The > 98% accuracy on splits (iv) and (v) demonstrates the ability of the models to extrapolate to longer alkanes. The > 90% accuracy on splits (ii) and (iii) shows that while not as good as extrapolating on length, the models perform reasonably well when extrapolating to highly branched alkanes. Chemprop performs better than the fingerprint-based MLP model in most of cases, which is reasonable given that a message-passing architecture is more complex than the MLP fingerprints.