Extrapolating the power law scaling evident in these curves, we estimate that increasing training As an estimate of the number of outliers, there are a total of 796 testing samples (out of 12,139 total, or ∼ 7%) with absolute errors greater than 10.2 kcal/mol (3x the standard deviation as estimated from the median absolute deviation). Based on the testing set size and assuming normal statistics only ∼ 14 samples (i.e., ∼0.1% of the testing split) would be expected with errors this large. An analogous calculation using the absolute percent errors rather than the absolute errors produces a large number of percentage based outliers that is driven mainly by low barrier reactions and not necessarily unphysical predictions (Fig. ), and these are not further analyzed here.