If the exact canonical SMILES is not found in the fragment database, the fragment is tested against the SMARTS patterns of general ring fragments in the auxiliary database. If a fragment is not found in both databases, the atoms are handled by the rules-based atom-by-atom builder. In the set of 4,548 Platinum compounds, there were 9,741 fragments which have at least five atoms, and 7,852 (80.6%) of fragments are found in the COD-based rigid fragment database, 1,887 (19.4%) are partially found in general ring database, and only two fragments are not found in either database.