Top-10 most frequent ‘augmented atoms’ in PubChem Compound. PubChem Compound records were fragmented with atom type and bond type definitions identical to those used by Adamson et al. . Incidence was used for ranking, calculated based on 46,605,207 compound records. Dashed lines indicate aromatic bonds as perceived using the aromaticity model OEAroModelMDL in the OpenEye Scientific Software, Inc. OEChem C++ toolkit .