本文应用相对论赝势从头计算方法,在不同基组水平上,系统地研究了卤化汞(HgX_2,X=Cl,Br,I)系列的电子结构。表明除Hg的6s主要参与成键外,5dz~2也起了重要的作用。并且随卤素原子序的增加,π成键作用也增强。同时还应用单电子自旋-轨道耦合方法,研究了旋-轨耦合效应的影响,并指定了该系列化合物的光电子能谱。 In this paper, we use the ab initio method of relativistic pseudopotential to systematically study the electronic structures of mercury halide (HgX_2, X = Cl, Br, I) series at different levels. The results showed that 5dz ~ 2 played an important role in addition to 6s of Hg. And with the increase of atomic number of halogen, π-bonding effect is also enhanced. At the same time, the effect of spin-orbit coupling effect was also studied by single-electron spin-orbit coupling method, and the photoelectron spectra of the compounds were also assigned.