title: Density functional study of structural and electronic properties of bimetallic copper-gold clusters: comparison with pure and doped gold clusters.
abstract: The geometrical structures, relative stabilities, and electronic properties of small bare gold clusters Au(n)(lambda) and bimetallic complexes of bare metal clusters with one copper atom Au(n-1)Cu(lambda) (charge lambda = 0, +1, -1; 2 < or = n < or = 9) have been systematically investigated by means of first-principles density functional calculations at the B3LYP level. The results show that the most stable isomers have a planar structure and resemble pure gold clusters in shape, and no three-dimensional isomers were obtained for neutral and anionic doped gold clusters. However, the geometries of Au(n-1)Cu(+) are found to undergo a structural change from two dimensional to three dimensional when the cluster contains 7 atoms. The calculated dissociation energy and second difference energy as a function of the cluster size exhibit a pronounced even-odd alternation phenomenon. Ionization potentials and electron detachment energies (both vertical and adiabatic) of Au(n)(lambda) and Au(n-1)Cu(lambda) clusters are discussed and compared with available experimental results. A good agreement between experimental and theoretical results suggests good prediction of the lowest energy structures for all clusters calculated in the present study.
authors.affiliation: Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, China.
authors.forename: Huai-Qian
authors.initials: HQ
authors.lastname: Wang
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Kuang
authors.forename: Hui-Fang
authors.initials: HF
authors.lastname: Li