In Search of Structure’ Links Across Length Scales: Crossover Among Structural Motifs, Energetics, and Magic Systems in Subnanometer Transition Metals Clusters

Clusters of transition metal (TM) elements are becoming increasingly important in our daily lives for a wide ensemble of applications in catalysis and bio-fields, for health, energy and environmental problems. To help build structure/property relationships for these critical materials, it is presented here, first, a systematic study and descriptor-based classification of the structure, energetics, and quantum properties of TM tetramers and hexamers via first-principles simulations. Then, the obtained database is analyzed to single out trends in energetic and structural quantities, and their connections with the corresponding quantities of macroscopic bulk and larger clusters. It is found that the correlations between the micro and the macro scale do exist, providing recognizable evolution patterns in terms of both size and atomic number. At the same time, exceptions to the observed trends (outliers), are encountered including “magic” or on the opposite fluxional clusters, and an effort to rationalize their occurrence in terms of electronic structure considerations is made.