTAINS
48
49! **************************************************************************************************
50!> \brief Create NEGF input section.
51!> \param section input section
52!> \par History
53!> * 02.2017 created [Sergey Chulkov]
54! **************************************************************************************************
55 SUBROUTINE create_negf_section(section)
56 TYPE(section_type), POINTER :: section
57
58 TYPE(keyword_type), POINTER :: keyword
59 TYPE(section_type), POINTER :: print_key, subsection
60
61 cpassert(.NOT. ASSOCIATED(section))
62 CALL section_create(section, __location__, name="NEGF", &
63 description="Parameters which control quantum transport calculation"// &
64 " based on Non-Equilibrium Green's Function method.", &
65 citations=(/bailey2006, papior2017/), &
66 n_keywords=18, n_subsections=6, repeats=.false.)
67
68 NULLIFY (keyword, print_key, subsection)
69
70 CALL create_contact_section(subsection)
71 CALL section_add_subsection(section, subsection)
72 CALL section_release(subsection)
73
74 CALL create_atomlist_section(subsection, "SCATTERING_REGION", "Defines atoms which form the scattering region.", .false.)
75 CALL section_add_subsection(section, subsection)
76 CALL section_release(subsection)
77
78 ! mixing section
79 CALL create_mixing_section(subsection, ls_scf=.false.)
80 CALL section_add_subsection(section, subsection)
81 CALL section_release(subsection)
82
83 CALL keyword_create(keyword, __location__, name="DISABLE_CACHE", &
84 description="Do not keep contact self-energy matrices for future reuse", &
85 default_l_val=.false., lone_keyword_l_val=.true.)
86 CALL section_add_keyword(section, keyword)
87 CALL keyword_release(keyword)
88
89 ! convergence thresholds
90 CALL keyword_create(keyword, __location__, name="EPS_DENSITY", &
91 description="Target accuracy for electronic density.", &
92 n_var=1, type_of_var=real_t, default_r_val=1.0e-5_dp)
93 CALL section_add_keyword(section, keyword)
94 CALL keyword_release(keyword)
95
96 CALL keyword_create(keyword, __location__, name="EPS_GREEN", &
97 description="Target accuracy for surface Green's functions.", &
98 n_var=1, type_of_var=real_t, default_r_val=1.0e-5_dp)
99 CALL section_add_keyword(section, keyword)
100 CALL keyword_release(keyword)
101
102 CALL keyword_create(keyword, __location__, name="EPS_SCF", &
103 description="Target accuracy for SCF convergence.", &
104 n_var=1, type_of_var=real_t, default_r_val=1.0e-5_dp)
105 CALL section_add_keyword(section, keyword)
106 CALL keyword_release(keyword)
107
108 CALL keyword_create(keyword, __location__, name="EPS_GEO", &
109 description="Accuracy in mapping atoms between different force environments.", &
110 n_var=1, type_of_var=real_t, unit_str="angstrom", &
111 default_r_val=1.0e-6_dp)
112 CALL section_add_keyword(section, keyword)
113 CALL keyword_release(keyword)
114
115 CALL keyword_create(keyword, __location__, name="ENERGY_LBOUND", &
116 description="Lower bound energy of the conductance band.", &
117 n_var=1, type_of_var=real_t, unit_str="hartree", &
118 default_r_val=-5.0_dp)
119 CALL section_add_keyword(section, keyword)
120 CALL keyword_release(keyword)
121
122 CALL keyword_create(keyword, __location__, name="ETA", &
123 description="Infinitesimal offset from the real axis.", &
124 n_var=1, type_of_var=real_t, unit_str="hartree", &
125 default_r_val=1.0e-5_dp)
126 CALL section_add_keyword(section, keyword)
127 CALL keyword_release(keyword)
128
129 CALL keyword_create(keyword, __location__, name="HOMO_LUMO_GAP", &
130 description="The gap between the HOMO and some fictitious LUMO. This option is used as"// &
131 " an initial offset to determine the actual Fermi level of bulk contacts."// &
132 " It does not need to be exact HOMO-LUMO gap, just some value to start with.", &
133 n_var=1, type_of_var=real_t, unit_str="hartree", &
134 default_r_val=0.2_dp)
135 CALL section_add_keyword(section, keyword)
136 CALL keyword_release(keyword)
137
138 CALL keyword_create(keyword, __location__, name="DELTA_NPOLES", &
139 description="Number of poles of Fermi function to consider.", &
140 n_var=1, type_of_var=integer_t, &
