QE-bands

A visualisation tool for Quantum ESPRESSO band structures in Python.

This package is inspired heavily by the CASTEP-bands package for the CASTEP plane-wave pseudopotential electronic structure code.

Installation

Installation is done via pip using the following command

pip install https://github.com/Inker2401/QEbands.git

In addition to the usual scientific Python dependencies (NumPy and Matplotlib), this package also requires the following:

• Atomic Simulation Environment (ASE)
• Spglib

Usage

You are encouraged to consult the examples folder to see some example plots in some systems. In addition, bear in mind the following:

• All the data is stored in the BandData class. This class may be initialised in the following way (see test folder for each possible initialisation)

  1. the Quantum ESPRESSO XML file for a bands run (recommended)
  2. the standard output of a PWSCF run
  3. the standard output of a PWSCF run with the post-processed output of the bands.x utility.

• Note some class attributes are not initialised without an XML file, notably the nelec_spin which contains the number of electrons for each spin channel.

• The definitions of high-symmetry points are those of W. Setyawan and S. Curtarolo, Comp. Mat. Sci. 49 (2010).

• *Very important! QEbands assumes that the k-points used in a bandstructure are equally spaced apart. This may not be the case if you use the default path generation capabilties of Quantum ESPRESSO. Instead it is recommended that you use a tool like the

  The ASE package can generate band structure paths paths using the aforementioned definitions of high-symmetry points that have equally spaced k-points.

• Unless otherwise stated (for instance through parameters for functions), the appearance of the plot is dictated by the current matplotlib rcParams.

• A notable exception to the previous point BandsData.setup_axes for setting up the actual band structure axes. In general, you should call this function after initialising any matplotlib Axes object prior to any actual plotting tasks.

This package has been tested on Quantum ESPRESSO version >= 7.0. While it may work on older versions, there are no guarantees...

License

Copyright (C) 2025 V. Ravindran This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.