All-Electron BSE@GW Method with Numeric Atom-Centered Orbitals for Extended Periodic Systems.

Green's function theory has emerged as a powerful many-body approach not only in condensed matter physics but also in quantum chemistry in recent years. We have developed a new all-electron implementation of the BSE@GW formalism using numeric atom-centered orbital basis sets (Liu, C. 2020, 152, 044105). We present our recent developments in implementing this formalism for extended periodic systems. We discuss its numerical implementation and various convergence tests pertaining to numerical atom-centered orbitals, auxiliary basis sets for the resolution-of-identity formalism, and Brillouin zone sampling. Several proof-of-principle examples are presented to compare with other formalisms, illustrating the new all-electron BSE@ method for extended periodic systems.