As_2H、AsH和As_2分子的结构与势能函数

采用Gaussian09程序,运用密度泛函B3LYP方法,在6-311＋＋g（3df,3pd）基组水平下,对As2、AsH与As2H分子的结构进行优化和频率计算,得到了它的平衡几何构型和力常数,理论计算结果与实验值接近。As2H（X2A′）分子的最稳定结构为三角形的Cs结构,离解能是8.9 eV。在AsH（X3∑-）和As2（X1∑g＋）的Murrell-Sor-bie势能函数基础上,并采用多体项展式理论导出了基态As2H（X2A′）分子的解析势能函数,其等值势能图准确再现了基态As2H（X2A′）分子的结构特征及势阱深度与位置。

Structures and Potential Energy Functions of As2, AsH and As2H Molecules

Density function methods B3LYP with the basis set 6-311＋＋g（3df,3pd）have been used to optimize the structures of As2,AsH and As2H molecule.The balanced geometric configuration and mechanical absolute were obtained,and the result calculated by theory was almost the same as that of the experiment.The most stable molecular structure As2H（X2A′） were Cs structure with triangle,segregation ability was 8.9eV.The potential energy curves of As2（X1∑＋g） and AsH（X3∑-） were derived.For the ground state of As2H（X2A′）,the analytic potential energy function has been derived by the many-body expansion theory,whose equivalent potential energy successfully describes its molecular structural characteristics of ground state of As2H（X2A′） and the dissociation.