This three-year, $395,000 National Science Foundation Division of Materials Research Project Grant supports theoretical and computational research aimed at rationally designing novel hydrogen-rich superconductors. The principal investigator will use quantum mechanical calculations and first-principles modeling techniques to computationally predict crystal structures of hydrides that could be synthesized under pressure and study their electronic properties and superconducting potential. A focus is ternary hydrides' phase diagrams as a function of pressure. Predictions will be confirmed by experimental collaborators. The award also advances open-source crystal structure prediction software Xtalopt and the Avogadro chemical modeling program. Graduate and undergraduate students will receive training in computational materials design and programming to prepare them for careers at the intersection of theory, computation and experiment. Undergraduate researchers from minority-serving institutions will also gain exposure to research opportunities in STEM fields through faculty and student exchanges. This Project Grant from the NSF Mathematical and Physical Sciences program will contribute to the development of cyberinfrastructure to enable current and future scientific discoveries.