Molecule Selection. We used the CSD's ConQuest software and Python API (1) to search the CSD for crystal structures of rigid molecules to which our CSP methods could be applied on a very large scale. Restricting our search to solved crystal structures (i.e. with coordinates for all atoms in the asymmetric unit) of single chemical species (no cocrystals, solvates, inclusion compounds), we additionally filtered structures based on the following criteria: containing only elements from C, H, N, O, F; Z ≤ 1; molecular weight less than 230; and importantly containing no rotatable bonds (as defined by the CSD's internal criteria).