Comparative study of the structures of copper, silver, and gold icosamers: Influence of metal type and charge state

We present a comparative study on the structural properties of the coinage metal icosamers Cu-20(+/-), Ag-20(+/-), and Au-20(+/-). Using trapped ion electron diffraction measurements in combination with density functional structure calculations we find distinct structural differences depending on the cluster material and the charge state: Cu-20(-), Cu-20(+), as well as Ag-20(+) prefer icosahedral structures. Ag-20(-) adopts a rearranged, distorted icosahedral structure. While Au-20(-) is tetrahedral, Au-20(+) cannot be described satisfyingly by a single isomer alone. Here a mixture of tetrahedral and distorted icosahedral structures is suggested. The influence of material and charge on the structural properties of the coinage metal icosamers is discussed. (C) 2008 American Institute of Physics. [DOI: 10.1063/1.2992073]