Vibrationally resolved UV/Vis spectroscopy with time-dependent density functional based tight binding

R. Ruger (1, 2, 3) , Thomas Niehaus (4) , Lenthe E. Van (1) , T. Heine (3) , L. Visscher (2)

1 Scientific Computing and Modelling N.V.
2 VU - Vrije Universiteit Amsterdam [Amsterdam]
3 Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie
4 ILM - Institut Lumière Matière [Villeurbanne]

We report a time-dependent density functional based tight-binding (TD-DFTB) scheme for the calculation of UV/Vis spectra, explicitly taking into account the excitation of nuclear vibrations via the adiabatic Hessian Franck-Condon method with a harmonic approximation for the nuclear wavefunction. The theory of vibrationally resolved UV/Vis spectroscopy is first summarized from the viewpoint of TD-DFTB. The method is benchmarked against time-dependent density functional theory (TD-DFT) calculations for strongly dipole allowed excitations in various aromatic and polar molecules. Using the recent 3ob:freq parameter set of Elstner’s group, very good agreement with TD-DFT calculations using local functionals was achieved.

Domaines: Chimie; Physique [physics]; Sciences de l'ingénieur [physics]

R. Ruger, Thomas Niehaus, Lenthe E. Van, T. Heine, L. Visscher. Vibrationally resolved UV/Vis spectroscopy with time-dependent density functional based tight binding. Journal of Chemical Physics, 2016, 145, pp.184102. ⟨10.1063/1.4966918⟩. ⟨hal-02290217⟩