A minimalistic approach to static and dynamic electron correlations: Amending generalized valence bond method with extended random phase approximation correlation correction

Journal Article · Tue Jun 28 04:00:00 EDT 2016 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4954694· OSTI ID:22676005

Chatterjee, Koushik; Jawulski, Konrad ^[1]; Pastorczak, Ewa; Pernal, Katarzyna ^[2]

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1. Institute of Applied Radiation Chemistry, Lodz University of Technology, ul. Wroblewskiego 15, 93-590 Lodz (Poland)
2. Institute of Physics, Lodz University of Technology, ul. Wolczanska 219, 90-924 Lodz (Poland)

A perfect-pairing generalized valence bond (GVB) approximation is known to be one of the simplest approximations, which allows one to capture the essence of static correlation in molecular systems. In spite of its attractive feature of being relatively computationally efficient, this approximation misses a large portion of dynamic correlation and does not offer sufficient accuracy to be generally useful for studying electronic structure of molecules. We propose to correct the GVB model and alleviate some of its deficiencies by amending it with the correlation energy correction derived from the recently formulated extended random phase approximation (ERPA). On the examples of systems of diverse electronic structures, we show that the resulting ERPA-GVB method greatly improves upon the GVB model. ERPA-GVB recovers most of the electron correlation and it yields energy barrier heights of excellent accuracy. Thanks to a balanced treatment of static and dynamic correlation, ERPA-GVB stays reliable when one moves from systems dominated by dynamic electron correlation to those for which the static correlation comes into play.

• OSTI ID: 22676005
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 24 Vol. 144; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
COMPUTERIZED SIMULATION
CORRECTIONS
ELECTRON CORRELATION
ELECTRONIC STRUCTURE
RANDOM PHASE APPROXIMATION