In this paper we discuss a new formalism for producing an analytic coupled-cluster (CC) 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 corresponding 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 properties whose underlying origins come from coupled many-body interactions but 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 CC with singles and doubles representation of the ground-state wave function.
Coupled-cluster representation of Green function employing modified spectral resolutions of similarity transformed Hamiltonians
K. Kowalski, K. Bhaskaran-Nair, W. A. Shelton; Coupled-cluster representation of Green function employing modified spectral resolutions of similarity transformed Hamiltonians. J. Chem. Phys. 7 September 2014; 141 (9): 094102. https://doi.org/10.1063/1.4893527
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