For the ceria supported global minima (shown in Figure ), the same structural motifs are present. However, the presence of the cerium oxide surface impedes the formation of strictly planar structures. Platinum atoms bind to oxygen atoms of the ceria surface and the oxygen atoms of the particle tend to locate near Ce. Since, distances between oxygen atoms in the ceria surface (~4.0 Å) are larger than the Pt-Pt bond distances (2.4 Å fully reduced, ~2.6 Å with an oxygen in bridged position), there is a size mismatch that causes the smaller particles to adopt triangular conformations where only two platinum atoms are in contact with the surface or angled conformations which allow a better fit.