计算物理 ›› 2019, Vol. 36 ›› Issue (1): 106-112.DOI: 10.19596/j.cnki.1001-246x.7797

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POX(X=1,2)的光谱常数与从头算势能曲线

韩晓琴1, 肖夏杰2   

  1. 1. 商丘师范学院电子电气工程学院, 河南 商丘 476000;
    2. 河南质量工程职业学院, 河南 平顶山 467000
  • 收稿日期:2017-11-08 修回日期:2018-01-10 出版日期:2019-01-25 发布日期:2019-01-25
  • 作者简介:韩晓琴(1975-),女,硕士,副教授,主要从事原子与分子结构与动力学研究,E-mail:hanxiaoqin88@163.com
  • 基金资助:
    国家自然科学基金(11074160)及河南省科技攻关计划(102102210037)资助项目

Spectral Constants and ab Initio Potential Energy Curves of POX(X=1,2)

HAN Xiaoqin1, XIAO Xiajie2   

  1. 1. Department of Physics, Shangqiu Normal College, Shangqiu 476000, Henan, China;
    2. Henan Quality Polytechnic, Pingdingshan 467000, Henan, China
  • Received:2017-11-08 Revised:2018-01-10 Online:2019-01-25 Published:2019-01-25

摘要: 采用从头算的多种方法对PO、PO2自由基的基态结构进行优化计算,结果表明:使用密度泛函(DFT)方法计算的结果最接近实验值.对PO双原子分子优选6-311G(3df)基组进行计算、扫描并拟合.对PO2三原子分子优选出6-311+G(3df)方法计算结构参数、谐振频率、离解能及力常数,借助多体项展式理论导出PO2自由基的势能函数并绘制等值势能图.发现:PO2自由基的对称伸缩振动和旋转势能图中,在O+PO→OPO反应通道上都有鞍点出现,O原子需要越过0.55 eV的能量才能生成稳定的PO2自由基.要形成PO2自由基只能通过两等价的通道越过势垒才能形成.

关键词: PO, PO2, 光谱常数, 从头算, 势能曲线

Abstract: Many methods are used to optimize possible ground state structures of PO、PO2 with multi-basis set. It was found that DFT method is the most suitable for calculation of PO,PO2. For PO free radical, M-S potential energy functional constants are calculated with 6-311G(3df). For PO2 free radical, equilibrium structure, harmonic frequency, dissociation energy and force constant are calculated with 6-311+G(3df). Potential energy functions of PO2 are derived from many-body expansion theory. It was pointed out that there is a saddle point in reaction kinetics O+PO→OPO, and a stable PO2 molecule could be formed as O atom with energy surpassing 0.55 eV. A stable PO2 molecule could be formed through two equivalent channels over barrier.

Key words: PO, PO2, spectral constant, ab initio, potential energy curve

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