The Gibbs energy, G, determines the equilibrium conditions of chemical reactions and materials stability. Despite this fundamental and ubiquitous role, G has been tabulated for only a small fraction of known inorganic compounds, impeding a comprehensive perspective on the effects of temperature and composition on materials stability and synthesizability. Here, we use the SISSO (sure independence screening and sparsifying operator) approach to identify a simple and accurate descriptor to predict G for stoichiometric inorganic compounds with ~50 meV atom−1 (~1 kcal mol−1) resolution, and with minimal computational cost, for temperatures ranging from 300–1800 K. We then apply this descriptor to ~30,000 known materials curated from the Inorganic Crystal Structure Database (ICSD). Using the resulting predicted thermochemical data, we generate thousands of temperature-dependent phase diagrams to provide insights into the effects of temperature and composition on materials synthesizability and stability and to establish the temperature-dependent scale of metastability for inorganic compounds.

Oxygen vacancies (V(O)) in oxides are extensively used to manipulate vital material properties. Although methods to predict defect formation energies have advanced significantly, an understanding of the intrinsic material properties that govern defect energetics lags. We use first-principles calculations to study the connection between intrinsic (bulk) material properties and the energy to form a single, charge neutral oxygen vacancy (E(V)). We investigate 45 binary and ternary oxides and find that a simple model which combines (i) the oxide enthalpy of formation (ΔH(f)), (ii) the midgap energy relative to the O 2p band center (E(O 2p) + (1/2)E(g)), and (iii) atomic electronegativities reproduces calculated E(V) within ∼0.2 eV. This result provides both valuable insights into the key properties influencing E(V) and a direct method to predict E(V). We then predict the E(V) of ∼1800 oxides and validate the predictive nature of our approach against direct defect calculations for a subset of 18 randomly selected materials.

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