title: Coupled cluster Green function: Model involving single and double excitations.
abstract: In this paper, we report on the development of a parallel implementation of the coupled-cluster (CC) Green function formulation (GFCC) employing single and double excitations in the cluster operator (GFCCSD). A key aspect of this work is the determination of the frequency dependent self-energy, Σ(ω). The detailed description of the underlying algorithm is provided, including approximations used that preserve the pole structure of the full GFCCSD method, thereby reducing the computational costs while maintaining an accurate character of methodology. Furthermore, for systems with strong local correlation, our formulation reveals a diagonally dominate block structure where as the non-local correlation increases, the block size increases proportionally. To demonstrate the accuracy of our approach, several examples including calculations of ionization potentials for benchmark systems are presented and compared against experiment.
authors.affiliation: Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
authors.forename: Kiran
authors.initials: K
authors.lastname: Bhaskaran-Nair
authors.affiliation: William R. Wiley Environmental Molecular Sciences Laboratory, Battelle, Pacific Northwest National Laboratory, K8-91, P.O. Box 999, Richland, Washington 99352, USA.
authors.forename: Karol
authors.initials: K
authors.lastname: Kowalski
authors.affiliation: Cain Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA.
authors.forename: William A
authors.initials: WA
authors.lastname: Shelton