论文标题
稳定的混乱和单分子解离反应中统计的发作延迟
Stable chaos and delayed onset of statisticality in unimolecular dissociation reactions
论文作者
论文摘要
统计模型通过绕过需要详细且通常很困难的动态考虑的需求来计算反应速率的强大而有用的近似类别。这种方法总是会引起有关系统中分子内振动能流量程度的特定假设。但是，向统计方案转变为分子参数的函数的性质远非完全理解。在这里，我们使用非线性动力学的工具来研究模型单分子反应中的统计性，通过明确审查高维经典相空间。我们在相空间中确定涉及两个或多个独立的非谐和共振的相交的相位空间中的通用特征，并表明相关但混乱的分子内动力学在此类交界处附近导致非统计性。有趣的是，类似于太阳系中小行星的稳定性，由于稳定混乱的现象，分子可以保护几次picseconds的连接处的离解。
Statistical models provide a powerful and useful class of approximations for calculating reaction rates by bypassing the need for detailed, and often difficult, dynamical considerations. Such approaches invariably invoke specific assumptions about the extent of intramolecular vibrational energy flow in the system. However, the nature of the transition to the statistical regime as a function of the molecular parameters is far from being completely understood. Here, we use tools from nonlinear dynamics to study the transition to statisticality in a model unimolecular reaction by explicitly visulaizing the high dimensional classical phase space. We identify generic features in the phase space involving the intersection of two or more independent anharmonic resonances and show that the presence of correlated, but chaotic, intramolecular dynamics near such junctions leads to nonstatisticality. Interestingly, akin to the stability of asteroids in the Solar System, molecules can stay protected from dissociation at the junctions for several picoseconds due to the phenomenon of stable chaos.
