中文摘要：

运用密度泛函（B3LYP）方法，分别选用6-311＋G（3df）和aug-cc-pV6Z基组，对ClO自由基和O2分子进行了计算，并拟合了其M-S势能函数．采用密度泛函方法（B3LYP）在6-311G（3dr）基组下对ClO2自由基的结构进行了优化计算，得到：ClO2自由基的稳态结构为C2v构型，电子态为2B1、平衡核间距RCIO=0．14785nm、键角∠OClO=117．3107°、离解能Dc=2．7552eV、基态振动频率v1（a1）=451．3423am^-1，v2（a1）=970．8289cm^-1，v3（b2）=1123．5023cm^-1．采用多体项展式理论推导了ClO2自由基的基态解析势能函数，其等值势能图准确再现了该分子的结构特征及其势阱深度与位置．分析讨论势能面的静态特征时得到：在ClO＋O→ClO2反应中存在两个对称的鞍点，分别位于（0．24812m，0．152nm）和（0．152nm，0．248nm）处，活化能为5．614kcal／mol

英文摘要：

Density functional theory method（B3LYP） is used to optimize the possible ground-state structures of CIO radical and O2 molecule. The analytical potential energy functions of the two molecules are fitted using Murrell-sorbie function and least square fitting method. B3LYP method is used to optimized the ground state structure of ClO2 radical also. The result shows that the ground state of ClO2 radical is of C2v symmetry and of 2B1 state , the parameters of structure and the harmonic frequencies are of RCIO=0.14785nm、∠OClO=117.3107°、Dc=2.7552eV、v1（a1）=451.3423am^-1,v2（a1）=970.8289cm^-1,v3（b2）=1123.5023cm^-1. The potential energy function of ClO2 radical is derived from the many-body expansion theory. The potential energy function describe correctly the configuration and the dissociation energy. Molecular reaction kinetic of ClO＋O on the potential energy functions is discussed briefly.