Both the RF and DNN model can identify polymers with high performance in Datasets C and D. The chemical structures of the selected polymers are drawn in Fig. . We highlight some of the top substructures identified from SHAP analysis (Fig. ) in these chemical structures, which corroborates our earlier conclusions. For instance, the higher permeability polymers tend to have more methyl groups (substructure 2854) and methyl groups attached to aliphatic rings