超冷分子的研究和制备，必须首先确定分子的内部结构和相互作用，即分子的势能曲线和光谱特征，包括电子态、振转能级、超精细结构等。本项目针对同核和异核碱金属双原子分子超精细结构进行系统深入研究，建立模型分析计算K2、Cs2、6Li7Li、85Rb87Rb、NaCs等超精细结构及其光谱，理解耦合情形、微扰、碰撞等对超精细结构的影响，总结同核和异核碱金属分子超精细结构的主要作用项和变化规律，掌握非极性和极性分子内部相互作用的强弱情况和耦合机制，建立碱金属分子超精细结构研究分析和模拟计算的一般方法。同时研究碱金属分子超精细结构随核间距的变化行为，比对基于不同Hund耦合情形的计算结果，与传统热分子光谱（平衡核间距附近）和冷分子光谱（解离限附近）进行比较，揭示同核和异核碱金属分子超精细结构的特点和一般规律，为精密测量、冷原子分子等提供精确的分子势能和能级信息，探讨对偶极量子气体进行操控的新方法和手段。

The study and formation of the ultracold molecule, depends on the molecular structure and internal interaction, i.e. molecular potential curve and spectroscopic characteristics, including the information about excited states, rovibrational energy levels, hyperfine structure, etc. Our research subject is to perform a systematic and in-depth study on the hyperfine structure and its spectroscopy of homonuclear and heteronuclear alkali diatomic molecules, build a theoretical model to analyze and calculate the hyperfine structure and related spectroscopy of K2, Cs2, 6Li7Li, 85Rb87Rb, NaCs, etc., understand the effects of coupling cases, perturbation, collisions, etc. on the hyperfine structure, summarize the dominant interaction and variation rule of the hyperfine structure of homonuclear and heteronuclear alkali diatomic molecules, grasp the power information and coupling mechanism of internal interactions of nonpolar and polar alkali molecules, and establish a general method to analyze and simulate the hyperfine structure of alkali diatomic molecules. Meanwhile, Our research will cover to study the varying behavior of the hyperfine structure of alkali diatomic molecules with the change of the nuclear separation, contrast calculation results from different Hund's coupling cases, compare the calculations with the experimental data from traditional thermal molecular spectroscopy (near equilibrium of the internuclear distance) and cold molecular spectroscopy (near dissociation limit), reveal the characteristics and general rule of the hyperfine structure of alkali diatomic molecules, supply accurate information about molecular potential and energy levels for the precision measurement, cold atom and molecule, etc., and discuss new methods to manipulate the dipolar quantum gas.