The "pure only" training set is composed of one and one Δ measurement for each of the selected molecules (Figure ). These molecules were manually chosen to include a selection of esters, ethers, ke-tones, alcohols and alkanes which included long/short chain, branched/unbranched, and cyclic/acyclic characteristics, where data was available. The measurements were sourced from the NIST ThermoML archive. The Δ measurements were sourced directly from the literature, as very limited data for the moieties of interest is available in the ThermoML Archive. Many data points were curated from the Majer et al. review , where care was taken to select data points which were deemed as reliable by the authors, and for which at least three independent measurements had been made and were in reasonable agreement. In total, 28 molecules were chosen for a total of 56 data points (28 data points and 28