*** FILE AUTOMATICALLY CREATED: DO NOT EDIT, CHANGES WILL BE LOST ***

------------------------------------------------------------------------
INPUT FILE DESCRIPTION

Program: kcw.x / KCW / Quantum ESPRESSO (version: 7.2)
------------------------------------------------------------------------


Input data format: { } = optional, [ ] = it depends, # = comment

Structure of the input data:
===============================================================================

&CONTROL
   ...
/

&WANNIER
   ...
/

&SCREEN
   ...
/

&HAM
   ...
/

K_POINTS { tpiba | automatic | crystal | gamma | tpiba_b | crystal_b | tpiba_c | crystal_c }
if (gamma)
   nothing to read
if (automatic)
   nk1, nk2, nk3, k1, k2, k3
if (not automatic)
   nks
   xk_x, xk_y, xk_z,  wk
if (tpipa_b or crystal_b in a 'bands' calculation) see Doc/brillouin_zones.pdf



========================================================================
NAMELIST: &CONTROL

   +--------------------------------------------------------------------
   Variable:       prefix
   
   Type:           CHARACTER
   Default:        'pwscf'
   Description:    Prepended to input/output filenames; must be the same
                   used in the previous PW calculations.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       outdir
   
   Type:           CHARACTER
   Default:        current directory ('./')
   Description:    Directory containing input, output, and scratch files;
                   must be the same as specified in the calculation of
                   previous PW calculation.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       calculation
   
   Type:           CHARACTER
   Default:        ' '
   Description:   
                   Specify the KCW calculation to be done
                   Possible choices:
    
                   'wann2kcw' :
                        Pre-processing to prepare KCW calculation.
                        Read previous PWSCF and possibly W90 outputs and prepare the KCW
                        calculation
    
                   'screen' :
                        Perform the calculation of KCW screening coefficient using a
                        LR approach as described here https://doi.org/10.1021/acs.jctc.7b01116
                        and arXiv:2202.08155
    
                   'ham' :
                        Perform the calculation interpolation and diagonalization of the KI hamiltonian
    
                   'cc' :
                        Computes the (estimated) q+G=0 contribution to the bare and screened KC corrections.
                        A report on this quantities is printed on output and can be used to correct a
                        posteriori a "screen" calculation performed without any corrective scheme ("l_vcut"=.false.)
                        avoiding the need of re-doing a "screen" calculation.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       kcw_iverbosity
   
   Type:           INTEGER
   Default:        1
   Description:    = 0 : minimal output
                   = 1 : as above + performs additional checks.
                   > 1 : as above + additional infos on all the steps.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       kcw_at_ks
   
   Type:           LOGICAL
   Default:        .TRUE.
   Description:    If true the KS canonical orbitals are used instead of Wannier
                   functions. It makes sense for isolated system only.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       read_unitary_matrix
   
   Type:           LOGICAL
   Default:        .FALSE.
   Description:    If true read the Unitary matrix written by Wannier90.
                   Implicitely means a previous wannier90 calculation was
                   performed and a KCW calculation will be performed starting
                   from MLWF. Requires 'write_hr = .true.' in wannier90.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       spread_thr
   
   Type:           REAL
   Default:        0.0001 Ry
   Description:    HARD-CODED FOR NOW. Two or more Wannier functions are considered
                   identical if their spread (self-hartree) differ by less than spread_thr.
                   Requires "check_spread" = .true.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       homo_only
   
   Type:           LOGICAL
   Default:        FALSE
   Description:    If "kcw_at_ks" = .TRUE. only the screening paramenter for the HOMO is
                   calculated. Mainly for a perturbative calculation of the first Ionization
                   Potential in isolated systems.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       l_vcut
   
   Type:           LOGICAL
   Default:        FALSE
   Description:    If .TRUE. the Gygi-Baldereschi scheme is used to deal with
                   the q->0 divergence of the Coulomb integral (bare and screened).
                   Improves the convergence wrt k/q-point sampling.
                   Requires to correctly set "eps_inf" for the calculation of
                   the screened interaction.
                   
                   Use it only for periodic system.
                   For isoleted system use "assume_isolated", instead.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       assume_isolated
   
   Type:           CHARACTER
   Default:        'none'
   Description:   
                   Used to perform calculation assuming the system to be
                   isolated (a molecule or a cluster in a 3D supercell).
                   
                   Currently available choices:
    
                   'none' :
                        (default): regular periodic calculation w/o any correction.
    
                   'martyna-tuckerman', 'm-t', 'mt' :
                        Martyna-Tuckerman correction
                        to both total energy and scf potential. Adapted from:
                        G.J. Martyna, and M.E. Tuckerman,
                        "A reciprocal space based method for treating long
                        range interactions in ab-initio and force-field-based
                        calculation in clusters", J. Chem. Phys. 110, 2810 (1999),
                        doi:10.1063/1.477923.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       spin_component
   
   Type:           INTEGER
   Default:        1
   Description:    Which spin channel to calculate (only collinear calculation).
                   1 = spin up channel
                   2 = spin down channel
                   It has to be consistent with the previous Wannier90
                   calculation (see 'spin' keyword in Wannier90 documentation)
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variables:      mp1, mp2, mp3
   
   Type:           INTEGER
   Default:        -1,-1,-1
   Description:    Parameters of the Monkhorst-Pack grid (no offset).
                   Same meaning as for nk1, nk2, nk3 in the input of pw.x.
                   It has to coincide with the regular mesh used for the
                   wannier90 calculation.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       lrpa
   
   Type:           LOGICAL
   Default:        .FALSE.
   Description:    If .true. the response function is computed neglecting xc
                   effects both in the kernel and in the response function (RPA).
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


========================================================================
NAMELIST: &WANNIER

   +--------------------------------------------------------------------
   Variable:       seedname
   
   Type:           CHARACTER
   Default:        wann
   Description:    The seedname of the previous Wannier90 calculation for occupied states.
                   NOTA BENE: the code implicitely assumed that the seedname for empty
                   state is the same as that for occupied state with "_emp" appended.
                   Keep this in mind when set up the wannier90 inputs.
                   
