Perturbative approximation to hybrid equation of motion coupled cluster/effective fragment potential method

TitlePerturbative approximation to hybrid equation of motion coupled cluster/effective fragment potential method
Publication TypeJournal Article
Year of Publication2014
AuthorsGhosh, D
JournalJournal of Chemical Physics
Volume140
Issue9
Pagination094101
Date PublishedMAR
ISSN0021-9606
Abstract

Hybrid quantum mechanics/molecular mechanics (QM/MM) methods provide an attractive way to closely retain the accuracy of the QM method with the favorable computational scaling of the MM method. Therefore, it is not surprising that QM/MM methods are being increasingly used for large chemical/biological systems. Hybrid equation of motion coupled cluster singles doubles/effective fragment potential (EOM-CCSD/EFP) methods have been developed over the last few years to understand the effect of solvents and other condensed phases on the electronic spectra of chromophores. However, the computational cost of this approach is still dominated by the steep scaling of the EOM-CCSD method. In this work, we propose and implement perturbative approximations to the EOM-CCSD method in this hybrid scheme to reduce the cost of EOM-CCSD/EFP. The timings and accuracy of this hybrid approach is tested for calculation of ionization energies, excitation energies, and electron affinities of microsolvated nucleic acid bases (thymine and cytosine), phenol, and phenolate. (C) 2014 AIP Publishing LLC.

DOI10.1063/1.4866838
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)3.02
Divison category: 
Physical and Materials Chemistry