# Input File Description

## Program: pwcond.x / PWscf / Quantum ESPRESSO (version: 7.2)

> ### TABLE OF CONTENTS

> > INTRODUCTION

> > &INPUTCOND

> > > outdir | prefixt | prefixl | prefixs | prefixr | tran_prefix | max_seconds | recover | band_file | tran_file | save_file | fil_loc | lwrite_cond | loop_ek | lread_cond | lwrite_loc | lread_loc | ikind | iofspin | tk_plot | llocal | bdl | bds | bdr | nz1 | energy0 | denergy | nenergy | start_e | last_e | start_k | last_k | ecut2d | ewind | epsproj | orbj_in | orbj_fin

> > K_and_Energy_Points

> > > nkpts | kx | ky | weight | nenergy

> ### INTRODUCTION

> >     This program computes the transmittance of a system and/or its
> >     complex band structure.
> >     It is controlled through the following variables
> >     in the namelist inputcond.

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

> >        &INPUTCOND
> >          ...
> >        /

## Namelist: &INPUTCOND

outdir | CHARACTER

>     temporary directory (as in PWscf)

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prefixt | CHARACTER

>     prefix for the file (as in PWscf) containing all the
>     regions (left lead + scatt. reg. + right lead)

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prefixl | CHARACTER

>     prefix for the file containing only the        left lead

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prefixs | CHARACTER

>     prefix for the file containing the scattering region

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prefixr | CHARACTER

>     prefix for the file containing only the right lead

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tran_prefix | CHARACTER
Default: | none
See: | recover

>     if tran_prefix is specified the program will save partial results
>     of a transmission calculation (ikind .GE. 1) in a specific
>     directory (outdir/tran_prefix.cond_save)

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max_seconds | REAL
Default: | 1.D+7, or 150 days, i.e. no time limit
See: | tran_prefix

>     jobs stops after max_seconds elapsed time (wallclock time).
>     It can be enabled only if tran_prefix is specified.

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recover | LOGICAL
Default: | .FALSE.
See: | tran_prefix

>     restarts a previously interrupted transmission calculation (only if
>     tran_prefix was specified). It can also be used to gather partial
>     results from a calculation that was split by using start_e,last_e
>     and/or start_k,last_k (see corresponding keywords).

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band_file | CHARACTER

>     file on which the complex bands are saved

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tran_file | CHARACTER

>     file where the transmission is written

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save_file | CHARACTER

>     file where the data necessary for PWCOND are written
>     so that no prefix files of PW are longer needed

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fil_loc | CHARACTER

>     file on/from which the 2D eigenvalue problem data are
>     saved/read

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lwrite_cond | LOGICAL

>     if .t. save the data necessary for PWCOND in save_file

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loop_ek | LOGICAL

>     if .t. the energy loop is outside the k-point loop

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lread_cond | LOGICAL

>     if .t. read the data necessary for PWCOND from save_file

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lwrite_loc | LOGICAL

>     if .t. save 2D eigenvalue problem result in fil_loc

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lread_loc | LOGICAL

>     if .t. read 2D eigenvalue problem result from fil_loc

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ikind | INTEGER

>     The kind of conductance calculation:

>     ikind=0  - just complex band structure (CBS) calculation

>     ikind=1  - conductance calculation with identical
>                left and right leads

>     ikind=2  - conductance calculation with different
>                left and right leads

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iofspin | INTEGER

>     spin index for which the calculations are performed

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tk_plot | INTEGER

>     if > 0, plot T(kx,ky) at each energy in the region [tk_plot x full BZ]

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llocal | LOGICAL

>     if .t. calculations are done with only local part of PP

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bdl | REAL

>     right boundary of the left lead (left one is supposed to be at 0)
>     (in units of lattice parameter "alat" defined in the scf run)

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bds | REAL

>     right boundary of the scatt. reg. (left one is at 0 if prefixs
>     is used and = bdl if prefixt is used)
>     (in units of lattice parameter "alat" defined in the scf run)

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bdr | REAL

>     right boundary of the right lead (left one is at 0 if prefixr
>     is used and = bds if prefixt is used)
>     (in units of lattice parameter "alat" defined in the scf run)

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nz1 | INTEGER

>     the number of subslabs in the slab (to calculate integrals)

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energy0 | REAL

>     initial energy

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denergy | REAL

>     energy step (if denergy=0.0 the energy is read from the list)

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nenergy | INTEGER

>     number of energies

>     WARNING: the energy in input file is given in eV taken from Ef,
>              and denergy should be negative

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start_e | INTEGER
Default: | 1
See: | last_e

>     if start_e > 1, the scattering problem is solved only for those
>     energies with index between start_e and last_e in the energy list.

>     NOTE: start_e <= last_e and start_e <= nenergy must be satisfied

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last_e | INTEGER
Default: | nenergy
See: | start_e

>     index of the last energy to be computed. If last_e > nenergy,
>     then last_e will be automatically set to nenergy.

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start_k | INTEGER
Default: | 1
See: | last_k

>     if start_k > 1, the scattering problem is solved only for those
>     k-points with index between start_k and last_k in the k-point list.
>     In order to recover the full transmission (i.e. integrated over the
>     full Brillouin Zone) at the end, perform the partial runs specifying
>     a value for tran_prefix (the restart directory), then put all the
>     partial transmission files 'transmission_k#_e#' inside a unique
>     restart directory and run pwcond.x with recover=.TRUE. (without
>     specifying any value for start_k and last_k).

>     NOTE: start_k <= last_k must be satisfied and start_k must also
>        not be greater than the actual number of k-point in the list
>        (if you compute the grid automatically by specifying the grid
>        size and shifts, you can use kpoints.x to check that number).

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last_k | INTEGER
Default: | nenergy
See: | start_k

>     index of the last k-point to be computed. If last_k is bigger than the
>     actual number of points in the list, then it will be set to that number.

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ecut2d | REAL

>     2-D cutoff

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ewind | REAL

>     the energy window for reduction of 2D plane wave basis set (in XY)

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epsproj | REAL

>     accuracy of 2D basis set reduction

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orbj_in | REAL

>     the initial orbital for projecting the transmission

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orbj_fin | REAL

>     the final orbital for projecting the transmission

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## Card: K_and_Energy_Points

### Syntax:

> nkpts

> kx(1) | ky(1) | weight(1)
> kx(2) | ky(2) | weight(2)
> . . .
> kx(nkpts) | ky(nkpts) | weight(nkpts)

> nenergy

### Description of items:

> nkpts | INTEGER

> >     Number of k_\perp points

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> kx, ky, weight | REAL

> >     k-point coordinates and weights

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> nenergy | INTEGER

> >     number of energy points

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This file has been created by helpdoc utility on Sat Mar 18 13:46:52 CET 2023.