TY  - JOUR
A1  - Plötz, Per-Arno
A1  - Megow, Jörg
A1  - Niehaus, Thomas
A1  - Kühn, Oliver
T1  - All-DFTB Approach to the Parametrization of the System-Bath Hamiltonian Describing Exciton-Vibrational Dynamics of Molecular Assemblies
T2  - Journal of chemical theory and computation
N2  - Spectral density functions are central to the simulation of complex many body systems. Their determination requires making approximations not only to the dynamics but also to the underlying electronic structure theory. Here, blending different methods bears the danger of an inconsistent description. To solve this issue we propose an all-DFTB approach to determine spectral densities for the description of Frenkel excitons in molecular assemblies. The protocol is illustrated for a model of a PTCDI crystal, which involves the calculation of monomeric excitation energies and Coulomb couplings between monomer transitions, as well as their spectral distributions due to thermal fluctuations of the nuclei. Using dynamically defined normal modes, a mapping onto the standard harmonic oscillator spectral densities is achieved.
Y1  - 2018
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/51833
SN  - 1549-9618
SN  - 1549-9626
VL  - 14
IS  - 10
SP  - 5001
EP  - 5010
PB  - American Chemical Society
CY  - Washington
ER  -