I-IIB族二卤化物低电子态电子结构及光谱常数的耦合簇近似方法研究

考虑旋轨耦合效应后，因电子结构的复杂性和显著的相对论，重元素及超重元素分子体系的计算倍受关注。本项目计划利用含旋轨耦合的耦合簇方法和运动方程耦合簇方法对I-IIB族二卤化物低电子态电子结构及光谱常数进行计算，其核心思想是通过高精度处理旋轨耦合效应，优化重元素及超重元素体系基态及低激发态的平衡构型并计算分裂能、电离能和解离能。研究内容主要包括旋轨耦合效应在闭壳层体系和开壳层体系低电子态计算中的处理方法；近似含旋轨耦合运动方程耦合簇方法以提高电离能的计算效率。本项目是I-IIB族二卤化物理论计算的进一步深化和含旋轨耦合运动方程耦合簇方法的进一步发展，能够提供旋轨耦合效应处理的新思路，推动发展重元素及超重元素体系高效计算的新方法，所得计算结果有助于重元素及超重元素分子体系在医药、催化剂、材料科学等领域的应用。

The calculation of heavy and superheavy element molecules attracts more attention due to the complexity of electronic structure and remarkable relativistic effects after considering spin-orbit coupling (SOC). This project mainly focuses on the electronic structure and spectroscopic constants calculation of low-lying states in group I-IIB dihalides using coupled-cluster method and equation-of-motion coupled-cluster method with SOC. The core idea is that equilibrium geometry, splitting energy, ionization energy and dissociation energy of the ground states and low-lying excited states in heavy and superheavy element molecules will be calculated through the accurate treatment of SOC. One of the main contents is how to deal with SOC when the properties of low-lying states in closed-shell and open-shell molecules are calculated, respectively; the other is that approximating the equation-of-motion coupled-cluster method with SOC to improve the calculation efficiency of ionization energy. This project is the further calculation of group I-IIB dihalides and the development of equation-of-motion coupled-cluster method with SOC. It can provide a new way to deal with SOC calculation and promote the development of new method for efficient calculation of heavy and superheavy element molecules. Furthermore, the results are helpful for the application of heavy and superheavy element molecules in the field of medicine, catalysis, and material science.