The electronic structure of amorphous silicon nanoclusters is calculat
ed within the empirical tight-binding approximation. The electronic st
ates are classified into three groups: extended and weakly and strongl
y localized. The last category practically disappears in hydrogenated
amorphous silicon clusters for which the blueshift is comparable to wh
at is predicted for crystallites. The radiative recombination rates ar
e comparable for small clusters (similar to 1 nm) but 2 orders of magn
itude higher for larger clusters (similar to 2 nm) of the amorphous ph
ase due to disorder induced breaking of selection rules.