We develop a methodology for extracting the Kohn-Sham angular momentum of excitons in realistic systems from time-dependent density functional theory. For small systems the exciton populations can be calculated analytically, which allows us to test the methodology for a three-arm H2 molecular ring and a pair of such rings. For larger systems the developed methodology opens a venue to determine the angular momentum of excitons by first principles calculations. A chain of twenty three-arm H2 molecular rings and a triphenylphosphine molecule are investigated as illustrative examples. It is demonstrated that the angular momentum is conserved during the absorption of twisted light.
|Original language||English (US)|
|Journal||Physical Review B|
|State||Published - Jul 15 2019|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The authors thank Prof. Mark T. Lusk for helpful discussions. The research reported in this publication was supported by funding from King Abdullah University of Science and Technology (KAUST). For computer time, this research used the resources of the Supercomputing Laboratory at KAUST.