The computational design of molecules with specific profiles is a key scientific and technological challenge 1 across many important application areas from catalysis and energy storage, to the design of pharmaceutical drugs. This task is complicated by the very large size of chemical space , and the requirement to fulfil multiple design criteria (multiparameter optimization, MPO). In drug design, candidate molecules must be active against an intended target but also possess suitable physicochemical, metabolic and safety profiles. Despite advances in automated chemical synthesis, the scale of chemical space makes computational evaluation of candidate molecules essential for accelerating molecular discovery . Traditional virtual screening (VS) involves exhaustively evaluating a large library of molecules (up to billions ) to identify candidates with the desired predicted properties, called hits, which comprise a small fraction of the total library that is screened.