3. The geometries are then subjected to an additional 100 ns of NVT simulations at 350K. This is done to amplify potential geometrical features such as small platinum-oxide clusters that were previously observed in past studies using similar forcefields. The grand canonical Monte Carlo moves are stopped, and the system is allowed to relax in the canonical ensemble. and is trained on the Material Project database. MACE was recently benchmarked to be one of the most accurate forcefield to predict the energetics of materials across the periodic table. 5. DFT calculations are then performed on the relaxed geometries by both forcefields to Figure : The computational workflow followed in this study. Monte Carlo simulations provide initial configurations, Molecular Dynamics simulations are then performed to relax the geometries and further explore the phase space. Finally, ONETEP linear-scaling DFT calculations are carried out to obtain the electronic structure and refined energetics of the oxidized nanoparticles. compare them and obtain the electronic structure of the oxidized nanoparticles. Computationally elucidating the electronic structure of such large platinum nanoparticles remains a challenging task, often hindered by the computational expense associated with such calculations. We overcome these limitations by using the ONETEP linear-scaling DFT software, which exhibits a linear scaling behavior with respect to the number of atoms. This enables us to readily access electronic structure calculations for a wide range of nanoparticle sizes and configurations. Additional computational details for all the methods involved are provided in the supplementary information.