Universität Potsdam, Institut für Chemie, Karl-Liebknecht-Straße 24-25, D-14476 Potsdam-Golm, Germany.
J Chem Phys. 2012 Dec 14;137(22):22A534. doi: 10.1063/1.4748147.
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.
20 世纪 80 年代，由 Heller 及其同事推广的时间相关电子光谱方法与线性响应、时间相关密度泛函理论相结合，用于研究β-胡萝卜素的振子吸收和共振拉曼光谱，包括有无溶剂。为此，使用了两态模型，即谐波近似和 Condon 近似。已经开发了一种新的代码，用于两种非绝热光谱，包括激发态位移、振动频率位移和 Duschinsky 旋转，即模式混合。结果表明，Duschinsky 旋转对β-胡萝卜素的共振拉曼光谱有显著影响。特别是，它可以解释最近在共振拉曼光谱中发现的所谓ν(1)峰的异常行为[N. Tschirner, M. Schenderlein, K. Brose, E. Schlodder, M. A. Mroginski, C. Thomsen, and P. Hildebrandt, Phys. Chem. Chem. Phys. 11, 11471 (2009)]，该峰随激发波长的变化而移动。
