SeH_2分子的结构与从头计算  

Structure and potential energy function investigation on SeH_2 molecule

作　　者：蒋利娟[1,2] 王凤产[2] 梁彦天[1] 徐彦[1] 张现周[2] 

机构地区：[1]新乡学院物理系,新乡453003 [2]河南师范大学物理与信息工程学院,新乡453007

出　　处：《四川大学学报（自然科学版）》2011年第1期116-120,共5页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金(10774039);河南省自然科学计划项目(2010C140002);河南省基础与前沿技术研究计划项目(102300410230)

摘　　要：应用密度泛函B3P86方法、基组6—311＋＋G（3d2f）对SeH。分子的基态结构进行优化，优化得到SeH。的稳定构型为C2V，电子态为^1A1，平衡核间距为Re=0．14688nm、键角为∠HseH=90．75332°、离解能为8．8037eV．然后对它们的力常数及谐振频率进行了计算．在推导SeH2的离解极限基础上，应用多体展式理论方法，导出了基态SeH2分子的分析势能函数，该势能表面准确地再现了SeH2分子的结构特征和能量变化．分析讨论得到势能面的静态特征：SeH＋H—SeH2反应为无闽能反应．这些数据为分子反应动力学提供了理论依据．Using the BaP86/6-311＋＋G（3d2f）, the possible ground-state struccures of Sell2 molecule have been used to optimize. The results show that the ground state of SeH2 molecule is of C2v symmetry and of ^1A1 state, whose angle, equilibrium nuclear distance and dissociation energy are 90. 753 3°, 0. 146 88 nm and 8.803 7 eV respectively, and their harmonic frequencies, force constants have been calculated. The present paper correctly determines the dissociation limits, based on group theory and atomic and molecular reactive statics （AMRS）. Analytical potential energy functions for the ground states X1Alo{ Sell2 have been derived using many-body expansion method. The structure and energy of SeHz can cor- rectly reappear on the potential surface. Molecular reaction kinetics of SeH＋ H based on the potential energy functions is discussed briefly.

关 键 词：SeH2 多体项展式理论 势能函数 

分 类 号：O561.1[理学—原子与分子物理]