Most materials inevitably oxidize in terrestrial environments. However, oxidation into a self-passivating phase can protect the bulk from further decomposition. To be effective, the selfpassivating phase must be thermodynamically stable with respect to further oxidation and mechanically matched to the parent material to form a continuous layer that blocks further oxygen. The former can be estimated by determining the most stable phases upon decomposition in oxygen, and the latter by empirical rules such as the Pilling-Bedworth ratio (PBR) (i.e., that the ratio in the molar volume of the two materials is between 1 and 2). Online databases, such as the AFlowLib, OQMD, and Materials Project (MP), provide ab initio predictions of the enthalpy of formation and molar volumes of materials that can be used to estimate these properties, but analyzing these large datasets is computationally challenging.