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Capturing Static and Dynamic Correlation with ΔNO-MP2 and ΔNO-CCSD

preprint
submitted on 26.08.2019 and posted on 28.08.2019 by joshua wallace hollett, Pierre-Francois Loos

The NO method for static correlation is combined with second-order Mller-Plesset perturbation theory (MP2) and coupled-cluster singles and doubles (CCSD) to account for dynamic correlation. The MP2 and CCSD expressions are adapted from nite-temperature CCSD, which includes orbital occupancies and vacancies, and expanded orbital summations. Correlation is partitioned with the aid of damping factors incorporated into the MP2 and CCSD residual equations. Potential energy curves for a selection of diatomics are in good agreement with extrapolated full conguration interaction results (exFCI), and on par with conventional multireference approaches.

Funding

Natural Sciences and Engineering Research Council of Canada (NSERC)

Natural Sciences and Engineering Research Council

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History

Email Address of Submitting Author

pierrefrancois.loos@gmail.com

Institution

Universite Paul Sabatier Toulouse

Country

France

ORCID For Submitting Author

0000-0003-0598-7425

Declaration of Conflict of Interest

No conflict of interest

Version Notes

Version 1.0

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