As with SMARTY, AlkEthOH provides a useful toy example for testing our methods, and SMIRKY is successful based on total scores for all fragment types. In smirnoff99Frosst, there are nonbonded parameters corresponding to the same hydrogen parm99/parm@frosst atom types discussed above (Section 3.1.1). To distinguish all of these types, multiple beta position atoms must be identified. a total score of 100% for all smirnoff99Frosst fragment types in AlkEthOH (Table ). An average total score of > 90% at multiple temperatures provides further evidence of SMIRKY's success (Table ). While SMIRKY is quite successful in general, its success is not universal at all temperatures. At moderate temperatures, SMIRKY is able to discover SMIRKS patterns complex enough to agree with the fragment typing used in smirnoff99Frosst, achieving a successful total score of 100%. But, as is expected with an MC algorithm, we achieve relatively poor scores both at = 0 and at the high temperature of 0.1. However, at the intermediate temperature of 0.001, SMIRKY eventually generates torsion SMIRKS with a 100% score and maintains that high score (Figure ). In addition to the examples depicted here, multiple simulations at the temperatures of 10 -6 , 10 -5 , and 0.0001 also reached a 100% total score. The fact that multiple temperatures reach a total score of 100% indicates we have been successful in automatically sampling the chemical perception trees for torsion parameters in AlkEthOH. Details for all simulations are included in the Additional Information.