A simple one-electron expression for electron rotational factors

Tian Qiu; Mansi Bhati; Zhen Tao; Xuezhi Bian; Jonathan Rawlinson; Robert G Littlejohn; Joseph E Subotnik

doi:10.1063/5.0192083

A simple one-electron expression for electron rotational factors

J Chem Phys. 2024 Mar 28;160(12):124102. doi: 10.1063/5.0192083.

Authors

Tian Qiu¹, Mansi Bhati¹, Zhen Tao¹, Xuezhi Bian¹, Jonathan Rawlinson², Robert G Littlejohn³, Joseph E Subotnik¹

Affiliations

¹ Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
² Department of Mathematics, University of Manchester, Manchester M13 9PL, United Kingdom.
³ Department of Physics, University of California, Berkeley, California 94720, USA.

PMID: 38526113
DOI: 10.1063/5.0192083

Abstract

Within the context of fewest-switch surface hopping (FSSH) dynamics, one often wishes to remove the angular component of the derivative coupling between states J and K. In a previous set of papers, Shu et al. [J. Phys. Chem. Lett. 11, 1135-1140 (2020)] posited one approach for such a removal based on direct projection, while we isolated a second approach by constructing and differentiating a rotationally invariant basis. Unfortunately, neither approach was able to demonstrate a one-electron operatorÔ whose matrix element JÔK was the angular component of the derivative coupling. Here, we show that a one-electron operator can, in fact, be constructed efficiently in a semi-local fashion. The present results yield physical insight into designing new surface hopping algorithms and are of immediate use for FSSH calculations.