title: Structures of medium-sized ruthenium clusters: the octahedral motif.
abstract: We describe the first direct structural characterization of medium-sized ruthenium clusters (Ru19 (-) , Ru28 (-) , Ru38 (-) , and Ru44 (-) ) by using a combination of trapped ion electron diffraction and density functional theory. We find close-packed structures based on octahedral geometries: Ru19 (-) and Ru44 (-) are closed-shell octahedra whereas Ru28 (-) is a double octahedron. In the case of Ru38 (-) , instead of a truncated octahedron we obtain evidence for lower symmetry structures containing a reentrant surface.
authors.affiliation: Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Karlsruhe (Germany).
authors.forename: Eugen
authors.initials: E
authors.lastname: Waldt
authors.forename: Reinhart
authors.initials: R
authors.lastname: Ahlrichs
authors.forename: Manfred M
authors.initials: MM
authors.lastname: Kappes
authors.forename: Detlef
authors.initials: D
authors.lastname: Schooss
keywords: cluster structure; density functional theory; electron diffraction; octahedral geometries; ruthenium