mirror of https://gitlab.com/QEF/q-e.git
114 lines
3.9 KiB
Fortran
114 lines
3.9 KiB
Fortran
!
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! Copyright (C) 2020 Quantum ESPRESSO group
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! This file is distributed under the terms of the
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! GNU General Public License. See the file `License'
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! in the root directory of the present distribution,
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! or http://www.gnu.org/copyleft/gpl.txt .
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!
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!--------------------------------------------------------------------
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MODULE dft_setting_params
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!----------------------------------------------------------------
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!! Parameters that define the XC functionals.
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!
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USE kind_l, ONLY: DP
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#if defined(__LIBXC)
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USE xc_f03_lib_m
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#endif
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!
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IMPLICIT NONE
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!
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SAVE
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!
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CHARACTER(LEN=32) :: dft = 'not set'
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!! Full name of the XC functional
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INTEGER, PARAMETER :: notset = -1
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!! Value of indexes that have not been set yet
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!
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LOGICAL :: is_libxc(6) = .FALSE.
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!! \(\text{is_libxc(i)}=TRUE\) if the i-th term of the input
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!! functional is from Libxc
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!
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LOGICAL :: libxc_initialized(6) = .FALSE.
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!! TRUE if libxc functionals have been initialized
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!
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#if defined(__LIBXC)
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TYPE(xc_f03_func_t) :: xc_func(6)
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!! pointers to libxc functional structs
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TYPE(xc_f03_func_info_t) :: xc_info(6)
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!! pointers to libxc info structs
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INTEGER :: libxc_flags(6,0:15) = notset
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!! flags related to specific features of libxc functionals
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!! (see Libxc doc)
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INTEGER :: n_ext_params(6) = 0
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!! number of external parameters for each functional
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REAL(DP) :: par_list(6,50)
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!! list of external parameters
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LOGICAL :: xc_kind_error = .FALSE.
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!! some Libxc dfts are currently not usable in QE (for example
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!! kinetic dfts). If one of them is detected this variable is
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!! set to TRUE.
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#endif
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!
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LOGICAL :: exx_started = .FALSE.
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!! TRUE if Exact Exchange is active
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REAL(DP) :: exx_fraction = 0.0_DP
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!! Exact Exchange fraction parameter
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!
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INTEGER :: iexch = notset
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!! LDA exchange index
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INTEGER :: icorr = notset
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!! LDA correlation index
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REAL(DP) :: finite_size_cell_volume = -1._DP
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!! Cell volume parameter for finite size correction
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REAL(DP) :: rho_threshold_lda = 1.E-10_DP
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!! Threshold value for the density in LDA
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!
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INTEGER :: igcx = notset
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!! GGA exchange index
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INTEGER :: igcc = notset
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!! GGA correlation index
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REAL(DP) :: rho_threshold_gga = 1.E-6_DP
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!! Threshold value for the density in GGA
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REAL(DP) :: grho_threshold_gga = 1.E-10_DP
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!! Threshold value for the density gradient in GGA
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REAL(DP) :: screening_parameter
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!! Screening parameter for PBE exchange
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REAL(DP) :: gau_parameter
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!! Gaussian parameter for PBE exchange
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!
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INTEGER :: imeta = notset
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!! MGGA exchange index
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INTEGER :: imetac = notset
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!! MGGA correlation index
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REAL(DP) :: rho_threshold_mgga = 1.E-12_DP
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!! Threshold value for the density in MGGA
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REAL(DP) :: grho2_threshold_mgga = 1.E-24_DP
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!! Threshold value for the density gradient (square modulus) in MGGA
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REAL(DP) :: tau_threshold_mgga = 1.0E-12_DP
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!! Threshold value for the density laplacian in MGGA
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!
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!
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LOGICAL :: islda = .FALSE.
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!! TRUE if the functional is LDA only
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LOGICAL :: isgradient = .FALSE.
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!! TRUE if the functional is GGA
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LOGICAL :: has_finite_size_correction = .FALSE.
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!! TRUE if finite size correction is present
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LOGICAL :: finite_size_cell_volume_set = .FALSE.
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!! TRUE if the cell volume has been set for finite size correction.
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LOGICAL :: ismeta = .FALSE.
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!! TRUE if the functional is MGGA
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LOGICAL :: ishybrid = .FALSE.
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!! TRUE if the functional is hybrid
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LOGICAL :: scan_exx = .FALSE.
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!! TRUE if SCAN0 functional is active
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!
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LOGICAL :: discard_input_dft = .FALSE.
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!! TRUE if input DFT can be overwritten
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INTEGER :: beeftype = -1
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!! Index for BEEF functional
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INTEGER :: beefvdw = 0
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!! Index for vdw term of BEEF
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!
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END MODULE dft_setting_params
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