We describe a semiclassical molecular-dynamics procedure suitable for
charged or neutral clusters of sodium containing up to several hundred
atoms. The charged liquid drop energy parameters of the model are ext
racted, and shown to be in good agreement with empirically inferred va
lues. Vertical ionization energies are also found to be in good agreem
ent with experiment. We find that the time-averaged ionic density beco
mes jelliumlike with a diffuse surface when the cluster is liquid, and
discuss the time-averaged net charge of charged clusters. Clusters fr
om size 8 and up an found to have collective ionic monopole oscillatio
ns at a sharp frequency close to that predicted by a compressible liqu
id drop model. Also, low-frequency shape oscillations occur at frequen
cies consistent with an incompressible liquid drop model. We discuss t
he temperature dependence of the surface energy predicted by the model
.