Si_3分子基态(X^1A_1)的结构与分析势能函数  

Structure and analytic potential energy function for ground state of Si_3(X^1A_1) molecule

作　　者：伍冬兰[1] 程新路[1] 杨向东[1] 阮文[1] 谢安东[2] 万慧军[2] 

机构地区：[1]四川大学原子与分子物理研究所,成都610065 [2]井冈山学院数理学院,吉安343009

出　　处：《原子与分子物理学报》2007年第5期937-941,共5页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10376021);江西省教育厅;科技厅科技项目(20073026;200621;2006263);井冈山学院资助项目(JZ0714)

摘　　要：应用群论及原子分子反应静力学方法推导Si分子的电子态及其离解极限,在B3P86/CC-PVTZ水平上,对Si3分子基态进行优化计算,得出Si3基态的单重态能量最低,其稳定构性为的C2V构型,平衡核间距Re=0.2176nm、∠213=79.7°,能量为-869.2057a.u..同时计算出基态的简正振动频率:对称伸缩振动频率ν(B2)=547.6446cm-1,弯曲振动频率ν(A1)=185.6100cm-1和反对称伸缩振动频率ν(A1)=559.6090cm-1.在此基础上,使用多体项展式理论方法,导出了基态Si3分子的全空间解析势能函数,该势能函数准确再现了Si3(C2V)平衡结构.The equilibrium geometry of Si2 and Si3 molecule have been firstly calculated on the computational levels of density functional theory （DFT）. The possible electronic state and reasonable dissociation limit for the ground state of Si3（X^1A1） molecule are determined based on atomic and molecular reaction statics, Murrell-Sorbie analytic potential energy function of Si2 molecule has 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 Si3 molecule is derived by many-body expansion theory for the first time.

关 键 词：Si3 多体项展式理论 全空间解析势能函数 

分 类 号：O561.3[理学—原子与分子物理]