Abstract

Accurate ab-initio calculations of electron-phonon properties in crystalline solids are still a challenging topic due to the considerable computational effort of such calculations. Additional difficulties arise in the case of polar materials, where the electrons can be strongly coupled to the macroscopic electric field induced by optical phonons at long wavelength (Fröhlich coupling). In this talk I will present a method for calculating the electron-phonon vertex in polar semiconductors and insulators from first principles. The formalism is a generalization of the Fröhlich vertex to the case of anisotropic materials and multiple phonon branches, and can be used either as a postprocessing correction to standard electron-phonon calculations, or in conjunction with ab initio interpolation based on maximally localized Wannier functions as implemented in the EPW code. I will demonstrate this formalism by investigating the electron-phonon interactions in two technologically relevant materials, anatase TiO2 and the methylammonium lead halide perovskite MAPbI3.