2016/05/31 by Kai Luo, Johanna I. Fuks, Neepa T. Maitra · 24 citations
Mathematics · Physics and Astronomy · #Advanced Chemical Physics Studies #Density functional theory #Laser-Matter Interactions and Applications #Mathematics #Physics #Quantum mechanics #Spectroscopy and Quantum Chemical Studies #Statistical physics #Time-dependent density functional theory #physics.chem-ph
paper · pdf · doi:10.1063/1.4955447
published in The Journal of Chemical Physics 145(4), 044101 (American Institute of Physics) · 16 pages, 10 figs
arxiv created 2016/07/13 · openalex publication_date 2016/07/25 · arxiv updated 2016/08/24 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
Adiabatic approximations in time-dependent density functional theory (TDDFT) will in general yield unphysical time-dependent shifts in the resonance positions of a system driven far from its ground-state. This spurious time-dependence is explained in Fuks et al. [Phys. Rev. Lett. 114, 183002 (2015)] in terms of the violation of an exact condition by the non-equilibrium exchange-correlation kernel of TDDFT. Here we give details on the derivation and discuss reformulations of the exact condition that apply in special cases. In its most general form, the condition states that when a system is left in an arbitrary state, the TDDFT resonance position for a given transition in the absence of time-dependent external fields and ionic motion is independent of the state. Special cases include the invariance of TDDFT resonances computed with respect to any reference interacting stationary state of a fixed potential, and with respect to any choice of appropriate stationary Kohn-Sham reference state. We then present several case studies, including one that utilizes the adiabatically exact approximation, that illustrate the conditions and the impact of their violation on the accuracy of the ensuing dynamics. In particular, charge-transfer across a long-range molecule is hampered, and we show how adjusting the frequency of a driving field to match the time-dependent shift in the charge-transfer resonance frequency results in a larger charge transfer over time.