Boosting the OEP2-sc method with spin-component scaling

Abstract

The semi-canonical second-order optimised effective potential (OEP2-sc) method [R.J. Bartlett, I. Grabowski, S. Hirata and S. Ivanov, J. Chem. Phys. 122, 034104 (2005). doi:10.1063/1.1809605] is one of the most stable and efficient correlated OEP approaches. In this work, we introduce its scaled-opposite-spin (SOS) variant, named OEP2-SOS-sc. This new method further improves over the OEP2-sc for various properties, including correlation potentials, relaxed densities, and energies, fully retaining the good stability of the original approach. Thus, the OEP2-SOS-sc is an efficient and promising tool for high-level density functional theory simulations.

GRAPHICAL ABSTRACT

Keywords:

• Density functional theory
• spin-component scaling
• optimised effective potential method
• OEP2-sc
• correlation functional

Disclosure statement

No potential conflict of interest was reported by the authors.

Note about Prof. Wolniewicz

We dedicate our research to Professor Lutosław Wolniewicz, our friend, colleague, teacher and mentor. But also, and perhaps most of all, a world-class and outstanding scientist who was and will be an authority for many generations of physicists and computational and quantum chemists. Professor Wolniewicz was a theoretician physicist, incredibly talented, with great possibilities and broad knowledge, and most importantly, he was a person who was able to use his talent. His research and discoveries were of fundamental importance for developing quantum physics, chemistry and astrophysics. The super-accurate calculations of the dissociation energy of the H${}_2$ particles carried out by Kołos and Wolniewicz [82,83] showed a contradiction between the theoretical value and the experimental value known at that time and led to the verification of the experiment. Because they were one of the first theoretical calculations carried out based on quantum mechanics that correct the experiment, they bring the collaboration between theoreticians and experimentalists to a new level.

Additional information

Funding

S.Ś. thanks the Polish National Science Center for the partial financial support under Grant No. 2020/37/B/ST4/02713, whereas I.G. and E.F. thanks for financial support the CANALETTO (Narodowa Agencja Wymiany Akademickiej) project (Nos. PPN/BIL/2018/2/00004 and PO19MO06).