TY  - INPR
A1  - Titov, Evgenii
A1  - Humeniuk, Alexander
A1  - Mitric, Roland
T1  - Comparison of moving and fixed basis sets for nonadiabatic quantum dynamics at conical intersections
T2  - Chemical Physics
N2  - We assess the performance of two different types of basis sets for nonadiabatic quantum dynamics at conical intersections. The basis sets of both types are generated using Ehrenfest trajectories of nuclear coherent states. These trajectories can either serve as a moving (time-dependent) basis or be employed to sample a fixed (time-independent) basis. We demonstrate on the example of two-state two-dimensional and three-state five-dimensional models that both basis set types can yield highly accurate results for population transfer at intersections, as compared with reference quantum dynamics. The details of wave packet evolutions are discussed for the case of the two-dimensional model. The fixed basis is found to be superior to the moving one in reproducing nonlocal spreading and maintaining correct shape of the wave packet upon time evolution. Moreover, for the models considered, the fixed basis set outperforms the moving one in terms of computational efficiency.
KW  - Nonadiabatic quantum dynamics
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-199225
UR  - https://doi.org/10.1016/j.chemphys.2019.110526
N1  - Submitted version
ER  - 
TY  - INPR
A1  - Titov, Evgenii
A1  - Humeniuk, Alexander
A1  - Mitric, Roland
T1  - Comparison of moving and fixed basis sets for nonadiabatic quantum dynamics at conical intersections
T2  - Chemical Physics
N2  - We assess the performance of two different types of basis sets for nonadiabatic quantum dynamics at conical intersections. The basis sets of both types are generated using Ehrenfest trajectories of nuclear coherent states. These trajectories can either serve as a moving (time-dependent) basis or be employed to sample a fixed (time-independent) basis. We demonstrate on the example of two-state two-dimensional and three-state five-dimensional models that both basis set types can yield highly accurate results for population transfer at intersections, as compared with reference quantum dynamics. The details of wave packet evolutions are discussed for the case of the two-dimensional model. The fixed basis is found to be superior to the moving one in reproducing true nonlocal spreading and maintaining correct shape of the wave packet upon time evolution. Moreover, for the models considered, the fixed basis set outperforms the moving one in terms of computational efficiency.
KW  - Nonadiabatic quantum dynamics
Y1  - 2020
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-198699
UR  - https://doi.org/10.1016/j.chemphys.2019.110526
N1  - Accepted manuscript
ER  - 
TY  - INPR
A1  - Titov, Evgenii
A1  - Humeniuk, Alexander
A1  - Mitric, Roland
T1  - Exciton localization in excited-state dynamics of a tetracene trimer: A surface hopping LC-TDDFTB study
T2  - Physical Chemistry Chemical Physics
N2  - Excitons in the molecular aggregates of chromophores are key participants in important processes such as photosynthesis or the functioning of organic photovoltaic devices. Therefore, the exploration of exciton dynamics is crucial. Here we report on exciton localization during excited-state dynamics of the recently synthesized tetracene trimer [Liu et al., Org. Lett., 2017, 19, 580]. We employ the surface hopping approach to nonadiabatic molecular dynamics in conjunction with the long-range corrected time-dependent density functional tight binding (LC-TDDFTB) method [Humeniuk and Mitrić, Comput. Phys. Commun., 2017, 221, 174]. Utilizing a set of descriptors based on the transition density matrix, we perform comprehensive analysis of exciton dynamics. The obtained results reveal an ultrafast exciton localization to a single tetracene unit of the trimer during excited-state dynamics, along with exciton transfer between units.
KW  - Exciton dynamics
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-198680
UR  - https://doi.org/10.1039/C8CP05240A
N1  - Accepted Manuscript
ER  -