NH自由基基态及低激发态从头算研究

Ab initio study of ground and low excited states of NH radical

摘要:

本文用耦合簇理论中的CCSD(T)方法和二次组态相互作用中的QCISD(T)方法并结合aug-cc-pv5z基组对NH自由基的基态和激发态进行从头计算研究. 我们拟合出了NH自由基基态和低激发态的势能函数, 以得到势能函数为基础计算出了NH自由基相应态的光谱常数, 并与实验值进行比较, 发现误差比较小; 通过求解NH自由基基态及激发态的径向Schrödinger方程, 得到了NH自由基在转动量子数J=0时基态及低激发态的振动能级及离心畸变常数.

Abstract:

We study the ground state and low excited states of NH radical by using the CCSD(T) method in the coupled cluster theory and the secondary configuration interaction QCISD(T) method combined with the aug-cc- pv5z basis set. The potential energy functions of the ground and excited states of NH radical were fitted. The spectroscopic constants of the corresponding states of NH radical were calculated based on the potential energy function, and compared with the experimental values, the error was found to be small. By solving the radial Schrödinger equation of the ground and excited states of NH radical, the vibrational energy levels and centrifugal distortion constants of the ground and excited states of NH radical at the rotating quantum number J=0 are obtained.