Fig. 21From: PubChem chemical structure standardizationDifferences between PubChem-standardized and InChI-derived structures—functional groups. The y-axis indicates the number of affected substances (not the absolute number of modifications in a substance) in the Verify Functional Groups step during the PubChem standardization of InChI-derived structures. Transformation indices represent respective standardization rules used to normalize non-standard functional group configurations (see the “Methods” section). All non-visible bars indicate zero affected substancesBack to article page