Dynamics of Pressure-Dependent Atmospheric Reactions

这项研究涉及使用计算方法来研究缔合反应的一个潜在的重要途径，即两个物种在解离到最终产品之前结合形成一个亚稳定的中间物种的化学反应。潜在的途径包括将多余的能量转移到浴气的途径。标准的能量转移机制(ETM)已经被成功地用来解释一些对大气重要的缔合反应。另一种过程是伴侣机制(CM)，它可以解释为什么一些缔合反应具有多个通道或对非反应物种(例如水蒸气)的浓度有异常的依赖。将制定一个详细的框架来处理缔合反应的CM组分，并将研究使用振动激发物种的猝灭速率作为使用高压极限缔合速率系数的替代方案的实用性。最后，将开发一个计算机程序，其中包括这项研究的主要结果，并将免费分发给所有感兴趣的各方。这项研究的结果虽然与大气化学有关，但也将有助于研究燃烧、行星大气和其他化学反应系统的研究人员。

This study involves the use of computational methods to investigate a potentially important pathway for association reactions, being those chemical reactions in which two species combine to form a metastable intermediate species before dissociating to the final products. The potential pathways involve the ways in which excess energy is transferred to the bath gas. The standard Energy Transfer Mechanism (ETM) has been employed successfully to explain a number of atmospherically important association reactions. The alternative process is the Chaperone Mechanism (CM) that could explain why some association reactions have multiple channels or unusual dependence on concentrations of non-reacting species (for example, water vapor). A detailed framework for dealing with the CM component of association reactions will be developed, and an investigation of the utility of using the rate of quenching of vibrationally excited species as an alternative to using the high pressure limiting association rate coefficient will also be undertaken. Finally, a computer program will be developed that incorporates the key findings of this study and will be freely distributed to all interested parties. The results of this research, while relevant to atmospheric chemistry, will also benefit researchers studying combustion, planetary atmospheres, and other chemically reacting systems.