Kohn–Sham energy decomposition for molecules in a magnetic field

Reimann, Sarah; Borgoo, Alex; Austad, Jon; Tellgren, Erik I.; Teale, Andrew M.; Helgaker, Trygve; Stopkowicz, Stella

Abstract

We study the total molecular electronic energy and its Kohn–Sham components within the framework of magnetic-field density-functional theory (BDFT), an alternative to current-dependent density-functional theory (CDFT) for molecules in the presence of magnetic fields. For a selection of closed-shell dia- and paramagnetic molecules, we investigate the dependence of the total electronic energy and its Kohn–Sham components on the magnetic field. Results obtained from commonly used density-functional approximations are compared with those obtained from Lieb optimizations based on magnetic-field dependent relaxed coupled-cluster singles-and-doubles (CCSD) and second-order Møller–Plesset (MP2) densities. We show that popular approximate exchange–correlation functionals at the generalized-gradient-approximation (GGA), meta-GGA, and hybrid levels of theory provide a good qualitative description of the electronic energy and its Kohn–Sham components in a magnetic field—in particular, for the diamagnetic molecules. The performance of Hartree–Fock theory, MP2 theory, CCSD theory and BDFT with different exchange–correlation functionals is compared with coupled-cluster singles-doubles-perturbative-triples (CCSD(T)) theory for the perpendicular component of the magnetizability. Generalizations of the TPSS meta-GGA functional to systems in a magnetic field work well—the cTPSS functional, in particular, with a current-corrected kinetic-energy density, performs excellently, providing an accurate and balanced treatment of dia- and paramagnetic systems and outperforming MP2 theory.

Citation

Reimann, S., Borgoo, A., Austad, J., Tellgren, E. I., Teale, A. M., Helgaker, T., & Stopkowicz, S. (2019). Kohn–Sham energy decomposition for molecules in a magnetic field. Molecular Physics, 117(1), 97-109. https://doi.org/10.1080/00268976.2018.1495849

• Journal Article Type: Article
• Acceptance Date: Jun 19, 2018
• Online Publication Date: Jul 18, 2018
• Publication Date: 2019
• Deposit Date: Jul 4, 2018
• Publicly Available Date: Jul 19, 2019
• Journal: Molecular Physics
• Print ISSN: 0026-8976
• Electronic ISSN: 1362-3028
• Publisher: Taylor and Francis
• Peer Reviewed: Peer Reviewed
• Volume: 117
• Issue: 1
• Pages: 97-109
• DOI: https://doi.org/10.1080/00268976.2018.1495849
• Keywords: electron correlation, density-functional theory, current density-functional theory, magnetic-field density-functional theory, coupled-cluster theory, molecular magnetic properties, strong magnetic fields
• Public URL: https://nottingham-repository.worktribe.com/output/939322
• Publisher URL: https://www.tandfonline.com/doi/full/10.1080/00268976.2018.1495849
• Additional Information: This is an Accepted Manuscript of an article published by Taylor & Francis in Molecular Physics on 18 July 2018, available online: http://www.tandfonline.com/10.1080/00268976.2018.1495849
• Contract Date: Jul 4, 2018