Single Reference Treatment of Strongly Correlated H4 and H10 Isomers with Richardson-Gaudin States

Paul Andrew Johnson; A Eugene DePrince 3rd

doi:10.1021/acs.jctc.3c00807

Single Reference Treatment of Strongly Correlated H₄ and H₁₀ Isomers with Richardson-Gaudin States

J Chem Theory Comput. 2023 Nov 28;19(22):8129-8146. doi: 10.1021/acs.jctc.3c00807. Epub 2023 Nov 13.

Authors

Paul Andrew Johnson¹, A Eugene DePrince 3rd²

Affiliations

¹ Département de chimie, Université Laval, Québec, Québec G1V 0A6, Canada.
² Department of Chemistry and Biochemistry, Florida State University, Tallahassee, Florida 32306-4390, United States.

PMID: 37955440
DOI: 10.1021/acs.jctc.3c00807

Abstract

Richardson-Gaudin (RG) states are employed as a variational wave function ansatz for strongly correlated isomers of H₄ and H₁₀. In each case, a single RG state describes the seniority-zero sector quite well. Simple natural orbital functionals offer a cheap and reasonable approximation of the outstanding weak correlation in the seniority-zero sector, while systematic improvement is achieved by performing a configuration interaction in terms of RG states.