Figure 1From: Structure-based classification and ontology in chemistrySimilarity-based hierarchical structure clustering. Similarity-based hierarchical structure clustering is illustrated as it is computed in PubChem [14]. The figure was generated by searching for 'aspirin' and then executing the 'Structure Clustering' tool from the menu at the right. Numbers on the right are compound identifiers, unique numbers associated with chemical structures within the PubChem database.Back to article page