Lower scaling approximation to EOM-CCSD: a critical assessment of the ionization problem

TitleLower scaling approximation to EOM-CCSD: a critical assessment of the ionization problem
Publication TypeJournal Article
Year of Publication2018
AuthorsDutta, AKumar, Vaval, N, Pal, S
JournalInternational Journal of Quantum Chemistry
Volume118
Issue14
Paginatione25594
Date PublishedJUL
ISSN0020-7608
KeywordsEOM-CCSD, Ionization potential, lower scaling
Abstract

In this article, we investigate the performance of different approximate variants of the EOM-CCSD method for calculation of ionization potential (IP), as compared to EOM-CCSDT reference values. None of the lower scaling approximations to the EOM-CCSD method give a consistent performance for valence, inner valence, and core ionization, favoring one, or the other depending on the nature of the approximation used. The parent EOMIP-CCSD method gives superior performance for valence IP but can show large errors for inner valence and core ionization. The problem is particularly severe for core-ionization, where even the EOMIP-CCSDT method cannot provide quantitative accuracy.

DOI10.1002/qua.25594
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

2.920

Divison category: 
Physical and Materials Chemistry