Input File Description

Program: pwcond.x / PWscf / Quantum Espresso (version: 6.2)

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)
         
prefixt CHARACTER
prefix for the file (as in PWscf) containing all the
regions (left lead + scatt. reg. + right lead)
         
prefixl CHARACTER
prefix for the file containing only the        left lead
         
prefixs CHARACTER
prefix for the file containing the scattering region
         
prefixr CHARACTER
prefix for the file containing only the right lead
         
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)
         
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.
         
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).
         
band_file CHARACTER
file on which the complex bands are saved
         
tran_file CHARACTER
file where the transmission is written
         
save_file CHARACTER
file where the data necessary for PWCOND are written
so that no prefix files of PW are longer needed
         
fil_loc CHARACTER
file on/from which the 2D eigenvalue problem data are
saved/read
         
lwrite_cond LOGICAL
if .t. save the data necessary for PWCOND in save_file
         
loop_ek LOGICAL
if .t. the energy loop is outside the k-point loop
         
lread_cond LOGICAL
if .t. read the data necessary for PWCOND from save_file
         
lwrite_loc LOGICAL
if .t. save 2D eigenvalue problem result in fil_loc
         
lread_loc LOGICAL
if .t. read 2D eigenvalue problem result from fil_loc
         
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
         
iofspin INTEGER
spin index for which the calculations are performed
         
tk_plot INTEGER
if > 0, plot T(kx,ky) at each energy in the region [tk_plot x full BZ]
         
llocal LOGICAL
if .t. calculations are done with only local part of PP
         
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)
         
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)
         
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)
         
nz1 INTEGER
the number of subslabs in the slab (to calculate integrals)
         
energy0 REAL
initial energy
         
denergy REAL
energy step (if denergy=0.0 the energy is read from the list)
         
nenergy INTEGER
number of energies

WARNING: the energy in input file is given in eV taken from Ef,
         and denergy should be negative
         
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
         
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.
         
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).
         
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.
         
ecut2d REAL
2-D cutoff
         
ewind REAL
the energy window for reduction of 2D plane wave basis set (in XY)
         
epsproj REAL
accuracy of 2D basis set reduction
         
orbj_in REAL
the initial orbital for projecting the transmission
         
orbj_fin REAL
the final orbital for projecting the transmission
         

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
               
kx, ky, weight REAL
k-point coordinates and weights
                  
nenergy INTEGER
number of energy points
               
This file has been created by helpdoc utility on Mon Oct 23 19:37:27 CEST 2017.