Influence of Singlet\nOxygen in H + O<sub>2</sub> Collision\nReaction

The collision reaction of H + O<sub>2</sub> = OH + O\nis a pivotal\nstep in combustion. To investigate the influence of singlet oxygen\non this reaction, we computed potential energy surfaces (PESs) for\nall six lowest states using high-level <i>ab initio</i> methods\nand coupled them with embedded atom neural network (EANN) fitting.\nBy integrating quasi-classical trajectory (QCT) with trajectory surface\nhopping (TSH) based on the fitted PESs, we simulated the dynamics\nof both ground- and excited-states to derive the reaction rate constants\nfor the forward and reverse processes. The results reveal that the\nforward reaction facilitates radical generation, promoting combustion\nreactions. Furthermore, calculations of reverse reaction rate constants\nindicate that all electronic states ultimately yield ground-state\noxygen, leading to radical deactivation and exerting an inhibitory\neffect on combustion processes.