  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 kcal/mol) 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.
