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化学学报
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化学学报 ›› 2005, Vol. 63 ›› Issue (4): 263-268. 上一篇    下一篇

研究论文

OH自由基的高精度量子化学研究

马海涛1,2, 边文生*,2, 郑世钧1, 孟令鹏*,1   

  1. (1河北师范大学化学学院计算量化研究所　石家庄 050091)
    (2中国科学院化学研究所　分子反应动力学国家重点实验室　北京 100080)
  • 投稿日期:2004-09-20 修回日期:2004-10-29 发布日期:2010-12-10
  • 通讯作者: 边文生, 孟令鹏

Highly Accurate Quantum Chemical Study of the OH Radical

MA Hai-Tao1, 2, BIAN Wen-Sheng*, 2,ZHENG Shi-Jun1, MENG Ling-Peng*,1   

  1. (1 Institute of Computational Quantum Chemistry, Hebei Normal University, Shijiazhuang 050091)
  • Received:2004-09-20 Revised:2004-10-29 Published:2010-12-10
  • Contact: BIAN Wen-Sheng, MENG Ling-Peng

PDF

1338

被引次数

30 | 7

采用内收缩MRCI方法(Internally Contracted Multiconfiguration-Reference Configuration Interaction)研究了OH自由基, 计算得到其基态稳定构型的键长是0.09708 nm, 对应的实验值是0.096966 nm, 第一激发态的键长是0.10137 nm,实验值是0.10121 nm. 同时得到势能曲线PECs (Potential Energy Curve), 再分别由Murrell-Sorbie势能函数拟合计算和POLFIT程序计算得到OH自由基在基态X2Π和第一激发态A2Σ+时的光谱数据：平衡振动频率ωe, 非谐性常数ωeχe以及高阶修正ωeYe, 平衡转动常数Be, 振转耦合系数αe, 解离能D0和垂直跃迁能量ν00. 这些理论计算结果与最新的实验值非常吻合, 精确度比前人也有很大提高. 其中我们计算得到基态OH(X2Π)的解离能D0＝35568.86 cm－1, 第一激发态OH (A2Σ+)的解离能D0＝18953.93 cm－1, 从第一激发态A2Σ+ (ν＝0)到基态X2Π (v＝0)的垂直跃迁能ν00＝32496.42 cm－1.

关键词: OH自由基, IC-MRCI方法, 光谱参数, 解离能De

Two potential energy curves for the ground electronic state X2Π and the first excited electronic state A2Σ+ of OH radical have been calculated using the internally contracted multiconfiguration-reference configuration interaction (IC-MRCI) method including Davidson correction. And they were fitted to analytical potential energy functions using the Murrell-Sorbie potential function to deduce the spectroscopic parameters: equilibrium bond length Re, rotation coupling constant ωe, anharmonic constant ωeχe, equilibrium rotation constant Be and vibration-rotation coupling constant αe. These constants and higher-order anharmonic constant ωeYe were also calculated by POLFIT. Most of the values obtained are in excellent agreement with experimental results. The calculated dissociation energy D0 for OH(X2Π) is 35568.86 cm－1, which is in excellent agreement with the recent experimental value (35565±30) cm－1. The calculated dissociation energy D0 for OH(A2Σ+) is 18953.93 cm－1. The calculated vertically excited energy from the ground state X2Π (v＝0) to the first excited state A2Σ+ (ν＝0) is 32496.42 cm－1.

Key words: OH radical, IC-MRCI, spectroscopic parameter, dissociation energy