We select the last snapshots from the previous molecular dynamics run for all our oxygen ratios and perform geometry optimizations. For comparison, we also perform geometry optimizations using the recent MACE-MP-0 model using the same geometries. We quickly An example of the process is shown in Figure where the Pt 6 O 8 species is packed back together with the rest of the nanoparticle. Although geometry optimizing will only partially change the initial geometry from ReaxFF, these results indicate that MACE-MP-0 would give geometries that do not include Pt 6 O 8 species. In order to systematically compare geometries between the two forcefields we define the concept of sphericity score which quantifies the deviation from a perfect spherical shape by calculating the variance in the distances between the centroid and the platinum atoms at the nanoparticle surface.