Petrenko Taras, Rauhut Guntram
Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, 70569 Stuttgart, Germany.
J Chem Phys. 2020 Mar 21;152(11):114109. doi: 10.1063/5.0003272.
The time-independent eigenstate-free Raman wavefunction approach for calculating anharmonic vibronic spectra has been extended for the calculation of Herzberg-Teller contributions on the basis of an n-mode expansion of the transition electric dipole moment surface. This allows for the efficient simulation of Franck-Condon dark vibronic spectra. In addition, vibrational angular momentum terms have been implemented into this formalism, as they are important for an accurate description of vibrational wavefunctions spanning double-well potentials. This approach has been used to compute the FC-forbidden vibronic spectrum of the n → π transition of formaldehyde based on a potential energy and transition dipole moment surfaces obtained from explicitly correlated multi-reference configuration interaction calculations. An extensive analysis of the resulting vibronic structure is provided, which allows for a detailed assignment and interpretation of the experimental spectrum.
用于计算非谐振动电子光谱的与时间无关的无本征态拉曼波函数方法，已基于跃迁电偶极矩面的n模展开进行扩展，以计算赫兹伯格-泰勒贡献。这使得能够高效模拟弗兰克-康登暗振动电子光谱。此外，振动角动量项已被纳入该形式体系，因为它们对于精确描述跨越双阱势的振动波函数很重要。该方法已用于基于从显式相关多参考组态相互作用计算获得的势能和跃迁偶极矩面，计算甲醛n→π跃迁的弗兰克-康登禁阻振动电子光谱。对所得振动电子结构进行了广泛分析，从而能够对实验光谱进行详细归属和解释。
