The Structures of Ag55+and Ag55-: Trapped Ion Electron Diffraction and Density Functional Theory

Abstract

We report the experimental structure determination of cold, mass selected Ag₅₅^+/- cluster ions using the recently developed technique of trapped ion electron diffraction. By comparison of experimental and theoretical molecular scattering functions and consideration of computed total energies, we show that Ag₅₅⁺ constitutes an ideal Mackay icosahedron, whereas Ag₅₅^- is a weakly Jahn−Teller distorted icosahedron. Isomers of other structural types, for example, decahedral or close-packed, could be ruled out. The candidate structures were obtained by density functional theory calculations.