Figure 1
From: Efficient enumeration of monocyclic chemical graphs with given path frequencies
Example of a chemical structure and its feature vector. In this example, a feature vector consists of the number of occurrences of each atom type and each bond type (e.g., C2C denote the double bond between two carbon atoms). Note that the entry of C1C is 8 because each bond is counted for both directions. Since there may exist multiple structures with the same feature vector, enumeration of such structures is required.