Figure shows the absolute error distribution grouped by chemical family. A similar standard deviation of 0.25 eV is found for each of the families (Table ). Lower errors are retrieved for C x H y O (2,3) (0.13 eV), amides (0.15 eV), oximes (0.19 eV) and carbamates (0.16 eV). Larger errors are associated to the aromatic compounds, with a standard deviation of 0.48 eV.