The second test for this approach is establishing if the method can build a SMARTS hierarchy that represents the labels assigned by a different chemical perception model not based on SMARTS. This test is successful if the each SMARTS in the hierarchy maps to exactly one label. We conduct this test by using GAFF as the perception model, and we seek to determine a SMARTS hierarchy that can assign GAFF types that is indistinguishable from using antechamber to assign GAFF types. This test examines whether this approach can search SMARTS space effectively enough to work on a successful, mature perception model.