物理化学学报 >> 1999, Vol. 15 >> Issue (12): 1082-1087.doi: 10.3866/PKU.WHXB19991206

研究论文 上一篇    下一篇

二氧化钚分子的多体展式势能函数

高涛, 王红艳, 黄整, 朱正和, 孙颖, 汪小琳, 傅依备   

  1. 四川大学原子分子工程所，成都 610065|中国工程物理研究院，成都 610003
  • 收稿日期:1999-03-17 修回日期:1999-05-24 发布日期:1999-12-15
  • 通讯作者: 高涛

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

Gao Tao, Wang Hong-Yan, Huang Zheng, Zhu Zheng-He, Sun Ying, Wang Xiao-Lin, Fu Yi-Bei   

  1. Institute of Atomic and Molecular Physics,Sichuan University,Chengdu 610065|China Academy of Engineering Physics,Mianyang 610003
  • Received:1999-03-17 Revised:1999-05-24 Published:1999-12-15
  • Contact: Gao Tao

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摘要：

从导出基态PuO2分子的电子状态X5Σg+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(X5Σg +)分子稳定构型为线性O-Pu-O(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.

关键词: PuO2, 基态, 相对论有效原子实势(RECP), 多体展式势能函数

Abstract:

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. 

Key words: PuO2, Ground sttes, Relativistic effective core potential(RECP), Potential energy function, Many-body expansion