ChemRxiv
These are preliminary reports that have not been peer-reviewed. They should not be regarded as conclusive, guide clinical practice/health-related behavior, or be reported in news media as established information. For more information, please see our FAQs.
1/1
0/0

The Pole Structure of the Dynamical Polarizability Tensor in Equation-of-Motion Coupled-Cluster Theory

preprint
submitted on 26.08.2018 and posted on 27.08.2018 by Kaushik Nanda, Anna Krylov, Jürgen Gauss
In this Letter, we investigate the pole structure of dynamical polarizabilities computed within the equation-of-motion coupled-cluster (EOM-CC) theory. We show, both theoretically and numerically, that approximate EOM-CC schemes such as, for example, the EOM-CC singles and doubles (EOM-CCSD) model exhibit an incorrect pole structure in which the poles that reflect the excitations from the target state (i.e., the EOM-CC state) are supplemented by artificial poles due to excitations from the coupled-cluster (CC) reference state. These artificial poles can be avoided
by skipping the amplitude response and reverting to a sum-over-states formulation. While numerical results are generally in favor of such a solution, its major drawback
is that this scheme violates size extensivity.

History

Email Address of Submitting Author

knanda@usc.edu

Institution

University of Southern California

Country

United States

ORCID For Submitting Author

0000-0002-3447-6678

Declaration of Conflict of Interest

None

Exports