EOMIP-CCSD(2)*: an efficient method for the calculation of ionization potentials

TitleEOMIP-CCSD(2)*: an efficient method for the calculation of ionization potentials
Publication TypeJournal Article
Year of Publication2015
AuthorsDutta, AKumar, Vaval, N, Pal, S
JournalJournal of Chemical Theory and Computation
Volume11
Issue6
Pagination2461-2472
Date PublishedJUN
ISSN1549-9618
Abstract

A new approximation within the domain of EOMIP-CC method is proposed. The proposed scheme is based on the perturbative truncation of the similarity transformed effective Hamiltonian matrix. We call it the EOMIP-CCSD(2)* method, which scales as noniterative N-6 and its storage requirement is very less, compared to the conventional EOMIP-CCSD method. The existing EOMIP-CCSD(2) method has a tendency to overestimate the ionization potential (IP) values. On the other hand, our new strategy corrects for the problem of such an overestimation, which is evident from the excellent agreement achieved with the experimental values. Furthermore, not only the ionization potential but also geometry and IR frequencies of problematic double radicals are estimated correctly, and the results are comparable to the CCSD(T) method, obviously at lesser computational cost. The EOMIP-CCSD(2)* method works even for the core ionization and satellite IP, where the earlier EOMIP-CCSD(2) approximation dramatically fails.

DOI10.1021/ct500927h
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)5.301
Divison category: 
Physical and Materials Chemistry