PuC和PuC_2的分子结构与势能函数

Molecular Structures and Potential Function for PuC and PuC_2 Molecules

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=0.22819nm、离解能De=5.543eV,并计算出谐振动频率:ν1=61.736cm-1、ν2=229.894cm-1、ν3=305.582cm-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.

Density function (B3LYP) method with relativistic effective core potential (RECP) have been used to optimize the structures for the ground states (X(5)Sigma(-), X(5)A(2)) of PuC and PuC2 molecules. For PuC2(C-2nu) molecule, the equilibrium geometry, dissociation energy and harmonic frequency are calculated, the results show that R-PuC = 0.22819 nm, angle CPuC = 147.67degrees and D-e = 5.543 eV, and nu(1), nu(2) and nu(3) 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 + C-2 based on this potential energy function is under way.