The electronic and geometrical structures of the ground and some low-lying excited states of the SiCln and SiCln- series, n = 1-5, are calculated within a local spin density approximation (LSDA) augmented with the nonlocal gradient corrections to the exchange functional. Energies of fragmentation through different decay channels are evaluated for both series, and an estimation of the electronic affinity for all the neutral silicon chlorides is made for the first time. All the anions considered are found to have excited states which are stable toward dissociation, except for SiCl2-. According to the results of the calculations, the stability of the SiCl5 radical is near zero threshold, whereas its anion is rather stable and possesses a dissociation energy of about 30 kcal/mol.