Structural and bonding properties of ScSi−n (n = 2 ∼ 6) clusters: photoelectron spectroscopy and density functional calculations

Abstract

Anion ion photoelectron spectroscopy and density functional theory (DFT) are used to investigate the electronic and structural properties of ScSi−n (n = 2 ∼ 6) clusters and their neutrals. We find that the structures of ScSi−n are similar to those of Si−n+1. The most stable isomers of ScSi−n cluster anions and their neutrals are similar for n = 2, 3 and 5 but different for n=4 and 6, indicating that the charge effect on geometry is size dependent for small scandium-silicon clusters. The low electron binding energy (EBE) tails observed in the spectra of ScSi−4,6 can be explained by the existence of less stable isomers. A comparison between ScSi−n and VSi−n clusters shows the effects of metal size and electron configuration on cluster geometries.