Geometries, stabilities, and electronic properties of Pt-group-doped goldclusters, their relationship to cluster size, and comparison with pure goldclusters

Abstract

A systematic study of bimetallic Au_nM₂ (n = 1–6, M = Ni, Pd, and Pt) clusters is performed by using density functional theory at the B3LYP level. The geometric structures, relative stabilities, HOMO–LUMO gaps, natural charges and electronic magnetic moments of these clusters are investigated, and compared with pure goldclusters. The results indicate that the properties of Au_nM₂clusters for n = 1–3 diverge more from pure goldclusters, while those for n = 4–6 show good agreement with Au_nclusters. The dissociation energies, the second-order difference of energies, and HOMO–LUMO energy gaps, exhibiting an odd–even alternation, indicate that the Au₄M₂clusters are the most stable structures for Au_nM₂ (n = 1–6, M = Ni, Pd, and Pt) clusters. Moreover, we predict that the average atomic binding energies of these clusters should tend to a limit in the range 1.56–2.00 eV.