Kr-CS_2体系势能面及束缚态能级的理论研究

Theoretical study of the potential energy surface and bound state energies for Kr-CS_2 complex

本文采用单双迭代(包括非迭代三重激发)耦合簇CCSD(T)方法,对C、S原子采用aug-ccPVTZ基组,对Kr原子采用cc-PVTZ-DK基组,并且加上中心键函数(3s3p2d2f1g),计算得到Kr-CS_2体系的势能面.该势能面为T型结构,存在一个全局极小值和两个等价的局域极小值.全局极小值位于R=7.05 a0,θ=90°处,势能值为-396.194 cm^(-1).两个局域极小值分别位于R=10.15 a0,θ=0°和180°处,势能为-243.647 cm^(-1).利用该势能面,通过数值求解相应的薛定谔方程,计算得出体系J≤10的束缚态能级及微波谱跃迁频率,并通过跃迁频率拟合得到相应的光谱常数.

The potential energy surface of Kr-CS2 complex was calculated using the coupled-cluster singles and doubles with noniterative inclusion of connected triples [CCSD（T）]. The aug-cc-PVTZ basis sets for C and S and the cc-PVTZ-DK basis set for Kr were used with an additional set of midbond functions （3s3p2d2f1g）. The potential energy surface （PES） has a T-shaped global minimum and two equivalent local linear minima. The global minimum locates at R =7.05 a0, θ= 90°with energy of -396.194 cm-1. The two equivalent local minima with energy of -243.647 cm-1 are located at the linear geometry for R = 10.15a0,θ= 0°and 180°. Based on the PES, the bound state energies up to J≤10 for Kr- CS2 are calculated by solving the Schr？dinger equation. The microwave spectra and the spectroscopic constants were investigated.