Subnano surface-supported catalytic clusters can be generally characterized by many low-energy isomers accessible at elevated temperatures of catalysis. The most stable isomer may not be the most catalytically active. Additionally, isomers may interconvert across barriers, i.e., exhibit fluxionality, during catalysis. To study the big picture of the cluster fluxional behavior, we model such a process as isomerization graph using bipartite matching algorithm, harmonic transition state theory, and paralleled nudged elastic band method. All the minimal energy paths form a minimum spanning tree (MST) of the original graph. Detailed inspection shows that, at temperatures typical for catalysis, the cluster geometry changes frequently within several regions in the MST, while transition across regions is less likely. As a further confirmation, the structural similarity analysis was additionally performed based on molecular dynamics trajectories. This local fluxionality picture provides a new perspective on understanding finite-temperate catalytic processes.

中文翻译：

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表面沉积簇状催化剂的局部流动性：Al ₂ O ₃上Pt ₇的情况

亚纳米表面负载的催化簇通常可以通过在催化温度升高时可得到的许多低能异构体来表征。最稳定的异构体可能不是最具催化活性的。另外，异构体可以在催化过程中跨势垒相互转化，即表现出流动性。为了研究团簇通量行为的全貌，我们使用二分匹配算法，谐波过渡态理论和平行微带弹性带方法对异构化图等过程进行建模。所有最小能量路径均形成原始图的最小生成树（MST）。详细的检查表明，在典型的催化温度下，团簇的几何形状在MST的多个区域内频繁变化，而跨区域过渡的可能性较小。为了进一步确认，另外，基于分子动力学轨迹进行结构相似性分析。这张局部通量图为理解有限温度催化过程提供了新的视角。