EPW: Electron-phonon Coupling, Transport and Superconducting Properties Using Maximally Localized Wannier Functions

The EPW (Electron-Phonon coupling using Wannier functions) software is a Fortran90 code that uses density-functional perturbation theory and maximally localized Wannier functions for computing electron-phonon couplings and related properties in solids accurately and efficiently. The EPW v4 program can be used to compute electron and phonon self-energies, linewidths, electron-phonon scattering rates, electron-phonon coupling strengths, transport spectral functions, electronic velocities, resistivity, anisotropic superconducting gaps and spectral functions within the Migdal-Eliashberg theory. The code now supports spin-orbit coupling, time-reversal symmetry in non-centrosymmetric crystals, polar materials, and k and q-point parallelization. Considerable effort was dedicated to optimization and parallelization, achieving almost a ten times speedup with respect to previous releases. A computer test farm was implemented to ensure stability and portability of the code on the most popular compilers. and architectures. Since April 2016, version 4 of the EPW code is fully integrated in and distributed with the Quantum ESPRESSO package, and can be downloaded through QE-forge at http://qe-forge.org/gf/project/q-e.Program summaryProgram title: EPWCatalogue identifier: AEHA_v2_0Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEHA_v2_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GNU General Public Licence 3No. of lines in distributed program, including test data, etc.: 1635099No. of bytes in distributed program, including test data, etc.: 22533187Distribution format: tar.gzProgramming language: Fortran 90, MPI.Computer: Non-specific.Operating system: Unix/Linux.RAM: Typically 2GB/coreClassification: 7.3, 7.8, 7.9.External routines: LAPACK, BLAS, MPI, FFIW, Quantum-ESPRESSO package [1]Does the new version supersede the previous version?: YesNature of problem:Calculation of electron and phonon self-energies, linewidths, electron-phonon scattering rates, electron-phonon coupling strengths, transport spectral functions, electronic velocities, resistivity, anisotropic superconducting gaps and spectral functions within the Migdal-Eliashberg theory.Solution method:The code relies on density-functional perturbation theory and maximally localized Wannier functions.Reasons for new version:New features (listed in the paper) and optimization of the code.Summary of revisions:Recent developments and new functionalities are described in Section 2 of the paper.Running time:Up to several hours on several tens of processors. (C) 2016 Elsevier B.V. All rights reserved.