PuNO分子结构与势能函数  

Structure and potential energy function of Pu NO molecules

作　　者：郝丹辉[1] 孔凡杰[2] 蒋刚[3] 

机构地区：[1]西安建筑科技大学华清学院,西安710043 [2]盐城工学院数理学院,盐城224051 [3]四川大学原子与分子物理研究所,成都610065

出　　处：《物理学报》2015年第15期62-68,共7页Acta Physica Sinica

摘　　要：本文运用密度泛函理论的B3LYP方法,对钚原子应用LANL2DZ收缩价基函数,氮、氧原子采用AUG-cc-p VTZ基函数,分别对Pu N,Pu O,NO和Pu NO体系进行了结构优化,得到Pu NO分子最稳构型为C∞v(Pu-N-O),电子态为6Σ(基态),平衡核间距RON=0.12257 nm,RNPu=0.22951 nm,离解能D e=8.10537 e V.同时优化得到Pu NO分子存在两种亚稳态平衡构型分别为C∞v(Pu-O-N),6Σ(电子态)和Cs(O-Pu-N),A′′(电子态),以及分子体系相应的力学常数等.拟合出Pu N,Pu O和NO分子的Murrell-Sorbie势能函数,并使用多体项展式理论得到了Pu NO分子的分析势能函数,其等值势能图准确再现了Pu NO分子最稳态构型及两个亚稳态构型的离解能和结构特性,由此讨论了该分子体系的势能面静态特征.Density functional（B3LPY） method has been utilized to optimize the possible structures of PuN, PuO, NO and PuNO molecules using the contracted valence basis set（LANL2 DZ） for Pu atom, and the AUG-cc-p VTZ basis set for N and O atoms. It is shown that the ground state of the PuNO molecules has C v（Pu-N-O） symmetry and the ground electronic state is ^6Σ-. The equilibrium nuclear distances for Pu-N and N-O bonds in the PuNO molecules are RPuN = 0.22951 nm and RNO = 0.12257 nm, and the dissociation energy is De= 8.10537 e V. Furthermore, the other two metastable states of the PuNO molecules are also obtained, and the electronic states of the two configurations are ^6Σ- and A″ with C v（Pu-O-N） and Cs（O-Pu-N） symmetry, respectively. Then the Murrell-Sorbie potential energy functions of the PuN, PuO and NO molecules have been simulated and the analytical potential energy function of the PuNO molecules has been derived using the many-body expansion theory. The contours of the potential energy functions reproduce exactly the most stable equilibrium structures, the two metastable state structures as well as the dissociation energy of the PuNO molecules. The molecular static reaction pathway, based on the potential energy function, is also discussed.

关 键 词：PU NO 分子结构 势能函数 

分 类 号：O561[理学—原子与分子物理]