Semiclassical approach to metal cluster dynamics

We show that semiclassical methods provide a valid description for the elec tronic and ionic dynamical response of metal clusters in the regime of high excitation energies. We consider real time dynamics for electrons at a Vla sov-LDA level and include dynamical correlations by an Uhling-Uhlenbeck col lision term. Coupling to ionic motion is explicitly accounted for by means of a pseudo potential. It is found that electron-electron collisions are mo re important than electron-ion collisions for determining the width of the plasmon response at high excitation energies. The coupling to true ionic mo tion yields non-adiabatic molecular dynamics which is validated on the pico second time scale.