Identification and Resolution of Unphysical Multielectron Excitations in the Real-Time Time-Dependent Kohn-Sham Formulation
Type
ArticleKAUST Department
Computational Physics and Materials Science (CPMS)Material Science and Engineering Program
Physical Science and Engineering (PSE) Division
Date
2020-01-15Submitted Date
2019-05-01Permanent link to this record
http://hdl.handle.net/10754/661416
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We resolve a fundamental issue associated with the conventional Kohn-Sham formulation of real-time time-dependent density functional theory. We show that unphysical multielectron excitations, generated during time propagation of the Kohn-Sham equations due to fixation of the total number of Kohn-Sham orbitals and their occupations, result in incorrect electron density and, therefore, wrong predictions of physical properties. A new formulation is proposed in that the number of Kohn-Sham orbitals and their occupations are updated on the fly, the unphysical multielectron excitations are removed, and the correct electron density is determined. The correctness of the new formulation is demonstrated by simulations of Rabi oscillation, as analytical results are available for comparison in the case of noninteracting electrons.Citation
Zang, X., Schwingenschlögl, U., & Lusk, M. T. (2020). Identification and Resolution of Unphysical Multielectron Excitations in the Real-Time Time-Dependent Kohn-Sham Formulation. Physical Review Letters, 124(2). doi:10.1103/physrevlett.124.026402Publisher
American Physical Society (APS)Journal
Physical Review LettersarXiv
1912.10676Additional Links
https://link.aps.org/doi/10.1103/PhysRevLett.124.026402http://arxiv.org/pdf/1912.10676
ae974a485f413a2113503eed53cd6c53
10.1103/PhysRevLett.124.026402