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化学学报
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化学学报 ›› 2005, Vol. 63 ›› Issue (8): 764-768. 上一篇    下一篇

研究简报

PdYH分子的结构与势能函数

倪羽ac，蒋刚1*，朱正和1，孙颖2   

  1. (1 四川大学原子分子物理研究所 成都 610065)
    (2中国工程物理研究院 绵阳 621900)
    (3 四川师范大学化学学院 成都 610066)
  • 投稿日期:2004-07-16 修回日期:2004-12-21 发布日期:2010-12-10
  • 通讯作者: 蒋刚

Structures and Potential Energy Functions of PdYH Molecule

NI Yu1,3, JIANG Gang1*, ZHU Zheng-He1, SUN Ying2   

  1. (1 Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065)
    (2 China Academy of Engineering Physics, Mianyang 621900)
    (3 Chemistry Department, Sichuan Normal University, Chengdu 610066)
  • Received:2004-07-16 Revised:2004-12-21 Published:2010-12-10
  • Contact: JIANG Gang

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被引次数

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用密度泛函理论的B3LYP方法, 对钯和钇原子采用SDD收缩价基函数, 氢原子采用6-311＋＋G**全电子基函数, 对PdY和PdYH体系的结构进行优化. 计算表明: PdY分子的几何构型为C∞v, 其基态为X2Σ＋态, 键长R＝0.24168 nm, 离解能为De＝2.8261 eV, 谐振频率ωe＝254.0656 cm－1, 并拟合得到Murrell-Sorbie势能函数; PdYH分子最稳态为Cs构型, 电子组态为1A', 平衡核间距RPdY＝0.24281 nm, RYH＝0.19824 nm, 键角∠PdYH＝116.7157°, 离解能De＝5.6146 eV, 基态简正振动频率: 对称伸缩振动频率ν1 (a')＝348.2909 cm－1, 弯曲振动频率ν2 (a')＝243.3382 cm－1, 反对称伸缩振动频率ν3 (a')＝1442.2695 cm－1. 由微观过程的可逆性原理分析了分子的可能离解极限. 并用多体项展式理论方法分别导出基态PdY和PdYH分子的势能函数, 其等值势能面图准确地再现了PdY和PdYH分子的结构特征和离解能, 由此讨论了Pd＋Y＋H分子反应的势能面静态特征.

关键词: PdY, PdYH, 相对论有效原子实势, 多体展式势能函数

Density functional method (B3LYP) has been used to optimize the possible structures of PdY and PdYH molecules by contracted valence basis set (SDD) for Pd and Y atoms and the 6-311＋＋G** basis set for H atom. The results show that the ground states of PdY and PdYH molecules are X2Σ＋ and X1A' states, respectively. The equilibrium geometry R＝0.24168 nm, dissociation energy De＝2.8261 eV, and spectral constants ωe＝254.0656 and ωexe＝0.60391 cm－1 of PdY (C∞v) molecule have been obtained, respectively. For PdYH (Cs) molecule, the equilibrium geometry, dissociation energy and harmonic frequency were calculated, and the results show that RPdY＝0.24281 nm, RYH＝0.19824 nm, ∠PdYH＝116.7157° and De＝5.6146 eV, and ν1 (a')＝348.2909 cm－1, ν2 (a')＝243.3382 cm－1, ν3 (a') ＝1442.2695 cm－1, respectively. Analytical potential energy function for the PdYH has been derived for the first time using many-body expansion method, which was successfully used for describing the equilibrium geometry of PdYH. Molecular reaction kinetics of Pd(1Sg)＋Y(2Dg)＋H(2Sg) based on this potential energy function is being studied under way.

Key words: PdY, PdYH, relativistic effective core potential, many-body expansion potential energy function