141 default_i_val=4)
142 CALL section_add_keyword(section, keyword)
143 CALL keyword_release(keyword)
144
145 CALL keyword_create(keyword, __location__, name="GAMMA_KT", &
146 description="Offset from the axis (in terms of k*T)"// &
147 " where poles of the Fermi function reside.", &
148 n_var=1, type_of_var=integer_t, &
149 default_i_val=20)
150 CALL section_add_keyword(section, keyword)
151 CALL keyword_release(keyword)
152
153 CALL keyword_create(keyword, __location__, name="INTEGRATION_METHOD", &
154 description="Method to integrate Green's functions along a closed-circuit contour.", &
155 default_i_val=negfint_method_cc, &
156 enum_c_vals=s2a("CLENSHAW-CURTIS", "SIMPSON"), &
157 enum_desc=s2a( &
158 "Adaptive Clenshaw-Curtis quadrature method. Requires FFTW3 library.", &
159 "Adaptive Simpson method. Works without FFTW3."), &
160 enum_i_vals=(/negfint_method_cc, negfint_method_simpson/))
161 CALL section_add_keyword(section, keyword)
162 CALL keyword_release(keyword)
163
164 CALL keyword_create(keyword, __location__, name="INTEGRATION_MIN_POINTS", &
165 description="Initial (minimal) number of grid point for adaptive numerical integration.", &
166 n_var=1, type_of_var=integer_t, &
167 default_i_val=16)
168 CALL section_add_keyword(section, keyword)
169 CALL keyword_release(keyword)
170
171 CALL keyword_create(keyword, __location__, name="INTEGRATION_MAX_POINTS", &
172 description="Maximal number of grid point for adaptive numerical integration.", &
173 n_var=1, type_of_var=integer_t, &
174 default_i_val=512)
175 CALL section_add_keyword(section, keyword)
176 CALL keyword_release(keyword)
177
178 CALL keyword_create(keyword, __location__, name="MAX_SCF", &
179 description="Maximum number of SCF iterations to be performed.", &
180 n_var=1, type_of_var=integer_t, &
181 default_i_val=30)
182 CALL section_add_keyword(section, keyword)
183 CALL keyword_release(keyword)
184
185 CALL keyword_create(keyword, __location__, name="NPROC_POINT", &
186 description="Number of MPI processes to be used per energy point."// &
187 " Default is to use all processors (0).", &
188 n_var=1, type_of_var=integer_t, &
189 default_i_val=0)
190 CALL section_add_keyword(section, keyword)
191 CALL keyword_release(keyword)
192
193 CALL keyword_create(keyword, __location__, name="V_SHIFT", &
194 description="Initial value of the Hartree potential shift", &
195 n_var=1, type_of_var=real_t, unit_str="hartree", &
196 default_r_val=0.0_dp)
197 CALL section_add_keyword(section, keyword)
198 CALL keyword_release(keyword)
199
200 CALL keyword_create(keyword, __location__, name="V_SHIFT_OFFSET", &
201 description="Initial offset to determine the optimal shift in Hartree potential.", &
202 n_var=1, type_of_var=real_t, default_r_val=0.10_dp)
203 CALL section_add_keyword(section, keyword)
204 CALL keyword_release(keyword)
205
206 CALL keyword_create(keyword, __location__, name="V_SHIFT_MAX_ITERS", &
207 description="Maximal number of iteration to determine the optimal shift in Hartree potential.", &
208 n_var=1, type_of_var=integer_t, default_i_val=30)
209 CALL section_add_keyword(section, keyword)
210 CALL keyword_release(keyword)
211
212 ! PRINT subsection
213 CALL section_create(subsection, __location__, "PRINT", "Printing of information during the NEGF.", &
214 repeats=.false.)
215
216 CALL create_print_program_run_info_section(print_key)
217 CALL section_add_subsection(subsection, print_key)
218 CALL section_release(print_key)
219
220 CALL create_print_dos_section(print_key, "DOS", "the Density of States (DOS) in the scattering region")
221 CALL section_add_subsection(subsection, print_key)
222 CALL section_release(print_key)
223
224 CALL create_print_dos_section(print_key, "TRANSMISSION", "the transmission coefficient")
225 CALL section_add_subsection(subsection, print_key)
226 CALL section_release(print_key)
227
228 CALL section_add_subsection(section, subsection)
229 CALL section_release(subsection)
230
231 END SUBROUTINE create_negf_section
232
233! **************************************************************************************************
234!> \brief Create NEGF%CONTACT input section.
