DFT calculations were performed to optimize the structure of each spinel oxide in this database and calculate their energies. Every DFT calculation in this study was performed with the Vienna ab-initio Simulation Package (VASP). The Projector-Augmented Wave (PAW) method was used to model the core electrons . The Perdew-Burke-Ernzerhof functional which utilizes the generalized gradient approximation approach was used to describe the exchange-correlation effects . For spinel oxides containing 3d metal elements with the exception of Zn, spin-polarized DFT calculations were performed; for all other materials non spin-polarized calculations were performed instead. The Hubbard U correction was employed for materials containing 3d transition metals; the exact values used in this study are described in Supplementary Table . The energy cut-off used in these calculations was 520eV. Each and every single one of these parameters was optimized to ensure that the right balance between computational cost and accuracy was achieved.