CH2(X^3B1)的分子结构与分析势能函数  

Analytical potential energy function for the ground state (X^3B_1) of CH_2

作　　者：阮文[1] 罗文浪[1] 张莉[1] 朱正和[1] 

机构地区：[1]四川大学原子与分子物理研究所

出　　处：《四川大学学报（自然科学版）》2008年第1期137-142,共6页Journal of Sichuan University(Natural Science Edition)

基　　金：国家自然科学基金联合基金(NSAF10676022)

摘　　要：基于B3p86/aug-cc-pvtz方法,优化出CH2分子的基态为C2v(~X3B1),其平衡几何为Re=1.0774,∠HCH=134.958°,离解能De=8.682 eV,此结论与有关文献有很大的差异.在此基础上,根据微观可逆性原则,正确地判断了离解极限.使用多体项展式理论方法,首次导出了基态CH2(~X3B1)分子的分析势能函数,该势能表面准确地再现了其平衡结构,然后根据势能函数等值图,讨论了H+CH反应和C+H2反应的势能面静态特征.结果表明:在H+CH→CH2通道上反应为无阈能反应,而C+H2通道上存在两种可能性:即有可能形成CH2复合体,也有可能发生交换反应形成H+CH,该反应阈能为1.7095 eV or 39.42 Kcal/mol.Based on group theory and atomic and molecular reactive statics （AMIRS）, the dissociation limits of CH2 are determined. The present work discovers that for CH2 the ground state is C2v with X ^3B1, its equilibrium geometry Re = 1. 0774A and ∠HCH= 134.96°, and dissociation energy De =8. 682 eV, this result israther different from relevent references, which indicated that the ground state is linear with X^3∑g^-. Then, analytical potential energy function for the ground state （X^3B1） of CH2 has been derived for first time using many-body expansion method. From this potential energy function, it is obvious to see that the reactive channel H ＋ CH→CH2 is without threshold energy for its radical reaction, and the channel C ＋ H2 would have two possibilities, i. e. to form complex CH2 or exchange reaction H ＋ CH, the threshold energy is about 1. 7095 eV or 39.42 Kcal/mol.

关 键 词：基态CH2 多体项展式理论 分析势能函数 

分 类 号：O561.1[理学—原子与分子物理]