Equation-of-Motion Coupled-Cluster Cumulant Green's Function for Excited States and X-Ray Spectra.

ABSTRACT: Green's function methods provide a robust, general framework within many-body theory for treating electron correlation in both excited states and x-ray spectra. Conventional methods using the Dyson equation or the cumulant expansion are typically based on the GW self-energy approximation. In order to extend this approximation in molecular systems, a non-perturbative real-time coupled-cluster cumulant Green's function approach has been introduced, where the cumulant is obtained as the solution to a system of coupled first order, non-linear differential equations. This approach naturally includes non-linear corrections to conventional cumulant Green's function techniques where the cumulant is linear in the GW self-energy. The method yields the spectral function for the core Gre

SUBMITTER: Vila FD 

PROVIDER: S-EPMC8493088 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature