Tensor hypercontraction equation-of-motion second-order approximate coupled cluster: electronic excitation energies in O(N4) time

Edward G Hohenstein; Sara I L Kokkila; Robert M Parrish; Todd J Martínez

doi:10.1021/jp4021905

Tensor hypercontraction equation-of-motion second-order approximate coupled cluster: electronic excitation energies in O(N4) time

J Phys Chem B. 2013 Oct 24;117(42):12972-8. doi: 10.1021/jp4021905. Epub 2013 Sep 11.

Authors

Edward G Hohenstein¹, Sara I L Kokkila, Robert M Parrish, Todd J Martínez

Affiliation

¹ Department of Chemistry and the PULSE Institute, Stanford University , Stanford, California 94305, United States.

PMID: 23964979
DOI: 10.1021/jp4021905

Abstract

The tensor hypercontraction (THC) formalism is applied to equation-of-motion second-order approximate coupled cluster singles and doubles (EOM-CC2). The resulting method, THC-EOM-CC2, is shown to scale as O(N4), a reduction of one order from the formal O(N5) scaling of conventional EOM-CC2. Numerical tests for a variety of molecules show that errors of less than 0.02 eV are introduced into the excitation energies.