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

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

Program: postahc.x / PHonon / Quantum ESPRESSO (version: 7.5)
------------------------------------------------------------------------


Purpose of postahc.x:

- Read the electron-phonon quantities calculated by ph.x with the
electron_phonon='ahc' option.

- Calculate the phonon-induced electron self-energy in the full matrix form
at a given temperature.

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

&INPUT
   ...specs of namelist variables...
/



========================================================================
NAMELIST: &INPUT

   +--------------------------------------------------------------------
   Variable:       prefix
   
   Type:           CHARACTER
   Default:        'pwscf'
   Description:    Prepended to input/output filenames; must be the same
                   used in the calculation of unperturbed system.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       outdir
   
   Type:           CHARACTER
   Default:        value of the ESPRESSO_TMPDIR environment variable if set;
                    current directory ('./') otherwise
   Description:    Directory containing input, output, and scratch files;
                   must be the same as specified in the calculation of
                   the unperturbed system.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ahc_dir
   
   Type:           CHARACTER
   Status:         REQUIRED
   Description:    Directory where the binary files are located.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       use_irr_q
   
   Type:           LOGICAL
   Default:        .false.
   Description:    If .true., assume that the q points are on the irreducible grid. In this case,
                   the data in "ahc_dir" must have been actually generated from a calculation
                   on an irreducible q grid.
                   Off-diagonal self-energies cannot be computed if use_irr_q = .true.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ahc_nbnd
   
   Type:           INTEGER
   Status:         REQUIRED
   Description:    Number of bands for which the electron self-energy is to be computed. Must be
                   identical to ahc_nbnd of the ph.x run with electron_phonon='ahc'.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ahc_nbndskip
   
   Type:           INTEGER
   Default:        0
   Description:    Number of bands to exclude when computing the self-energy. Must be identical to
                   ahc_nbndskip of the ph.x run with electron_phonon='ahc'.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       flvec
   
   Type:           CHARACTER
   Status:         REQUIRED
   Description:    File containing the normalized phonon displacements written by matdyn.x.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       eta_eV
   
   Type:           REAL
   Status:         REQUIRED
   Description:    Magnitude of the small imaginary component included to smooth the energy
                   denominators, in eV.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       temp_kelvin
   
   Type:           REAL
   Status:         REQUIRED
   Description:    Temperature in Kelvins at which the electron self-energy is calculated.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       efermi_eV
   
   Type:           REAL
   Status:         REQUIRED
   Description:    Fermi energy of the electrons in eV.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       amass_amu(i), i=1,ntyp
   
   Type:           REAL
   Status:         REQUIRED
   Description:    Mass for each atom type in atomic mass unit.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ahc_win_min_eV
   
   Type:           REAL
   Default:        -1.d8
   Description:    Lower bound of active AHC window for the lower Fan term in eV.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       ahc_win_max_eV
   
   Type:           REAL
   Default:        1.d8
   Description:    Upper bound of active AHC window for the lower Fan term in eV.
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       skip_upper
   
   Type:           LOGICAL
   Default:        .false.
   Description:    If .true., skip calculation of the upper Fan self-energy. Also, truncate the
                   Debye-Waller self-energy to include only the low-energy band contribution.
                   (Corresponds to the second term (lower Fan + lower DW) of Eq. (G1-revised) of
                   J.-M. Lihm and C.-H. Park, PRX 12, 039901(E) (2022).)
                   If .false., calculate the contribution of both the high-energy and low-energy
                   bands. In this case, ahc_upfan_iq#.bin files must be present in "ahc_dir".
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       skip_dw
   
   Type:           LOGICAL
   Default:        .false.
   Description:    If .true., skip calculation of the Debye-Waller self-energy.
                   If .false., ahc_dw.bin file must be present in "ahc_dir".
   +--------------------------------------------------------------------
   
   +--------------------------------------------------------------------
   Variable:       adiabatic
   
   Type:           LOGICAL
   Default:        .false.
   Description:    If .true., use the adiabatic approximation when computing the Fan self-energy
                   by ignoring the phonon frequency in the denominator. This approximation is known
                   to be inaccurate and even divergent in some materials (S. Poncé et al., J. Chem.
                   Phys. 143, 102813 (2015)). Therefore, this keyword should be used only for
                   experimental or debugging purposes.
   +--------------------------------------------------------------------
   
===END OF NAMELIST======================================================


This file has been created by helpdoc utility on Wed Sep 03 14:23:33 CEST 2025
