Structure, stability, and vibrational properties of small silver cluster

The ground state geometries and binding energies of small silver clusters were found using Density Functional Theory (DFT) methods. We have compared various non local corrections for exchange and correlation energies, with or without treating explicitely all the electrons. The transferability of standard effective core potentials (ECP) is good, as far as their core size is small enough. From these results, and after comparison with ab initio CI one electron- ECP calculations, we have concluded to the ability of describing small silver clusters as one-electron systems. Thus, we have parametrized our distance-dependent tight- binding hamiltonian (DDTB), previously applied to alkali clusters. The geometries and energies provided by the model are very close to those found in ab initio calculations when available, that is, up to Ag-9. We have also computed the harmonic frequencies of small silver clusters.