论文标题
索引-2马鞍的经典和量子动力学表现：协调与顺序反应机制
Classical and quantum dynamical manifestations of index-2 saddles: concerted versus sequential reaction mechanisms
论文作者
论文摘要
通常认为在多维势能表面上存在较高的指数马鞍在化学反应动力学中没有意义。这种观点需要仔细的重新考虑，这要归功于近年来出现的优雅实验和新颖的理论方法。在这项工作中，我们对模型两度自由汉密尔顿人进行了详细的经典和量子动力学研究，该研究捕获了有关协同反应机制或逐步反应机制的辩论的本质。我们表明，从一致的机制到逐步的机制的超快转移本质上是经典的动力学效果。此外，由于经典相位空间是常规和混乱动力学的混合物，因此即使在高于Index-2 Saddle的能量上，也有可能具有丰富的动力学行为，包括默雷尔·塞勒类型的机制。我们使用相位空间中经典不变的歧管的明确结构合理化了动态结果。
The presence of higher index saddles on a multidimensional potential energy surface is usually assumed to be of little significance in chemical reaction dynamics. Such a viewpoint requires careful reconsideration, thanks to elegant experiments and novel theoretical approaches that have come about in recent years. In this work, we perform a detailed classical and quantum dynamical study of a model two degree of freedom Hamiltonian, which captures the essence of the debate regarding the dominance of a concerted or a stepwise reaction mechanism. We show that the ultrafast shift of the mechanism from a concerted to a stepwise one is essentially a classical dynamical effect. In addition, due to the classical phase space being a mixture of regular and chaotic dynamics, it is possible to have a rich variety of dynamical behaviour, including a Murrell-Laidler type of mechanism, even at energies sufficiently above that of the index-2 saddle. We rationalize the dynamical results using an explicit construction of the classical invariant manifolds in the phase space.
