Electronic and geometrical structure of (GaAs)(n) clusters for n = 12, 36, 48, 54, and 60 together with related clusters (BN)(12), (CdS)(12), (CdSe)(12), (CdTe)(12), and C-108 are computed using density functional theory with generalized gradient approximation. Our results show for the first time that GaAs clusters do possess an exceptional capability to bind extra electrons. The extra electrons in the GaAs dianions appear to occupy valence-like states. (C) 2009 Elsevier B.V. All rights reserved.