Exploring Structural Diversity and Fluxionality of Ptn (n=10-13) Clusters from First-Principles

Subnanometer transition-metal clusters have been, shown to possess catalytic activity that is size-dependent. It has been suggested that the fluxionality of these small clusters may be closely related to their catalytic activity. Here we use basin-hopping global optimization with density functional theory (DFT) to study the energy landscape of Pt-n (n = 10-13) clusters. We analyze a large set of local minima obtained from the DFT-based global optimization. We find that Pt-10 is unique with respect to the other studied sizes in its structural landscape, which shows a single, distinct structural motif corresponding to a tetrahedral global minimum. In contrast, Pt11-13 all display characteristics of high fluxionality with the presence of multiple significantly differing structural features in the low-energy region, as characterized by coordination number, interatomic distances, and shape. These observations demonstrate the structural diversity and fluxionality of the subnanometer Pt clusters that will have important implications for catalysis.