The structural and electronic properties of small AumNin (m＋n≤6) clusters have been studied at the UBP86/LANL2DZ and UBP86/def2-TZVP levels, respectively. Structural features, binding energies, vertical ionization potentials, vertical electron affinity, charge transfers, and binding characters were evaluated for each Au—Ni binary cluster. In all of the Au—Ni binary clusters, the nickel atoms are brought together, yielding the most Ni—Ni bonds, and the gold atoms are located around a Ni core with the most Au—Ni bonds. The vertical ionization potentials, vertical electron affinity, and Fermi level of the Au-rich clusters are similar to the pure gold clusters, demonstrating an odd-even oscillation. A very large electronic charge transfer from Ni to Au was found in the binary clusters. The spin density is located on Ni atoms in the Au-rich clusters, while the gold atoms are spin-polarized in the Ni-rich clusters. The partial density of state of the Au—Ni binary clusters makes it clear that the reactivity of the Au—Ni binary clusters toward the small molecule is higher than that of the pure gold clusters.

Key words: gold-nickel cluster, vertical ionization potential, vertical electron affinity, density of state (DOS), density functional theory