ELECTRONIC AND GEOMETRICAL STRUCTURE OF NOBLE-METAL CLUSTERS

We investigate the electronic and structural properties of small (N le ss than or similar 20) and medium sized (N less than or similar 500) c lusters of Cu, using the first principles Tight-Binding Linear Muffin- Tin Orbitals (TB-LMTO) method in connection with the real-space recurs ion scheme. We find the electronic structure resembling the one of sim ple alkali metal clusters: Pronounced shell closing effects can be ide ntified in the ionization potentials as well as in the HOMO-LUMO gaps for the magic sizes N = 8, 20, 34 and 40. The low-energy equilibrium g eometries show considerable Jahn-Teller distortions, just as in the ca se of alkali metals.