EPW (Electron-Phonon coupling using Wannier functions) is a program written in FORTRAN90 for calculating the electron-phonon coupling in periodic systems using density-functional perturbation theory and maximally-localized Wannier functions. EPW can calculate electron-phonon interaction self-energies, electron-phonon spectral functions, and total as well as mode-resolved electron-phonon coupling strengths. The calculation of the electron-phonon coupling requires a very accurate sampling of electron-phonon scattering processes throughout the Brillouin zone, hence reliable calculations can be prohibitively time-consuming. EPW combines the Kohn-Sham electronic eigenstates and the vibrational eigenmodes provided by the Quantum-ESPRESSO package [1] with the maximally localized Wannier functions provided by the wannier90 package [2] in order to generate electron-phonon matrix elements on arbitrarily dense Brillouin zone grids using a generalized Fourier interpolation. This feature of EPW leads to fast and accurate calculations of the electron-phonon coupling, and enables the study of the electron-phonon coupling in large and complex systems.
@article{arxiv.1005.4418,
title = {EPW: A program for calculating the electron-phonon coupling using maximally localized Wannier functions},
author = {Jesse Noffsinger and Feliciano Giustino and Brad D. Malone and Cheol-Hwan Park and Steven G. Louie and Marvin L. Cohen},
journal= {arXiv preprint arXiv:1005.4418},
year = {2015}
}