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Title: Real time propagation of the exact two component time-dependent density functional theory

Authors:
 [1]; ORCiD logo [1];  [1]; ORCiD logo [1]; ORCiD logo [1]
  1. Department of Chemistry, University of Washington, Seattle, Washington 98195, USA
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1324365
Grant/Contract Number:
SC0006863
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
The Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 145; Journal Issue: 10; Related Information: CHORUS Timestamp: 2018-03-09 12:28:54; Journal ID: ISSN 0021-9606
Publisher:
American Institute of Physics
Country of Publication:
United States
Language:
English

Citation Formats

Goings, Joshua J., Kasper, Joseph M., Egidi, Franco, Sun, Shichao, and Li, Xiaosong. Real time propagation of the exact two component time-dependent density functional theory. United States: N. p., 2016. Web. doi:10.1063/1.4962422.
Goings, Joshua J., Kasper, Joseph M., Egidi, Franco, Sun, Shichao, & Li, Xiaosong. Real time propagation of the exact two component time-dependent density functional theory. United States. doi:10.1063/1.4962422.
Goings, Joshua J., Kasper, Joseph M., Egidi, Franco, Sun, Shichao, and Li, Xiaosong. Tue . "Real time propagation of the exact two component time-dependent density functional theory". United States. doi:10.1063/1.4962422.
@article{osti_1324365,
title = {Real time propagation of the exact two component time-dependent density functional theory},
author = {Goings, Joshua J. and Kasper, Joseph M. and Egidi, Franco and Sun, Shichao and Li, Xiaosong},
abstractNote = {},
doi = {10.1063/1.4962422},
journal = {The Journal of Chemical Physics},
number = 10,
volume = 145,
place = {United States},
year = {Tue Sep 13 00:00:00 EDT 2016},
month = {Tue Sep 13 00:00:00 EDT 2016}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1063/1.4962422

Citation Metrics:
Cited by: 7works
Citation information provided by
Web of Science

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  • Mechanism of the ring-opening transformation in the photoexcited crystalline benzene is investigated on the femtosecond scale by a computational method based on the real-time propagation (RTP) time-dependent density functional theory (TDDFT). The excited-state dynamics of the benzene molecule is also examined not only for the distinction between the intrinsic properties of molecule and the intermolecular interaction but for the first validation using the vibration frequencies for the RTP-TDDFT approach. It is found that the vibration frequencies of the excited and ground states in the molecule are well reproduced. This demonstrates that the present method of time evolution using the Suzuki-Trotter-typemore » split operator technique starting with the Franck-Condon state approximated by the occupation change of the Kohn-Sham orbitals is adequately accurate. For the crystalline benzene, we carried out the RTP-TDDFT simulations for two typical pressures. At both pressures, large swing of the C-H bonds and subsequent twist of the carbon ring occurs, leading to tetrahedral (sp{sup 3}-like) C-H bonding. The {nu}{sub 4} and {nu}{sub 16} out-of-plane vibration modes of the benzene molecule are found mostly responsible for these motions, which is different from the mechanism proposed for the thermal ring-opening transformation occurring at higher pressure. Comparing the results between different pressures, we conclude that a certain increase of the intermolecular interaction is necessary to make seeds of the ring opening (e.g., radical site formation and breaking of the molecular character) even with the photoexcitation, while the hydrogen migration to fix them requires more free volume, which is consistent with the experimental observation that the transformation substantially proceeds on the decompression.« less
  • We investigate the Rabi oscillations of electrons excited by an applied electric field in several simple molecular systems using time-dependent configuration interaction (TDCI) and real-time time-dependent density-functional theory (RT-TDDFT) dynamics. While the TDCI simulations exhibit the expected single-electron Rabi oscillations at a single resonant electric field frequency, Rabi oscillations in the RT-TDDFT simulations are a two-electron process. The existence of two-electron Rabi oscillations is determined both by full population inversion between field-free molecular orbitals and the behavior of the instantaneous dipole moment during the simulations. Furthermore, the Rabi oscillations in RT-TDDFT are subject to an intensity threshold of the electricmore » field, below which Rabi oscillations do not occur and above which the two-electron Rabi oscillations occur at a broad range of frequencies. It is also shown that at field intensities near the threshold intensity, the field frequency predicted to induce Rabi oscillations by linear response TDDFT only produces detuned Rabi oscillations. Instead, the field frequency that yields the full two-electron population inversion and Rabi oscillation behavior is shown to be the average of single-electron transition frequencies from the ground S{sub 0} state and the doubly-excited S{sub 2} state. The behavior of the two-electron Rabi oscillations is rationalized via two possible models. The first model is a multi-photon process that results from the electric field interacting with the three level system such that three level Rabi oscillations may occur. The second model suggests that the mean-field nature of RT-TDDFT induces paired electron propagation.« less
  • “Spin-forbidden” transitions are calculated for an eight-membered set of iridium-containing candidate molecules for organic light-emitting diodes (OLEDs) using two-component time-dependent density functional theory. Phosphorescence lifetimes (obtained from averaging over relevant excitations) are compared to experimental data. Assessment of parameters like non-distorted and distorted geometric structures, density functionals, relativistic Hamiltonians, and basis sets was done by a thorough study for Ir(ppy){sub 3} focussing not only on averaged phosphorescence lifetimes, but also on the agreement of the triplet substate structure with experimental data. The most favorable methods were applied to an eight-membered test set of OLED candidate molecules; Boltzmann-averaged phosphorescence lifetimes weremore » investigated concerning the convergence with the number of excited states and the changes when including solvent effects. Finally, a simple model for sorting out molecules with long averaged phosphorescence lifetimes is developed by visual inspection of computationally easily achievable one-component frontier orbitals.« less
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  • We propose a novel analysis of real-time (RT) time-dependent Hartree–Fock and time-dependent density functional theory (TDHF/TDDFT) calculations using a short-time Fourier transform (STFT) technique. RT-TDHF/TDDFT calculations of model dimers were carried out and analyzed using the STFT technique, in addition to the usual Fourier transform (FT). STFT analysis revealed that the induced polarization propagated between the molecules through the intermolecular interaction; that is, it directly showed the electron dynamics of the excited system. The dependence of the propagation period on the intermolecular distance of the dimer was investigated. We also proved the possibility of describing, not just the valence, butmore » also the core excitations by FT analysis of the RT-TDHF/TDDFT calculations of a formaldehyde monomer with Gaussian basis functions compared with conventional TDHF/TDDFT results.« less