235!> \param section input section
236!> \par History
237!> * 09.2017 split from create_negf_section() [Sergey Chulkov]
238! **************************************************************************************************
239 SUBROUTINE create_contact_section(section)
240 TYPE(section_type), POINTER :: section
241
242 TYPE(keyword_type), POINTER :: keyword
243 TYPE(section_type), POINTER :: print_key, subsection, subsection2
244
245 cpassert(.NOT. ASSOCIATED(section))
246
247 CALL section_create(section, __location__, name="CONTACT", &
248 description="Section defining the contact region of NEGF setup.", &
249 n_keywords=5, n_subsections=3, repeats=.true.)
250
251 NULLIFY (keyword, print_key, subsection, subsection2)
252
253 CALL create_atomlist_section(subsection, "BULK_REGION", &
254 "the bulk contact adjacent to the screening region.", .false.)
255 CALL section_add_subsection(section, subsection)
256 CALL create_atomlist_section(subsection2, "CELL", &
257 "a single bulk contact unit cell. Bulk Hamiltonian will be contstructed "// &
258 "using two such unit cells instead of performing k-point bulk calculation. "// &
259 "FORCE_EVAL_SECTION must be 0.", .true.)
260 CALL section_add_subsection(subsection, subsection2)
261 CALL section_release(subsection2)
262 CALL section_release(subsection)
263
264 CALL create_atomlist_section(subsection, "SCREENING_REGION", &
265 "the given contact adjacent to the scattering region.", .false.)
266 CALL section_add_subsection(section, subsection)
267 CALL section_release(subsection)
268
269 CALL keyword_create(keyword, __location__, name="FORCE_EVAL_SECTION", &
270 description=" Index of the FORCE_EVAL section which will be used for bulk calculation.", &
271 n_var=1, type_of_var=integer_t, default_i_val=0)
272 CALL section_add_keyword(section, keyword)
273 CALL keyword_release(keyword)
274
275 CALL keyword_create(keyword, __location__, name="ELECTRIC_POTENTIAL", &
276 description="External electrostatic potential applied to the given contact.", &
277 n_var=1, type_of_var=real_t, unit_str="hartree", &
278 default_r_val=0.0_dp)
279 CALL section_add_keyword(section, keyword)
280 CALL keyword_release(keyword)
281
282 CALL keyword_create(keyword, __location__, name="FERMI_LEVEL", &
283 description="Contact Fermi level at the given temperature."// &
284 " If this keyword is not given explicitly, the Fermi level"// &
285 " will be automatically computed prior the actual NEGF calculation.", &
286 n_var=1, type_of_var=real_t, unit_str="hartree", &
287 default_r_val=0.0_dp)
288 CALL section_add_keyword(section, keyword)
289 CALL keyword_release(keyword)
290
291 CALL keyword_create(keyword, __location__, name="REFINE_FERMI_LEVEL", &
292 description="Compute the Fermi level using the value from the FERMI_LEVEL keyword"// &
293 " as a starting point. By default the Fermi level is computed only"// &
294 " when the keyword FERMI_LEVEL is not given explicitly.", &
295 default_l_val=.false., lone_keyword_l_val=.true.)
296 CALL section_add_keyword(section, keyword)
297 CALL keyword_release(keyword)
298
299 CALL keyword_create(keyword, __location__, name="TEMPERATURE", &
300 description="Electronic temperature.", &
301 n_var=1, type_of_var=real_t, unit_str="K", &
302 default_r_val=300.0_dp/kelvin)
303 CALL section_add_keyword(section, keyword)
304 CALL keyword_release(keyword)
305
306 ! PRINT subsection
307 CALL section_create(subsection, __location__, "PRINT", "Print properties for the given contact.", &
308 repeats=.false.)
309
310 CALL create_print_dos_section(print_key, "DOS", "the Density of States (DOS)")
311 CALL section_add_subsection(subsection, print_key)
312 CALL section_release(print_key)
313
314 CALL section_add_subsection(section, subsection)
315 CALL section_release(subsection)
316
317 END SUBROUTINE create_contact_section
318
319! **************************************************************************************************
320!> \brief Create an atomic list section.
