Input File Description

Program: bands.x / PWscf / Quantum Espresso

TABLE OF CONTENTS

INTRODUCTION

&BANDS

prefix | outdir | filband | spin_component | lsigma | lsym | no_overlap | plot_2d | firstk | lastk

INTRODUCTION

Purpose of bands.x:
    Rewrite the bands ordering them using the overlap
    of the wave-functions on neighbor k points
    and calculate properties of each eigen-function.

Presently it can calculate:

   (a) The expectation value of the spin operator on each spinor
       wave-function.
   (b) The symmetry properties of each wavefunction. With this option
       the bands are not ordered according to the overlap.

The input data of this program are read from standard input
or from a file and have the following format:


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

   &BANDS
     ...
   /

Namelist: BANDS

prefix CHARACTER 
prefix of files saved by program pw.x
outdir CHARACTER
Default: value of the ESPRESSO_TMPDIR environment variable if set; current directory ('./') otherwise 
directory containing the input data,
i.e. the same as in pw.x
filband CHARACTER 
file "filband" contains the bands
spin_component INTEGER 
In the lsda case select:

   1 = spin-up
   2 = spin-down
lsigma(i), i=1,3 LOGICAL 
If true writes a file filband.i with the expectation
values of the spin operator on the spinor wave-functions.
(only in the noncollinear case).
lsym LOGICAL 
If .true. the bands are classified according to the
irreducible representations of the small group of k. A
file "filband".rap with the same format of "filband"
is written.
no_overlap LOGICAL
Default: .false. 
If .true. writes the eigenvalues in the output file
without changing their order.
plot_2d LOGICAL
Default: .false. 
If .true. writes the eigenvalues in the output file
in a 2D format readable by gnuplot. Band ordering is not
changed. Each band is written in a different file called
filband.# with the format:
xk, yk, energy
xk, yk, energy
..  ..  ..
energies are written in eV and xk in units 2\pi/a.
firstk, lastk INTEGER 
if lsym=.true. makes the symmetry analysis only for k
points between firstk to lastk
This file has been created by helpdoc utility.