PCl^n(n=-1,0,+1)分子离子基态的结构与势能函数

The structure and potential energy function for the ground state of the PCl^n(n=-1,0,+1)

基于Gaussian03计算软件,选用高角动量基函数6-311++g(df,pd),分别使用密度泛函理论UB3LYP和UB3P86,以及组态相互作用方法UCCSD-FC和UQCISD-FC,对PCl分子和PCl+,PCl-离子基态进行了几何优化,进一步对其进行了频率计算和单点能扫描计算.用最小二乘法拟合得到了PCln(n=-1,0,+1)分子离子基态的Murrell-Sorbie势能函数.与实验及理论结果比较表明,对PCl,PCl+分子离子基态光谱常数(Be,αe,ωe,ωexe)的计算结果达到了很高的精度.文章还首次给出PCl-分子离子基态光谱参数(Be,αe,ωe,ωexe)和PCln(n=-1,0,+1)力常数(f2,f3,f4)的理论数据,为PCln(n=-1,0,+1)分子离子的更深层次研究和应用提供重要的理论基础.

Based on the Gaussian03 calculation software,the density functional theory UB3LYP and UB3P86,configuration interaction method UCCSD-FC and UQCISD-FC have been used to optimize the possible ground-state structures of PCl molecule,PCl＋ and PCl-molecule ion with the 6-311＋＋g（df,pd） basis sets respectively.Frequency and single-point energy scan for PCln（n=-1,0,＋1） have been calculated.Spectral parameters（Be,αe,ωe,ωeχe） of the PCl molecule and PCl＋ ion ground state are obtained by least square fitting to the Murrell-Sorbie function.The results of calculation are in good agreement with experimental data.In this work,spectral parameters（Be,αe,ωe,ωeχe） of PCl-and force constants（f2,f3,f4） of PCln（n=-1,0,＋1） molecule ion for ground state are shown for the first time.This calculation may provide important theoretical basis for investigation and further study of PCln（n=-1,0,＋1）.