  The SternheimerGW software uses time-dependent density-functional
perturbation theory to evaluate GW quasiparticle band structures and spectral
functions for solids. Both the Green's function G and the screened Coulomb
interaction W are obtained by solving linear Sternheimer equations, thus
overcoming the need for a summation over unoccupied states. The code targets
the calculation of accurate spectral properties by convoluting G and W using a
full frequency integration. The linear response approach allows users to
evaluate the spectral function at arbitrary electron wavevectors, which is
particularly useful for indirect band gap semiconductors and for simulations of
angle-resolved photoelectron spectra. The software is parallelized efficiently,
integrates with version 6.3 of Quantum Espresso, and is continuously monitored
for stability using a test farm.
