The efficient generation of constitutional isomers of a given molecular formula has been a core area of cheminformatics research for decades . Such molecular generation methods can be used as hypothesis generators in areas such as computer-assisted structure elucidation, but also to answer broader questions such as the exact size of a chemical space. Structure generators that produce constitutional isomers take a molecular formula as input, e.g., C 10 H 16 O, and enumerate or output all possible chemical structures that can be built with the given set of atoms in the molecular formula. The history of chemical graph generators reaches back to the 1960s and has recently been reviewed in detail .