321!> \param section NEGF section
322!> \param name name of the new section
323!> \param description section description
324!> \param repeats whether the section can be repeated
325!> \par History
326!> * 02.2017 created [Sergey Chulkov]
327! **************************************************************************************************
328 SUBROUTINE create_atomlist_section(section, name, description, repeats)
329 TYPE(section_type), POINTER :: section
330 CHARACTER(len=*), INTENT(in) :: name, description
331 LOGICAL, INTENT(in) :: repeats
332
333 TYPE(keyword_type), POINTER :: keyword
334
335 cpassert(.NOT. ASSOCIATED(section))
336
337 CALL section_create(section, __location__, name=trim(adjustl(name)), &
338 description="Atoms belonging to "//trim(adjustl(description)), &
339 n_keywords=2, n_subsections=0, repeats=repeats)
340
341 NULLIFY (keyword)
342
343 CALL keyword_create(keyword, __location__, name="LIST", &
344 description="Specifies a list of atoms.", &
345 usage="LIST {integer} {integer} .. {integer}", repeats=.true., &
346 n_var=-1, type_of_var=integer_t)
347 CALL section_add_keyword(section, keyword)
348 CALL keyword_release(keyword)
349
350 CALL keyword_create(keyword, __location__, name="MOLNAME", &
351 description="Specifies a list of named molecular fragments.", &
352 usage="MOLNAME WAT MEOH", repeats=.true., &
353 n_var=-1, type_of_var=char_t)
354 CALL section_add_keyword(section, keyword)
355 CALL keyword_release(keyword)
356 END SUBROUTINE create_atomlist_section
357
358! **************************************************************************************************
359!> \brief Create the PROGRAM_RUN_INFO print section.
360!> \param section section to create
361!> \par History
362!> * 11.2020 created [Dmitry Ryndyk]
363! **************************************************************************************************
364 SUBROUTINE create_print_program_run_info_section(section)
365
366 TYPE(section_type), POINTER :: section
367
368 TYPE(keyword_type), POINTER :: keyword
369
370 CALL cp_print_key_section_create(section, __location__, "PROGRAM_RUN_INFO", &
371 description="Controls the printing of basic information during the NEGF.", &
372 print_level=low_print_level, filename="__STD_OUT__")
373 NULLIFY (keyword)
374
375 CALL keyword_create(keyword, __location__, name="_SECTION_PARAMETERS_", &
376 description="Level starting at which this property is printed", &
377 usage="_SECTION_PARAMETERS_", &
378 default_i_val=low_print_level, lone_keyword_i_val=low_print_level, &
379 enum_c_vals=s2a("on", "off", "silent", "low", "medium", "high", "debug"), &
380 enum_i_vals=(/silent_print_level - 1, debug_print_level + 1, &
381 silent_print_level, low_print_level, &
382 medium_print_level, high_print_level, debug_print_level/))
383 CALL section_add_keyword(section, keyword)
384 CALL keyword_release(keyword)
385
386 CALL keyword_create(keyword, __location__, name="PRINT_LEVEL", &
387 variants=(/"IOLEVEL"/), &
388 description="Determines the verbose level for this section "// &
389 "additionally to GLOBAL%PRINT_LEVEL and SECTION_PARAMETERS, "// &
390 "which switch on printing.", &
391 usage="PRINT_LEVEL HIGH", &
392 default_i_val=low_print_level, enum_c_vals= &
393 s2a("SILENT", "LOW", "MEDIUM", "HIGH", "DEBUG"), &
394 enum_desc=s2a("No output", &
395 "Little output", "Quite some output", "Lots of output", &
396 "Everything is written out, useful for debugging purposes only"), &
397 enum_i_vals=(/silent_print_level, low_print_level, medium_print_level, &
398 high_print_level, debug_print_level/))
399 CALL section_add_keyword(section, keyword)
400 CALL keyword_release(keyword)
401
402 END SUBROUTINE create_print_program_run_info_section
403
404! **************************************************************************************************
405!> \brief Create the DOS print section.
