(13a) through Eq. (13f) as well as for the hyperparameters which rescale the errors for each experimental dataset. In Fig. 4, we plot the model predictions for each phase versus temperature for the results of two previous assessments and the datasets used. The first assessment is from Arblaster [17], hereafter Arb2014, whose results leverage their knowledge and expertise to judge the quality of various experimental measurements and come up with a final model. The second assessment was performed using thermodynamic information and HSC Chemistry, a software package which automatically combines existing thermodynamic assessments to find an optimal model, leveraging multiple experts whenever possible. The software uses **data** from literature, especially review articles. Whenever possible, we trace back the original article and use the   content correction). This explains why the two beta-phase models follow the same trend in enthalpy but are highly discrepant in specific heat. Furthermore, the linear model of Arb2014 for enthalpy forces the specific heat to be constant and to take a value which does not pass through the majority of the experimental specific heat measurements. The difference between our model and the HSC chemistry assessment is small, as the HSC Chemistry software appears to have incorporated specific heat measurements. Uncertainty intervals are broader for the beta-phase model due to the fewer number of **data** points and their significant spread.