All-electron BSE@GW method for Extended Systems with Numeric Atom-Centered Orbitals

BSE@GW method has emerged as a powerful many-body perturbation theory approach not only in condensed matter physics but also in quantum chemistry in recent years. Over the last several years, we have been developing a new all-electron implementation of the BSE@GW formalism using numeric atom-centered orbital basis sets in FHI-aims code. In this talk, we will discuss our recent developments in implementing this formalism for extended systems with the periodic boundary conditions. We will discuss its implementation and numerical challenges. We will present various convergence tests pertaining to numerical atomic orbitals, auxiliary basis set for the resolution-of-identity formalism, and Brillion zone sampling, etc. Several proof-of-principle examples will be presented to compare with other formalisms, illustrating the new all-electron BSE@GW method for extended systems.