PuC和PuC2的分子结构与势能函数

采用密度泛函B3LYP方法和相对论有效原子实理论模型优化出PuC和PuC2分子稳定构型,其电子状态分别为X5Σ－和X5A2.PuC2分子为C2v构型,其∠CPuC=147.67°,平衡核间距Re=0.22819 nm, 离解能De=5.543 eV, 并计算出谐振动频率:ν1=61.736 cm－1、ν2=229.894 cm－1、ν3=305.582 cm－1.在此基础上,运用多体项展式理论方法,导出了基态PuC2分子的分析势能函数,该势能面准确地再现了PuC2分子的稳定结构,并根据势能面等值图讨论了PuC＋C反应和Pu＋C2反应的势能面静态特征.

Molecular Structures and Potential Function for PuC and PuC2 Molecules

Density function (B3LYP) method with relativistic effective core potential (RECP) have been used to optimize the structures for the ground states (X5Σ－,X5A2) of PuC and PuC2 molecules. For PuC2（C2v） molecule, the equilibrium geometry, dissociation energy and harmonic frequency are calculated, the results show that RPuC=0.22819 nm,∠CPuC=147.67°and De=5.543 eV, and ν1,ν2 and ν3 are 61.736 cm－1,229.89 cm－1,305.58 cm－1, respectively. Analytical potential energy function for the PuC2 has been derived using many-body expansion method which is successfully used for describing the equilibrium geometry of PuC2.Molecular reaction kinetics of C＋PuC and Pu＋C2 based on this potential energy function is under way.