Many-body expanded analytical potential energy function for the ground state of PuO2 molecule

作者：Gao, T^*; Wang, HY; Huang, Z; Zhu, ZH; Sun, Y; Wang, XL; Fu, YB

来源：Acta Physico - Chimica Sinica, 1999, 15(12): 1082-1087.

DOI：10.3866/PKU.WHXB19991206

• PuO2
• ground states
• relativistic effective-core potential (RECP)
• Potential energy function
• many-body expansion

The ground electronic state X(5)Sigma(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-infinity (h)), ground state X(5)Sigma(g)(+) of PuO2, whose equilibrium nuclear distance and dissociation energy are 0.180 04 nm and 12.551 eV respectively, And the metastable structure Pu - O - O(C-infinity nu) 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(5)Sigma(g)(+) of PuO2 has also been derived using many-body expansion method, the potential energy function is successfully used for describing the equilibrium geometry of PuO2 and PuOO, which is-adequately accurate in the whole region for the dynamical research.

• 出版日期1999-12
• 单位中国工程物理研究院; 四川大学