Density-functional investigation of 3d,4d,5d impurity doped Au₆ clusters

The general features of the geometries and electronic properties for 3d, 4d, and 5d transition-metal atom doped Au_6 clusters are systematically investigated by using relativistic all-electron density functional theory in the generalized gradient approximation (GGA). A number of structural isomers are considered to search the lowest-energy structures of M@Au_6 clusters (M=3d, 4d and 5d transition-metal atoms), and the transition metal atom locating in the centre of an Au_6 ring is found to be in the ground state for all the M@Au_6 clusters. All doped clusters, expect for Pd@Au_6, show large relative binding energies compared with a pure Au_7 cluster, indicating that doping by 3d, 4d, 5d transition-metal atoms could stabilize the Au_6 ring and promote the formation of a new binary alloy cluster.