Structures and growth modes of (TiO)n (n⩽9) clusters

We study the equilibrium geometries and growth modes of small stoichiometric (TiO)n (n⩽9) clusters by using the ab initio calculations within the framework of density-functional theory and the generalized gradient approximation. The resulting geometries show that the three-dimensional ring-like structures are more favorable energetically than the cubic-like structures and clusters of (TiO)6 and (TiO)9 have an unusual stability. Moreover, studies show that even larger clusters could be obtained by using (TiO)2 and (TiO)3 rings as the building blocks.