We model the structures and energies of (ZnS)(n) clusters, where n = 18-560. We employ two computational techniques-interatomic potential methods with simulated annealing and density functional theory; both give similar results. Clusters between n = 18 and 49 adopt hollow geometries in which all atoms are three coordinated (denoted bubbles), confirming previous studies. Clusters between n = 50 and 80 show onion-like structures in which one bubble is inside another. Simulated annealing simulations on (ZnS)(256) and (ZnS)(512) in vacuo yielded crystalline clusters in which the crystal phase is not any of the two observed bulk phases of ZnS (zincblende and wurtzite), but a new one, which has the topology of the BCT zeolite. For clusters between n = 80 and 560 we study clusters generated from the three crystalline phases. The lowest energies are for those with BCT structure, followed closely by the wurtzite clusters, while zincblende clusters are the least stable. (c) 2006 Elsevier B.V. All rights reserved.