Exploration of multiple energy landscapes for zirconia nanoclusters

We have predicted the stable and low-energy metastable structures for (ZrO2) n clusters, where n = 1 to 12, employing Density Functional Theory (DFT) at the PBEsol0 level. A process of data mining and the application of an evolutionary algorithm to three different energy landscapes, as defined by interatomic potentials, for each cluster size, was used to generated the plausible structures for refinement using DFT at the PBEsol level. The structures for zirconia were found to be similar to that predicted for titania except that the order, with respect to the binding energies, of the configurations for the two compounds were different for the larger sized clusters. The energies of the local minima configurations and their respective HOMO and LUMO are discussed, as well as the insights gained from employing more than one set of interatomic potentials in the initial global optimisations.