Density functional study of structural and electronic properties of small bimetallic silver - Nickel clusters

Theoretical study on the structure and electronic properties of small Ag_mNi_p (m + p ≤ 6) clusters has been carried out in the framework of density functional theory. Structural features, cohesive energies, vertical ionization potentials, and charge transfers are evaluated for each Ag/Ni ratio. In all the Ag_mNi_p clusters, the nickel atoms are brought together, yielding a maximum of Ni-Ni bonds, and the silver atoms are located around a Ni core with a maximum of Ag - Ni bonds. The ionization potential and the highest occupied molecular orbital shape are directly related to the two- or three-dimensional character of the cluster's geometry. A very low electronic charge transfer from Ni to Ag is found, and the magnetic moment is located on Ni atoms but with a low spin polarization on silver in the Ni-rich clusters.