Inverse design of stable hybrid organic-inorganic halide perovskite materials Perovskite solar cells are a class of light-harvesting material which are typically characterized by inorganic lead halide matrices with inorganic or organic ions. Via the optimization of thin-film manufacturing and device architectures, perovskite materials have achieved revolutionary cell efficiencies in a matter of several years. Hybrid organic-inorganic perovskites (HOIPs), perhaps most notably methylammonium lead iodide (MAPbI 3 ), constitute a class of perovskite absorbers which are easy/cheap to manufacture and highly efficient. However, toxicity and stability issues continue to inhibit the large-scale adoption of HOIPs in commercially viable photovoltaics. With the goal of identifying thermodynamically stable perosvskites that preserve the band gaps and charge transport properties of MAPbI form A + B 2+ X - 3 (Fig. ). The goal of the screening was threefold: i) discover thermodynamically stable compounds with respect to the convex hull of stability, ii) preserve small effective masses (inversely proportional to the mobilities of charge carriers), and iii) preserve optimal band gaps for photovoltaics.