Density Functional Study of Structural and Electronic Properties of Maximum-Spin n+1Aun-1Ag Clusters

摘要

The structures and relative stabilities of high-spin n+1Aun-1Ag and (Aun-1Ag+)-Au-n (n = 2-8) clusters have been studied with density functional calculation. We predicted the existence of a number of previously unknown isomers. Our results revealed that all structures of high-spin neutral or cationic Aun-1Ag clusters can be understood as a substitution of an Au atom by an Ag atom in the high-spin neutral or cationic Au,, clusters. The properties of mixed gold-silver clusters are strongly sized and structural dependence. The high-spin bimetallic clusters tend to be holding three-dimensional geometry rather than planar form represented in their low-spin situations. Silver atom prefers to occupy those peripheral positions until to n = 8 for high-spin clusters, which is different from its position occupied by light atom in the low-spin situations. Our theoretical calculations indicated that in various high-spin Aun-1Ag neutral and cationic species, (Au3Ag)-Au-5, (AuAg)-Au-3 and (Au4Ag+)-Au-5 hold high stability, which can be explained by valence bond theory.