                   For example:
                   wann.win         is the wannier90 input file for the occupied states.
                   wann_emp.win     is the wannier90 input file for the empty states.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       num_wann_occ
   
   Type:           INTEGER
   Default:        0
   Description:    The number of wannier function for the occupied manifold.
                   It has to coincide with the number of occupied KS orbitals.
                   The whole KS manifold has to be wannierised (no 'exclude_band'
                   option for occupied state, at the moment).
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       num_wann_emp
   
   Type:           INTEGER
   Default:        0
   Description:    The number of wannier function for the empty manifold.
                   It has to coincide with the number of empty wannier function
                   from the previous wannier90 calculation
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       have_empty
   
   Type:           LOGICAL
   Default:        FALSE
   Description:    If true empty state are computed. Require a previous wannier90
                   calculation for the empty manifold. The code search for the
                   unitary matrices in the wannier90 file seedname_emp_u.mat
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       has_disentangle
   
   Type:           LOGICAL
   Default:        FALSE
   Description:    Specify if a disentangle unitary matrix needs to be read. Requires
                   a consisten calcuation from the previous wannier90 run.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       check_ks
   
   Type:           LOGICAL
   Default:        FALSE
   Description:    Specify if a diagonalization of the KS matrix build using the wannier
                   function in input has to be performed. This is mainly for debugging purpose.
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


========================================================================
NAMELIST: &SCREEN

   +--------------------------------------------------------------------
   Variable:       niter
   
   Type:           INTEGER
   Default:        maxter=100
   Description:    Maximum number of iterations in a scf step. If you want
                   more than 100, edit variable "maxter" in PH/phcom.f90
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       nmix
   
   Type:           INTEGER
   Default:        4
   Description:    Number of iterations used in potential mixing.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       tr2
   
   Type:           REAL
   Default:        1e-14
   Description:    Threshold for self-consistency.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       i_orb
   
   Type:           INTEGER
   Default:        -1
   Description:    Perform the screening calculation for a particular orbital.
                   If i_orb = -1 (default) all the orbitals are computed.
                   Assumes values between 1 and the total number of wannier
                   functions.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       eps_inf
   
   Type:           REAL
   Default:        1.d0
   Description:    The macroscopic dielectric constant. Needed for the Gygi-Baldereschi
                   scheme if "l_vcut" = .TRUE.
                   Typically from exp or from a ph.x calculation.
                   
                   NOTA BENE: This would be equivalent to a Makov-Payne correction. It works well
                   for cubic systems. Less well for anisotropic systems.
                   
                   ANISOTROPIC SYSTEMS: In this case a generalization of the GB scheme is implemented
                   based on Nano Lett.,9, 975 (2009). It requires the full dielectric tensor to be provided.
                   The code searches (in the working dir) for a file named "eps.dat" containing the macrospocic
                   dielectric tensor. If it does not find it, the value "eps_inf" provided in input will be
                   used (isotropic approximation). If not even "eps_inf" is provided in input no correction
                   is applied to the screened KC correction.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       check_spread
   
   Type:           LOGICAL
   Default:        .FALSE.
   Description:    If .TRUE. the spread (self-hartree) of the Wannier functions is
                   checked and used to decide whether two or more Wannier functions
                   can be considered "identical" or not. Two Wannier functions are
                   considered identical if their spread (self-hartree) differ by less
                   than 1e-4 Ry (Hard coded for now, see "spread_thr").
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


========================================================================
NAMELIST: &HAM

   +--------------------------------------------------------------------
   Variable:       do_bands
   
   Type:           LOGICAL
   Default:        .FALSE.
   Description:    If .true. the interpolated band structure is computed along
                   a path secified with the K_POINTS card ( see PW documentation
                   https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm1487 )
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       use_ws_distance
   
   Type:           LOGICAL
   Default:        .TRUE.
   Description:    If .true. the position of the Wannier function inside the cell is used
                   to set the proper distance and to have a smoother interpolation. Requires
                   seedname_centres.xyz to be printed by the previous Wannier90 run. If the
                   file is not found it is automatically switched to .FALSE. and only the
                   distance between the cells is used (see also Wannier90 documentation)
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       write_hr
   
   Type:           LOGICAL
   Default:        .TRUE.
   Description:    If .true. the KCW hamiltonain in the Wannier basis and in real spase H(R)_m_n
                   is printed to file. Usefull for furhter post-processing.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       on_site_only
   
   Type:           LOGICAL
   Default:        .FALSE.
   Description:    If .true. only the on-site and diagonal elements of the KCW hamiltonain
                   are computed (R=0 and n=m).
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


========================================================================
CARD: K_POINTS 

   see https://www.quantum-espresso.org/Doc/INPUT_PW.html#idm1487
   
===END OF CARD==========================================================


This file has been created by helpdoc utility on Sat Mar 18 13:50:15 CET 2023
