Kanakati Arun Kumar, Mahapatra S
School of Chemistry, University of Hyderabad, Hyderabad 500 046, India.
J Chem Phys. 2021 Feb 7;154(5):054313. doi: 10.1063/5.0039923.
Nuclear dynamics in the first six vibronically coupled electronic states of pentafluorobenzene radical cation is studied with the aid of the standard vibronic coupling theory and quantum dynamical methods. A model 6 × 6 vibronic Hamiltonian is constructed in a diabatic electronic basis using symmetry selection rules and a Taylor expansion of the elements of the electronic Hamiltonian in terms of the normal coordinate of vibrational modes. Extensive ab initio quantum chemistry calculations are carried out for the adiabatic electronic energies to establish the diabatic potential energy surfaces and their coupling surfaces. Both time-independent and time-dependent quantum mechanical methods are employed to perform nuclear dynamics calculations. The vibronic spectrum of the electronic states is calculated, assigned, and compared with the available experimental results. Internal conversion dynamics of electronic states is examined to assess the impact of various couplings on the nuclear dynamics. The impact of increasing fluorination of the parent benzene radical cation on its radiative emission is examined and discussed.
借助标准的振动电子耦合理论和量子动力学方法，研究了五氟苯自由基阳离子前六个振动电子耦合电子态中的核动力学。利用对称选择规则和电子哈密顿量元素在振动模式的正常坐标方面的泰勒展开，在非绝热电子基中构建了一个6×6的振动哈密顿量模型。对绝热电子能量进行了广泛的从头算量子化学计算，以建立非绝热势能面及其耦合面。采用与时间无关和与时间有关的量子力学方法进行核动力学计算。计算并指定了电子态的振动光谱，并与现有的实验结果进行了比较。研究了电子态的内转换动力学，以评估各种耦合对核动力学的影响。研究并讨论了母体苯自由基阳离子氟化程度增加对其辐射发射的影响。
