title: Resonance Raman and vibronic absorption spectra with Duschinsky rotation from a time-dependent perspective: application to β-carotene.
abstract: The time-dependent approach to electronic spectroscopy, as popularized by Heller and co-workers in the 1980s, is applied here in conjunction with linear-response, time-dependent density functional theory to study vibronic absorption and resonance Raman spectra of β-carotene, with and without a solvent. Two-state models, the harmonic and the Condon approximations are used in order to do so. A new code has been developed which includes excited state displacements, vibrational frequency shifts, and Duschinsky rotation, i.e., mode mixing, for both non-adiabatic spectroscopies. It is shown that Duschinsky rotation has a pronounced effect on the resonance Raman spectra of β-carotene. In particular, it can explain a recently found anomalous behaviour of the so-called ν(1) peak in resonance Raman spectra [N. Tschirner, M. Schenderlein, K. Brose, E. Schlodder, M. A. Mroginski, C. Thomsen, and P. Hildebrandt, Phys. Chem. Chem. Phys. 11, 11471 (2009)], which shifts with the change in excitation wavelength.
authors.affiliation: Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam-Golm, Germany.
authors.forename: Shiladitya
authors.initials: S
authors.lastname: Banerjee
authors.forename: Dominik
authors.initials: D
authors.lastname: Kröner
authors.forename: Peter
authors.initials: P
authors.lastname: Saalfrank