Figure 3

Illustration of the lack of agreement between the IIT⁴⁷ and SSUB⁴⁶ experimental thermochemical databases. Plots average error ($\Delta H_{\mathrm{f}}^{\text{SSUB}-\text{IIT}}$) against IIT formation energy ($\Delta H_{\mathrm{f}}^{\mathrm{IIT}}$), with the distribution of errors summarised in the histogram at the bottom. The significant range of $\Delta H_{\mathrm{f}}^{\mathrm{IIT}}$ values demonstrates the surprising degree of disagreement between these experimental formation energy databases. This experiment to experiment comparison for the 75 intermetallic compounds common to both databases gives a MAE of 0.082 eV/atom, whereas the MAE of OQMD formation energies for intermetallic compounds is 0.071 eV/atom (using ‘fit-none’ chemical potentials).