B2C(1A1)和BC2(2A′)的结构与解析势能函数

采用单双取代的二次组态相互作用方法，分别选用6-311++G(d,p)和6-311G(df,pd)基组，对B₂C和BC₂分子的结构进行了优化，得到这两个分子的基态结构为C_2v和C_s，基态电子状态为¹A₁和²A′，同时还得到了它们的平衡几何结构、离解能、谐振频率和力常数. 关键词： 碳化硼 Murrell-Sorbie函数 谐振频率 势能函数

The structure and potential energy function of B2C(1A1)and BC2(2A')

Quadratic configuration interaction method including single and duble substitutions has been used to optimize the possible ground-state structures of B₂C and BC₂ molecules with the 6-311++G(d, f) and 6-311G(df, pd) basis set. The results show that the ground state of B₂C molecule is of C_2v symmetry and of ¹A₁ state, the ground state of BC₂ molecule is of C_s symmetry and of ²A′ state. And the equilibrium geometry, dissociation energy, harmonic frequency and force constant have been calculated. The potential energy functions of B₂C and BC₂ have been derived from the many-body expansion theory. The potential energy functions describe correctly the configurations and the dissociation energies of the two ground-state molecules. Molecular reaction kinetics of B+BC→B₂C and B+CC→BC₂ based on the potential energy functions is discussed briefly.