【摘要】 用从头算的MP2（FULL）／6－31G（d）方法、反应途径哈密顿理论以及变分过渡态理论，计算了NH（X3∑－）＋NH3→2NH2的反应途径、沿反应途径的动态学性质和正则变分过渡态理论的速率常数．在此基础上计算了振动选态反应的速率常数．结果表明：此反应存在较小的返回效应，变分的效果不明显;较低温度下考虑隧道效应更重要，且小曲率近似的校正是有效的;振动选态激发对反应速率常数有较大增加．计算所得速率常数与现有实验结果相吻合。更多还原

【Abstract】 The dynamic properties along the reaction path and CVT reaction rate constants of NH(X3∑-) +NH3→2NH2 have been investigated by using ah initio MP2 (FULL) /6 - 31G (d)calculation, reaction path Hamiltonian theory and variational transition state theory. On this basis, the vibrational state-selected reaction rates are calculated. The results show that there is little recrossing effect and the effects of CVT method are negligible; it is more important to include the tunneling effect in lower temperature range. The small curvature approximation method proves to be efficient, the rate enhancement is notable because of viblational excitation. The calculated rate constants agree perfectly with the available experimental data.更多还原