Density functional theory calculations have been conducted on 20- and 32-atom dodecahedral and face-capped dodecahedral cage clusters of beryllium and silicon. Stable Be24Si8, Be12Si8 and Be12Si20 cages are described, as is a stuffed cluster consisting of dodecahedral Si-20 with an endohedral icosahedral Be-12. Especial stability is associated with clusters in which faces are capped by silicon atoms, acting as electron donors to beryllium atoms. (C) 2012 Elsevier B.V. All rights reserved.