Technically, the diffvap crystal dataset features a priori known constraints on the reagent concentration space and the nature of the automated experiments. The α vial solution results from mixing a stock solution of organic halide, a stock solution of organic halide and lead halide, formic acid, and the required amount of solvent to reach the desired concentrations. Thus the composition of the α vial is constrained to the convex hull defined by the stock solution composition, which are in turn limited by the solubility of the lead halide and organoammonium halide salts. Although optimization over constrained domains is within the ability of several experiment planners in Olympus, we do not provide a known constraints module here, and reserve its implementation for future work. Instead, we assign infeasible compositions (the compositions cannot be reached using stock solutions) with the least desirable crystal score, clear solution.