Cluster geometries from density functional calculations – prospects and limitations

Abstract.

The use of density functional methods to calculate the structures and energies of clusters of atoms is discussed. Applications to phosphorus and sulphur show that unexpected structures occur even in small clusters. Calculations of many isomers of carbon clusters from C₄ to C₃₂ (n even) show striking results, with periodic patterns in several structural classes. Gradient corrections are significant, but regular within a given cluster type. Some strengths and limitations of the approach are discussed.