Disentanglement of triplet and singlet states of azobenzene: direct EELS detection and QMC modeling

被引:21
作者
Dubecky, M. [1 ]
Derian, R. [1 ]
Horvathova, L. [1 ]
Allan, M. [2 ]
Stich, I. [1 ]
机构
[1] Slovak Acad Sci, Inst Phys, Ctr Computat Mat Sci, Bratislava 84511, Slovakia
[2] Univ Fribourg, Dept Chem, CH-1700 Fribourg, Switzerland
基金
瑞士国家科学基金会;
关键词
QUANTUM MONTE-CARLO; LOWEST ELECTRONIC STATES; CIS-TRANS ISOMERIZATION; AB-INITIO CALCULATION; WAVE-FUNCTIONS; PHOTOISOMERIZATION; SPECTRA; ABSORPTION; SPECTROSCOPY; SIMULATIONS;
D O I
10.1039/c1cp22520k
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Singlet and triplet excited states of trans-azobenzene have been measured in the gas phase by electron energy loss spectroscopy (EELS). In order to interpret the strongly overlapping singlet and triplet bands in the spectra a set of large-scale correlated quantum Monte-Carlo (QMC) simulations was performed. The EELS/QMC combination of methods yields an excellent agreement between theory and experiment and for the two low-lying excited singlet and two low-lying triplet states permitted their unambiguous assignment. In addition, EELS revealed two overlapping electronic states in the band commonly assigned as S-2, the lower one with a pronounced vibrational structure, the upper one structureless. Finally, the agreement between theory and experiment was shown to further increase by taking computationally into account the finite temperature effects.
引用
收藏
页码:20939 / 20945
页数:7
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