406!> \param section section to create
407!> \param name name of the new section
408!> \param description section description
409!> \par History
410!> * 11.2017 created [Sergey Chulkov]
411! **************************************************************************************************
412 SUBROUTINE create_print_dos_section(section, name, description)
413 TYPE(section_type), POINTER :: section
414 CHARACTER(len=*), INTENT(in) :: name, description
415
416 TYPE(keyword_type), POINTER :: keyword
417
418 CALL cp_print_key_section_create(section, __location__, trim(adjustl(name)), &
419 description="Controls the printing of "//trim(adjustl(description))//".", &
420 print_level=high_print_level, filename="__STD_OUT__")
421 NULLIFY (keyword)
422
423 CALL keyword_create(keyword, __location__, name="FROM_ENERGY", &
424 description="Energy point to start with.", &
425 n_var=1, type_of_var=real_t, unit_str="hartree", &
426 default_r_val=-1.0_dp)
427 CALL section_add_keyword(section, keyword)
428 CALL keyword_release(keyword)
429
430 CALL keyword_create(keyword, __location__, name="TILL_ENERGY", &
431 description="Energy point to end with.", &
432 n_var=1, type_of_var=real_t, unit_str="hartree", &
433 default_r_val=1.0_dp)
434 CALL section_add_keyword(section, keyword)
435 CALL keyword_release(keyword)
436
437 CALL keyword_create(keyword, __location__, name="N_GRIDPOINTS", &
438 description="Number of points to compute.", &
439 n_var=1, type_of_var=integer_t, default_i_val=201)
440 CALL section_add_keyword(section, keyword)
441 CALL keyword_release(keyword)
442 END SUBROUTINE create_print_dos_section
443END MODULE input_cp2k_negf
string_utilities::s2a
Definition string_utilities.F:48
bibliography
collects all references to literature in CP2K as new algorithms / method are included from literature...
Definition bibliography.F:28
bibliography::papior2017
integer, save, public papior2017
Definition bibliography.F:43
bibliography::bailey2006
integer, save, public bailey2006
Definition bibliography.F:43
cp_output_handling
routines to handle the output, The idea is to remove the decision of wheter to output and what to out...
Definition cp_output_handling.F:25
cp_output_handling::debug_print_level
integer, parameter, public debug_print_level
Definition cp_output_handling.F:73
cp_output_handling::low_print_level
integer, parameter, public low_print_level
Definition cp_output_handling.F:73
cp_output_handling::medium_print_level
integer, parameter, public medium_print_level
Definition cp_output_handling.F:73
cp_output_handling::high_print_level
integer, parameter, public high_print_level
Definition cp_output_handling.F:73
cp_output_handling::silent_print_level
integer, parameter, public silent_print_level
Definition cp_output_handling.F:73
cp_output_handling::cp_print_key_section_create
subroutine, public cp_print_key_section_create(print_key_section, location, name, description, print_level, each_iter_names, each_iter_values, add_last, filename, common_iter_levels, citations, unit_str)
creates a print_key section
Definition cp_output_handling.F:174
input_constants
collects all constants needed in input so that they can be used without circular dependencies
Definition input_constants.F:17
input_constants::negfint_method_simpson
integer, parameter, public negfint_method_simpson
Definition input_constants.F:1241
input_constants::negfint_method_cc
integer, parameter, public negfint_method_cc
Definition input_constants.F:1241
input_cp2k_negf
Input section for NEGF based quantum transport calculations.
Definition input_cp2k_negf.F:12
input_cp2k_negf::create_negf_section
subroutine, public create_negf_section(section)
Create NEGF input section.
Definition input_cp2k_negf.F:56
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:426
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:155
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)
creates a list of keywords
Definition input_section_types.F:156
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:504
input_section_types::section_add_subsection
subroutine, public section_add_subsection(section, subsection)
adds a subsection to the given section
Definition input_section_types.F:560
input_section_types::section_release
recursive subroutine, public section_release(section)
releases the given keyword list (see doc/ReferenceCounting.html)
Definition input_section_types.F:231
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::integer_t
integer, parameter, public integer_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
physcon
Definition of physical constants:
Definition physcon.F:68
physcon::kelvin
real(kind=dp), parameter, public kelvin
Definition physcon.F:165
qs_density_mixing_types
module that contains the definitions of the scf types
Definition qs_density_mixing_types.F:14
qs_density_mixing_types::create_mixing_section
subroutine, public create_mixing_section(section, ls_scf)
Create CP2K input section for the mixing of the density matrix to be used only with diagonalization m...
Definition qs_density_mixing_types.F:436
string_utilities
Utilities for string manipulations.
Definition string_utilities.F:16
input_keyword_types::keyword_type
represent a keyword in the input
Definition input_keyword_types.F:88
input_section_types::section_type
represent a section of the input file
Definition input_section_types.F:102