# Input File Description

## Program: postahc.x / PHonon / Quantum ESPRESSO (version: 7.2)

> ### TABLE OF CONTENTS

> > INTRODUCTION

> > &INPUT

> > > ahc_dir | nk | nbnd | nat | nq | ahc_nbnd | ahc_nbndskip | flvec | eta | temp_kelvin | efermi | amass_amu | skip_upperfan | skip_dw

> ### INTRODUCTION

> >     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

ahc_dir | CHARACTER
Status: | REQUIRED

>     Directory where the binary files are located.

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nk | INTEGER
Status: | REQUIRED

>     Number of k points. Must be identical to that of the preceding SCF or NSCF run.

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nbnd | INTEGER
Status: | REQUIRED

>     Number of bands. Must be identical to nbnd of the preceding SCF or NSCF run.

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nat | INTEGER
Status: | REQUIRED

>     Number of atoms. Must be identical to nat of the preceding pw.x and ph.x
>     runs.

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nq | INTEGER
Status: | REQUIRED

>     Number of q points. Must be identical to that of the preceding ph.x run
>     with electron_phonon='ahc'.

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ahc_nbnd | INTEGER
Status: | REQUIRED

>     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'.

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ahc_nbndskip | INTEGER
Default: | 0

>     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'.

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flvec | CHARACTER
Status: | REQUIRED

>     File containing the normalized phonon displacements written by matdyn.x.

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eta | REAL
Status: | REQUIRED

>     Magnitude of the small imaginary component included to smooth the energy
>     denominators, in Ry.

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temp_kelvin | REAL
Status: | REQUIRED

>     Temperature in Kelvins at which the electron self-energy is calculated.

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efermi | REAL
Status: | REQUIRED

>     Fermi energy of the electrons in Ry.

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amass_amu(i), i=1,nat | REAL
Status: | REQUIRED

>     Mass for each atom in atomic mass unit. In postahc.x, amass_amu must be
>     set for each atom, not for each atom type as in other programs.

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skip_upperfan | LOGICAL
Default: | .false.

>     If .true., skip calculation of the upper Fan self-energy.
>     If .false., ahc_upfan_iq#.bin files must be present in ahc_dir.

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skip_dw | LOGICAL
Default: | .false.

>     If .true., skip calculation of the Debye-Waller self-energy.
>     If .false., ahc_dw.bin file must be present in ahc_dir.

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This file has been created by helpdoc utility on Sat Mar 18 19:08:12 CET 2023.