Non-perturbative calculation of molecular magnetic properties within current-density functional theory

Tellgren, Erik I.; Teale, Andrew M.; Furness, James W.; Lange, K.K.; Ekstr�m, Ulf; Helgaker, Trygve

Abstract

We present a novel implementation of Kohn-Sham density-functional theory utilizing London atomic orbitals as basis functions. External magnetic elds are treated non-perturbatively, which enables the study of both magnetic response properties and the effects of strong fields, using either standard density functionals or current-density functionals - the implementation is the first fully self-consistent implementation of the latter for molecules. Pilot applications are presented for the finite-field calculation of molecular magnetizabilities, hypermagnetizabilities and nuclear magnetic resonance shielding constants, focusing on the impact of current-density functionals on the accuracy of the results. Existing current-density functionals based on the gauge-invariant vorticity are tested and found to be sensitive to numerical details of their implementation. Furthermore, when appropriately regularized, the resulting magnetic properties show no improvement over standard density-functional results. An advantage of the present implementation is the ability to apply density-functional theory to molecules in very strong magnetic fields, where the perturbative approach breaks down. Comparison with high accuracy full-conguration-interaction results shows that the inadequacies of current-density approximations are exacerbated with increasing magnetic field strength. Standard density-functionals remain well behaved but fail to deliver high accuracy. The need for improved current-dependent density-functionals, and how they may be tested using the presented implementation, is discussed in light of our findings.

Citation

Tellgren, E. I., Teale, A. M., Furness, J. W., Lange, K., Ekström, U., & Helgaker, T. (2014). Non-perturbative calculation of molecular magnetic properties within current-density functional theory. Journal of Chemical Physics, 140(3), https://doi.org/10.1063/1.4861427

• Journal Article Type: Article
• Publication Date: Jan 15, 2014
• Deposit Date: Dec 17, 2015
• Publicly Available Date: Dec 17, 2015
• Journal: Journal of Chemical Physics
• Print ISSN: 0021-9606
• Electronic ISSN: 1089-7690
• Publisher: American Institute of Physics
• Peer Reviewed: Peer Reviewed
• Volume: 140
• Issue: 3
• DOI: https://doi.org/10.1063/1.4861427
• Public URL: https://nottingham-repository.worktribe.com/output/721757
• Publisher URL: http://scitation.aip.org/content/aip/journal/jcp/140/3/10.1063/1.4861427
• Additional Information: This is the peer reviewed version of the following article: E. I. Tellgren, A. M. Teale, J. W. Furness, K. K. Lange, U. Ekström, and T. Helgaker, The Journal of Chemical Physics 140, 034101 (2014), American Institute of Physics