Ab initio quantum study of UV absorption spectra of cis- and trans-hexatriene

作者：Komainda A; Zech A; Koeppel H^*

来源：Journal of Molecular Spectroscopy, 2015, 311: 25-35.

DOI：10.1016/j.jms.2014.12.022

• Hexatriene
• Photodynamics
• Internal conversion
• Absorption spectrum
• CASPT2 calculations
• MRCI calculations
• MCTDH

The vibronic structure of the UV-absorption spectra of cis- and trans-hexatriene is revisited in a comparative theoretical investigation. The multidimensional potential energy surfaces of the relevant (1)A(1) (Ag-1) and B-1(2) (B-1(u).) electronic states are obtained from CASPT2 and MRCI ab initio calculations using carefully chosen CAS-spaces. These provide the basis for subsequent wavepacket dynamical calculations for the coupled electronic states carried out with the multiconfiguration time-dependent Hartree scheme. The experimental spectra in the similar to 5 eV energy range are well reproduced for both isomers. The influence of the various degrees of freedom is assessed by comparing the results for different dimensionalities of the calculations. The implications of these findings for the photophysical properties (fluorescence dynamics) are discussed.

• 出版日期2015-5