A recently developed method for time-dependent quantum simulations of large
systems on short time scales is applied to the dynamics following electron
photodetachment from the clusters I-(Ar)2 and I-(Ar)12. The problem is treated
in full dimensionality, incorporating all vibrational degrees of freedom, by
the classically based separable potential (CSP) approach. This is essentially
an approximate time-dependent quantization of classical dynamics: Classical
molecular dynamics is used to generate effective, single mode separable time-
dependent potentials for each degree of freedom. The quantum dynamics is then
propagated separately for each mode, using the effective potentials that
implicitly include effects such as energy transfer between the modes. In the
current application of the CSP method we calculate properties relevant for the
interpretation of spectroscopies, such as correlation functions of wave packets,
as well as time-dependent atom-atom distribution functions, pertinent to future
diffraction experiments using ultrafast pulses. The insight obtained from the
quantum dynamics of these clusters is discussed. In particular, light is thrown
on the difference in the dynamics associated with the system landing on the three 
different electronic surfaces of the neutral I(2P).(Ar)n system.