Chemical dynamics simulations have been performed to study the NH₂ + NO₂ reaction on singlet potential energy surface at 298 K. To obtain more accurate potential energy surface, seven methods including MP2, B3LYP, OPBE, BhandH, HCTH407, M06 and M06–2X combined with aug-cc-pVDZ basis set were employed to calculate the properties of stationary points and the results are compared with the higher level CCSD(T) benchmark and the available theoretical and experimental values. The reaction reactivity, product branching ratio, and detailed microscopic reaction mechanisms are uncovered by direct dynamics simulations at the chosen B3LYP/aug-cc-pVDZ level of theory. The branching ratio between product P1 (N₂O + H₂O) : P2 (H₂NO + NO) determined in current study is 0.22 : 0.78, which is in consistent with experimental observations. The study reveals a preference of P2 channel over P1 at 298 K, although the latter channel is more exothermic. This result indicates the dynamical factors govern the competition of two product channels. Three atomic mechanisms were determined and discussed in detail, in which the indirect reaction dominates. Interestingly, these indirect reactions follow the intrinsic reaction coordinate of the potential energy surface.

已经进行了化学动力学模拟，以研究298 K时单线态势能表面上的NH ₂  + NO ₂反应。为了获得更准确的势能表面，共有7种方法，包括MP2，B3LYP，OPBE，BhandH，HCTH407，M06和M06-2X结合aug-cc-pVDZ基集计算固定点的特性，并将结果与​​更高级别的CCSD（T）基准以及可用的理论和实验值进行比较。在所选的B3LYP / aug-cc-pVDZ理论水平上，通过直接动力学模拟未发现反应活性，产物支化比和详细的微观反应机理。产物P1（N ₂ O + H ₂ O）：P2（H ₂）之间的支化比目前研究确定的NO + NO）为0.22：0.78，与实验观察结果一致。这项研究揭示了在298 K时P2通道比P1通道更偏爱，尽管后者通道更容易放热。该结果表明动力学因素决定着两个产品渠道的竞争。确定并详细讨论了三种原子机理，其中间接反应占主导。有趣的是，这些间接反应遵循势能表面的固有反应坐标。