Vibrationally reserved photoelectron spectroscopy of silicon cluster anions Sin- (n=3-7)

Photoelectron spectra of Si-n(-) (n=3-7) have been measured at several photodetachment energies. The anions were created using a pulsed discharge source, resulting in considerably colder clusters than in earlier work. As a result, vibrationally resolved spectra were obtained for larger clusters and more electronic states than in previous studies of these species, leading to more accurate electron affinities, term energies, and vibrational frequencies for the ground and excited electronic states of the neutral clusters. The assignments of excited states were aided by ab initio calculations and photoelectron angular distributions. (C) 1998 American Institute of Physics. [S0021-9606(98)02703-2].