About ##### EPWpy is an open-source python code which wraps EPW code for automated calculations. EPWpy provides python objects with methods that can be used to automate DFT+EPW calculations using Quantum Espresso and EPW.EPWpy also provides a series of visualization utilities for plotting various quantities. EPW is a F90/MPI code which calculates properties related to the electron-phonon interaction using `Density-Functional Perturbation Theory `_ and `Maximally Localized Wannier Functions `_. The name is derived from the words "Electron-phonon Wannier" which refer to the Wannier-Fourier interpolation method employed by the code. The development of EPWpy is led by `Sabyasachi Tiwari `_, `Bruno Cucco `_, and `Feliciano Giustino `_. The most recent reference technical manuscript is: `S. Tiwari, B. Cucco, M. Zacharias, J-L. Bartolome, S. Mishra, W. Yang, V-A. Ha, S. Ponce, E. Kioupakis, R. Margine, and F. Giustino, “EPWpy: A python program for ab-initio many-body calculations”, Unpublished (2024) `_. The EPWpy code is written by Sabyasachi Tiwari (EPWpy v1.0) while in the Giustino group at the University of Texas at Austin. As of Nov 2024, the EPWpy Collaboration includes: Sabyasachi Tiwari, Bruno Cucco, Viet-Anh Ha, Jon Lafuente-Bartolomé, Shashi Mishra, Marios Zacharias, Wooil Yang, Samuel Poncé, Emmanouil Kioupakis, Roxana Margine, and Feliciano Giustino. EPWpy is developed under git within the `EPW GitLab `_ portal. As of Nov 2024, EPWpy consists of 8,464 lines of code (including comments). Computing electron-phonon properties with EPWpy --------------------------------------------- Currently EPWpy supports all functionalities which EPW can compute. EPW can be used to compute: * The total electron-phonon coupling strenght * The anisotropic Eliashberg spectral function * The transport spectral function * The anisotropic superconducting gap within the Eliashberg theory * The electron and phonon self-energies arising from the electron-phonon interaction * The phonon linewidths and lifetimes arising from the electron-phonon interaction * The electron linewidths and lifetimes arising from the electron-phonon interaction * The temperature-dependence of the carrier lifetimes * The spectral functions needed for the calculation of ARPES spectra * The temperature-dependent electron and hole mobility within the Boltzmann transport formalism * Magnetortransport coefficients such as the Hall mobility * Small and large polarons * Indirect phonon-assisted optical absorption * Temperature-dependent properties using the special displacement method * Direct plus indirect phonon-assisted absorption within quasidegenerate perturbation theory Current interfaces in EPWpy --------------------------------------------- Currently, EPWpy interfaces EPW with Quantum Espresso and BerkeleyGW. EPWpy also interfaces with Wannier90. The methods for BerkeleyGW implemented in EPWpy are the following: * epsilon * sigma * sigma2wan * kernel * absorption