It is of interest to compare the results between αCD and βCD by focusing on the ten guests for which experimental data are available with both hosts. The SMIRNOFF99Frosst and GAFF 1.7 force fields both yield somewhat more accurate binding affinities for αCD (RMSE = 0.8 [0.5, 1.1] kcal/mol) than for βCD (RMSE = 1.0 [0.8, 1.3] kcal/mol), whereas no clear patterns is observed for GAFF v2.1 (Figure ). Much as seen for the two orientations of the guest molecules within each host, GAFF v2.1 yields relatively large differences in predicted free energies for each guest between the two hosts, but it does not seem to be more accurate for either host relative to the other.