Study of cumulant approximations to n-electron valence multireference perturbation theory

TitleStudy of cumulant approximations to n-electron valence multireference perturbation theory
Publication TypeJournal Article
Year of Publication2009
AuthorsZgid, D, Ghosh, D, Neuscamman, E, Chan, GKin-Lic
JournalJournal of Chemical Physics
Volume130
Issue19
PaginationArticle Number: 194107
Date PublishedMAY
Abstract

We investigate the possibility of reducing the complexity of multireference perturbation theory through cumulant based approximations to the high-order density matrices that appear in such theories. Our test cases show that while the cumulant approximated forms are degraded in accuracy relative to the parent theory and exhibit intruder state problems that must be carefully handled, they may provide a route to a simple estimation of dynamic correlation when the parent perturbation theory is infeasible. Nonetheless, further work is clearly needed on better approximations to the denominators in the perturbation theory.

DOI10.1063/1.3132922
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

2.894

Divison category: 
Physical and Materials Chemistry