中文摘要：

采用Gaussian 98程序,运用B3LYP方法,对Pd和Pb原子采用收缩价基组LANL2DZ,对Pb2和PdPb2分子的微观结构进行了理论计算.由于Pb2分子离解后一个Pb原子处于基态,另一个Pb原子处于激发态,采用最小二乘法拟合Pb2分子的势能函数,选用的函数形式为Murrell-Sorbie势能函数加上开关函数.使用多体展式理论导出了势函数中的参数进而给出PdPb2分子基态势函数的解析表达式,其势能面准确地复现了PdPb2分子的两个稳定构型（C2V和C∞v）及其能量关系.

英文摘要：

Density function method （B3LYP） has been used to optimize the possible structures of Pb2 and PdPb2 molecules by basis set （LANL2DZ） for Pd and Pb atoms. The Murrell-Sorbie potential energy function of Pb2 molecule has been fitted through the least square fitting, and the potential energy function of PdPb2 is given by many-body expansion theory. The potential energy contours describe the structure character of PdPb2 ground state molecule rightly. Furthermore, molecular static reaction pathway based on this potential energy function is investigated.