PuN基态分子势能函数与热力学函数的理论计算

在Pu的相对论有效原子实势近似和N原子6-311G*全电子基函数下,用密度泛函B3LYP方法计算得到PuN分子基态X6∑+的结构与势能函数、力常数与光谱数据.同时计算得到PuN(g)分子在298 K时的标准生成热力学函数△fH0、△S0和△fG0,分别为-487.239 kJ/mol、95.345 J/mol K和-515.6661 kJ/mol.

The Theoretical Calculation of Potential Energy Functions and Thermodynamic Functions for the Ground State of PuN

The potential energy function, force constant and spectroscopic data for the ground state X6Σ+ of PuN have been derived by the Gaussian 98 program with the B3LYP method, based on the approximation of relativistic effective core potential for Pu atom and all-electron 6-311G* basis set for N atom. The separated atomic group method is used to derive the possible electronic states for PuN. The ground states for Pu and N are4Su, respectively, which are the components of irreducible representation of the SU(n) group. PuN belongs to the C∞v group. The irreducible representations of the SU(n) group can be resolved into those of the C∞v group. That is, the possible electronic states of PuN are given. Pu(7Fg) and N(4Su) are resolved into the direct sum of C∞v. Their direct product and its reduction are the possible electronic states of PuN. Dissociation limit is derived by atomic and molecular reaction statics. The potential energy function of the ground state for PuN molecule is derived byab initiowith the B3LYP method, based on the approximation of relativistic effective core potential for Pu atom and all-electron 6-311G* basis set for N atom and fitting the Murrell-Sorbie (M-S ) function. In addition, the thermodynamic functionΔfH0、ΔS0andΔfG0of PuN(g) in the standard state are also calculated, which are -487.239 kJ/mol, 95.345 J/mol K and -515.6661 kJ/mol, respectively.