In order to install WEST you need to download the QuantumEspresso 6.1.0.

To compute absorption spectra (BSE), you also need to download and install Qbox.

QuantumEspresso (QE) is an integrated suite of Open-Source computer codes for electronic-structure calculations and materials modeling at the nanoscale, based on density-functional theory (DFT), plane waves (PW), and pseudopotentials (PP). Configure QuantumEspresso by running the configure script that comes with the QE distribution. WEST requires MPI support (ScaLAPACK and OpenMP support is also recommended, but optional). If all the environment variables (compilers, libraries etc.) have been set according to the QE configure guide, this would simply be:

$ git clone -b 'qe-6.1.0' --single-branch --depth 1 QEdir
$ cd QEdir
$ git clone -b 'v4.2.1' --single-branch --depth 1 West
$ ./configure


Note that since v4.0.0 WEST requires dynamic linking and Python3.

It’s now time to create the pw.x, wstat.x, wfreq.x, and westpp.x executables by doing:

$ cd QEdir
$ make pw
$ cd QEdir/West
$ make conf PYT=python3 PYT_LDFLAGS="`python3-config --ldflags --embed`"
$ make all

You have succefully installed QuantumEspresso and WEST if you see the executables pw.x, wstat.x, wfreq.x, and westpp.x created in the QEdir/bin directory.

$ ls QEdir/bin/
... (other content) ...

Congratulations, you are all set for running QuantumEspresso and WEST!