TY  - JOUR
A1  - Plötz, Per-Arno
A1  - Megow, Jörg
A1  - Niehaus, Thomas
A1  - Kühn, Oliver
T1  - Spectral densities for Frenkel exciton dynamics in molecular crystals
T2  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr
N2  - Effects of thermal fluctuations on the electronic excitation energies and intermonomeric Coulomb couplings are investigated for a perylene-tetracarboxylic-diimidecrystal. To this end, time dependent density functional theory based tight binding (TD-DFTB) in the linear response formulation is used in combination with electronic ground state classical molecular dynamics. As a result, a parametrized Frenkel exciton Hamiltonian is obtained, with the effect of exciton-vibrational coupling being described by spectral densities. Employing dynamically defined normal modes, these spectral densities are analyzed in great detail, thus providing insight into the effect of specific intramolecular motions on excitation energies and Coulomb couplings. This distinguishes the present method from approaches using fixed transition densities. The efficiency by which intramolecular contributions to the spectral density can be calculated is a clear advantage of this method as compared with standard TD-DFT. Published by AIP Publishing.
Y1  - 2017
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/55305
SN  - 0021-9606
SN  - 1089-7690
VL  - 146
PB  - American Institute of Physics
CY  - Melville
ER  -