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.

The golden Au16(q) (q = 0, -1) cage is doped systematically with an external atom of different valence electrons: Sc, Ti, and V. The structural, electronic, and magnetic properties of the doped clusters, M@Au16(q) (M = Sc, Ti and V; q = 0, -1) are investigated using the Saunders "Kick" (SK) global search technique combined with density-functional theory (DFT) calculations (SK-DFT). It is found that the closeness of the calculated vertical/adiabatic detachment energy for Ti-doped and V-doped (3.09/3.16 eV for Ti-doped, and 3.31/3.38 eV for V-doped) is consistent with the negligible geometry change between the anionic and neutral ground state structures. The characteristics of the Sc@Au16(-) cluster includes its remarkably high average binding energy and doping energy, which reflects its high stability. The different spectral features between doped M@Au16(-) and pure Au16(-) clusters indicate endohedral structures with larger distortion from the parent Au16(-) cage for the doped clusters. The s electrons of the Au16 cage are observed to transfer to Sc, Ti and V atom for doped M@Au16(q) clusters by natural population analysis (NPA). The magnetic moment of the impurity Sc/Ti/V atom is somewhat quenched. Furthermore, the electron localization function analysis does not reveal strong interactions. The current work shows that the electronic properties of the golden cage can be systematically tuned through doping.

A systematic structure and property investigation of MnGen− (n = 3–14) was conducted by means of density functional theory coupled with mass-selected anion photoelectron spectroscopy. This combined theoretical and experimental study allows global minimum and coexistence structures to be identified. It is found that the pentagonal bipyramid shape is the basic framework for the nascent growth process of MnGen− (n = 3–10), and from n = 10, the endohedral structures can be found. For n = 12, the anion MnGe12− cluster probably includes two isomers: a major isomer with a puckered hexagonal prism geometry and a minor isomer with a distorted icosahedron geometry. Specifically, the puckered hexagonal prism isomer follows the Wade–Mingos rules and can be suggested as a new kind of superatom with the magnetic property. Furthermore, the results of adaptive natural density partitioning and deformation density analyses suggest a polar covalent interaction between Ge and Mn for endohedral clusters of MnGe12−. The spin density and natural population analysis indicate that MnGen− clusters have high magnetic moments localized on Mn. The density of states diagram visually shows the significant spin polarization for endohedral structures and reveals the weak interaction between the Ge 4p orbital and the 4s, 3d orbitals of Mn.

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