Isomer dynamics of the [Au6(NHC-S)4]2+ nanocluster

The use of metal nanoclusters is strongly reliant on their size and configuration; hence, studying the potential isomers of a cluster is extremely beneficial in understanding their performance. In general, the prediction and identification of isomer structures and their properties can be challenging and computationally expensive. Our work describes an investigation to find local isomers for the previously experimentally characterized small gold cluster [Au6(NHC-S)4]2+ protected by bidentate mixed carbene-thiolate ligands. We employ the molecular dynamics simulation method where the interatomic forces are calculated from density functional theory. We find several isomers that are more stable than the isomer corresponding to the experimental crystal structure, as well as a significant impact of the finite-temperature atom dynamics on the electronic structure and optical properties. Our work highlights the growing need to investigate ligand-stabilized metal clusters to uncover isomerism and temperature effects on their properties.