PNNL

Abstract

In this paper we discuss a new formalism for producing an analytic coupled-cluster (CC) Green’s function that renders a highly scalable computational accurate method for producing an analytic coupled-cluster Green’s function for an N-electron system by shifting the poles of similarity transformed Hamiltonians represented in N-1 and N +1 electron Hilbert spaces. Simple criteria are derived for the states in N -1 and N + 1 electron spaces that are then corrected in the spectral resolution of the cor- responding matrix representations of the similarity transformed Hamiltonian. The accurate description of excited state processes within a Green’s function formalism would be of significant importance to a number of scientific communities ranging from physics and chemistry to engineering and the biological sciences. This is because the Green’s function methodology provides a direct path for not only calculating prop- erties whose underlying origins come from coupled many-body interactions but it also provides a straightforward path for calculating electron transport, response and correlation functions that allows for a direct link with experiment. As a special case of this general formulation, we discuss the application of this technique for Green’s function defined by the CCSD (CC with singles and doubles) representation of the ground-state wave function.