Design and energetic characterization of ZnO clusters from first-principles calculations

The energetics, stable configurations and electronic structures of the (ZnO)n(ZnO)n clusters for n ranging from 9 to 64 have been studied by using first-principles calculations. The formation energy of the bubble-like (b-)clusters decreases with the increase of cluster size n  , and exhibits an approximately linear relationship to 1/n1/n for n>16n>16. The b-clusters are energetically more favorable than the wurzite-derived (w  -)clusters for n<26n<26, but become less stable than the w  -clusters for n⩾26n⩾26. The HOMO-LUMO gap of the w-clusters is narrower than that of the b-clusters.