Reactivity of AlnC clusters with oxygen:: search for new magic clusters

Theoretical electronic structure studies of the geometries, binding energies and electron affinities of anionic and neutral AlnC (n = 1-8) clusters are carried out to understand the recent experiments on the reactivity of AlnC clusters with oxygen. Our studies, based on an all-electron gradient-corrected density-functional formalism, show that anionic clusters where the total energy required to remove an electron and an Al atom is less than 5.7 eV, react with O-2 molecules. An Al7C- cluster observed as a stable species in these experiments has a high electron affinity and may be an ideal choice for cluster-assembled materials. (C) 2000 Elsevier Science B.V. All rights reserved.