The kinetics of the reactions H₂NO + O₂(³${\Sigma }_{\mathrm{g}}^{-}$) → HNO(${\tilde{\mathrm{X}}}^1{\mathrm{A}}^{\prime }$) + HO₂ and NH₂ + HO₂ → NH₃ + O₂(³${\Sigma }_{\mathrm{g}}^{-}$), which are, respectively, very sensitive chain-propagation and chain-termination reactions in ammonia kinetic models, have been revisited by means of high-level electronic structure and variational transition state theory calculations with the goal of improving former predictions and the performance of ammonia kinetic models. In addition, the rate constants of the reactions H₂NO + O₂(³${\Sigma }_{\mathrm{g}}^{-}$) → HNO(${\tilde{a}}^3{\mathrm{A}}^{″}$) + HO₂, NH₂ + HO₂ → H₂NO + OH, and NH₂ + HO₂ → NH₃ + O₂(¹${\Delta }_{\mathrm{g}}$), which take place on excited-state potential energy surfaces and/or yield the electronically excited species HNO(${\tilde{a}}^3{\mathrm{A}}^{″}$) and O₂(¹${\Delta }_{\mathrm{g}}$), have been also calculated for the first time in order to assess their importance in ammonia oxidation. We observed that spin contamination and multi-reference character are pronounced in many of the investigated reactions, and these features were handled by performing post-CCSD(T) electronic structure calculations with the W3X-L composite method as well as restricted open shell coupled cluster calculations. Branching ratios were also analyzed, and indicate that the contribution of the electronically excited species HNO(${\tilde{a}}^3{\mathrm{A}}^{″}$) and O₂(¹${\Delta }_{\mathrm{g}}$) are of little importance even at very high temperatures; however, we do not preclude an effect of those species at certain conditions that contribute to their yield. The calculated rate constants were implemented in two recent kinetic models to perform jet stirred reactor, rapid compression machine, and flow reactor simulations, concluding that the model predictions are very sensitive to the reactions H₂NO + O₂(³${\Sigma }_{\mathrm{g}}^{-}$) → HNO(${\tilde{\mathrm{X}}}^1{\mathrm{A}}^{\prime }$) + HO₂ and NH₂ + HO₂ → NH₃ + O₂(³${\Sigma }_{\mathrm{g}}^{-}$) .

反应动力学 H ₂ NO + O ₂ ( ³${\Sigma }_{\mathrm{G}}^{-}$) → 硝酸(${\stackrel{～}{\mathrm{X}}}^1{\mathrm{一种}}^{\prime }$) + HO ₂和 NH ₂  + HO ₂  → NH ₃  + O ₂ ( ³${\Sigma }_{\mathrm{G}}^{-}$)，它们分别是氨动力学模型中非常敏感的链传播和链终止反应，已通过高级电子结构和变分过渡态理论计算重新审视，目的是提高以前的预测和性能氨动力学模型。此外，反应的速率常数 H ₂ NO + O ₂ ( ³${\Sigma }_{\mathrm{G}}^{-}$) → 硝酸(${\stackrel{～}{\mathrm{一种}}}^3{\mathrm{一种}}^{”}$) + HO ₂、NH ₂  + HO ₂  → H ₂ NO + OH 和 NH ₂  + HO ₂  → NH ₃  + O ₂ ( ¹${\Delta }_{\mathrm{G}}$)，发生在激发态势能表面和/或产生电子激发的物质 HNO(${\stackrel{～}{\mathrm{一种}}}^3{\mathrm{一种}}^{”}$) 和 O ₂ ( ¹${\Delta }_{\mathrm{G}}$)，也首次计算以评估它们在氨氧化中的重要性。我们观察到自旋污染和多参考特征在许多研究的反应中都很明显，这些特征是通过使用 W3X-L 复合方法以及受限开壳耦合簇进行后 CCSD(T) 电子结构计算来处理的计算。还分析了支化率，并表明电子激发物质 HNO（${\stackrel{～}{\mathrm{一种}}}^3{\mathrm{一种}}^{”}$) 和 O ₂ ( ¹${\Delta }_{\mathrm{G}}$) 即使在非常高的温度下也不重要；然而，我们不排除这些物种在有助于其产量的某些条件下的影响。计算的速率常数在两个最近的动力学模型中实现，以执行喷射搅拌反应器、快速压缩机和流动反应器模拟，得出的结论是模型预测对反应 H ₂ NO + O ₂ ( ³${\Sigma }_{\mathrm{G}}^{-}$) → 硝酸(${\stackrel{～}{\mathrm{X}}}^1{\mathrm{一种}}^{\prime }$) + HO ₂和 NH ₂  + HO ₂  → NH ₃  + O ₂ ( ³${\Sigma }_{\mathrm{G}}^{-}$)。