二氧化钚分子的多体展式势能函数

从导出基态PuO2分子的电子状态X5Σ g正确地判断其离解极限出发,采用MP2方法,应用相对论有效原子实模型(RECP)优化出PuO2(X5Σ g)分子稳定构型为线性OPuO(D∞h),其平衡核间距Re=0.18004nm.同时也计算出振动频率,并优化出存在亚稳态的Pu-O-O(C∞v)构型.使用多体项展式理论方法,导出了基态PuO2分子的分析势能函数.该势能表面准确地再现了O-Pu-O(D∞h)平衡结构和亚稳态的Pu-O-O(C∞v)构型.然后根据势能函数等值图讨论了O(3Pg) PuO反应的势能面静态特征.

Many-body Expanded Analytical Potential Energy Function for the Ground State of PuO2 Molecule

The ground electronic state X 5Σ + g and the reasonable dissociation limits of the PuO2 molecule are derived based on the Atomic and Molecular Reactive Statics. In the MP2 (The HF calculation followed by a second-order Moller-Plesset correlation) level, using the RECP(relativistic effective core potential) for Pu atom and 6 311G* basis for O atom , the present work has optimized the equilibrium geometry for the linear O-Pu-O( D ∞h ), ground state X 5Σg + of PuO2, whose equilibrium nuclear distance and dissociation energy are 0.180 04nm and 12.551 eV respectively. And the metastable structure Pu-O-O( C ∞v )is found for the first time, which is 6.79 eV higher than the stable structure. The analytical potential energy function for the ground state X 5Σg + of PuO 2 has also been derived using many body expansion method, the potential energy function is successfully used for describing the equilibrium geometry of PuO 2 and PuOO, which is adequately accurate in the whole region for the dynamical research.