C_4^(2+)分子的T(?)e系统的Jahn-Teller效应与各向异性现象

The Jahn-Teller effect and the anisotropic phenomena of the T(?)e system for C_4^(2+)molecules

依据Jahn-Teller效应理论与量子理论,利用群论和对称性分析的方法探讨了具有T_d对称性构型的C_4^(2+)分子的T(?)e系统的Jahn-Teller效应与各向异性问题.构建了T(?)e系统的电声耦合哈密顿量,借助么正平移变换求出了系统的基态与激发态及其能量.结果发现,由于电声耦合作用的缘故,系统发生了Jahn-Teller畸变,畸变导致在系统的势能面上形成了3个具有D_(2d)对称性的势阱.无论系统处在哪一个势阱中,系统原初三重简并的能级都将分裂为两条能级.畸变还导致C_4^(2+)分子从T_d对称性降低到D_(2d)对称性,同时C_4^(2+)分子的振动频率发生分解,而频率的分解致使C_4^(2+)分子的各向同性遭到破坏而呈现出各向异性.

Based on Jahn-Teller effect theory and quantum theory, the Jahn-Teller effect and the anisotropy of the T×e system for C4Z＋ molecules with T×e symmetry are studied in this paper using the methods of group theory and symmetry analyses. The Hamiltonian of the T e system is constructed. The ground states and their energy of the system in each minimum are obtained with the help of unity shift transformation, and the corresponding excited states and their energy are also calculated further. It is found that there are three potential energy minima on the potential energy surface of the system. No matter which minimum the system is in, the original ground electronic energy level of the system is split into two energy levels. The Jahn-Teller distortion should cause that the symmetry of C24＋molecules is lowered to C24＋from T×e, and the vibration frequency of C24＋ molecules are split. After the distortion, the isotropy of C24＋molecules is destroyed and its anisotropy should appear.