− and Cun − with n=20–40:

Abstract. Cold, size selected sodium and copper cluster anions have been studied by photoelectron spec-troscopy. The structure of the uppermost part of the s-band of the copper clusters turns out to be close to identical to the one observed in the density of states of sodium clusters of the same size. This result indicates that in the studied size range sodium and copper clusters adopt the same geometries, and that electron-lattice interaction is of comparable strength in both systems. The observed s-band level density scales almost perfectly with the bulk Fermi energies of the materials, which demonstrates that close to the threshold both systems follow the same electron dispersion relation. PACS. 33.60.Cv Ultraviolet and vacuum ultraviolet photoelectron spectra – 36.40.Cg Electronic and magnetic properties of clusters – 73.22.-f Electronic structure of nanoscale materials: clusters, nanoparticles, nanotubes, and nanocrystals