【摘要】 应用群论及原子分子反应静力学方法,导出了SiFCl分子的电子态及其离解极限,采用B3P86方法,在CC-PVTZ水平上,对SiFCl基态分子稳定构型优化为单重态的Cs构型,其平衡核间距RSi-F=0.1614nm,RSi-Cl=0.2092nm,∠αClSiF=100.5°,能量为-850.4488 u.同时计算出基态的简正振动频率为:对称伸缩振动频率(υA′)=256.9cm-1,弯曲振动频率υ(A′)=516.4 cm-1和反对称伸缩振动频率(υA′)=845.4cm-1.并在此基础上,作者使用多体项展式理论方法,导出了基态SiFCl分子的全空间解析势能函数,该势能函数能准确地再现SiFCl(Cs)的平衡结构.更多还原

【Abstract】 The equilibrium geometry of SiF,SiCl,FCl and SiFCl molecule have been calculated on the computational levels of density functional theory(DFT).The possible electronic states and reasonable dissociation limits for the ground state of SiF,SiCl,FCl and SiFCl molecules are determined based on atomic and molecular reaction statics.And Murrell-Sorbie analytic potential energy function of SiF,SiCl,FCl molecules have been derived through the least-square fitting to ab initio data.Similarly,the harmonic frequency has been calculated,and the analytic potential energy function of SiFCl molecule has been derived using many-body expansion theory for the first time.更多还原