In the next step of the high-throughput workflow, the thermodynamic stability of each composition was assessed. First, the energies of the normal and the inverse spinel structures of each composition were compared to determine the most probable ground-state configuration of each composition, with the more stable one being chosen for the next step. Then, we constructed a convex hull based on the bulk energies of all known materials encompassing the phase space of the elements that constitute each spinel oxide composition. The Open Quantum Materials Database was used to construct the phase space of the elements that constitute each compound . The thermodynamic stability of each composition was subsequently determined by calculating the distance of the bulk energy of each composition from this convex hull. The total energy of each compound was compared to a linear combination of possible decomposition products that lie on the convex hull Figure : A) Scheme describing the computational workflow to identify new catalysts for OER. In this workflow, Co2.5Ga0.5O4 was discovered as a highly-performing spinel oxide catalyst. B) Diagram describing the structure of a spinel oxide AB2O4, where A is tetrahedrally coordinated and B is octahedrally coordinated of the phase space in order to calculate this distance from the convex hull . If the difference between the energies was within 0.030 eV/atom (30meV/atom), the compound would be considered thermodynamically stable .