Figs. 2 a and b show a strong correlation between the charges predicted by PiNet-dipole/PiNet2-dipole with the AC model and the charges computed using CM5 population analysis for the QM9 dataset. As demonstrated before, this indicates that the charges from both PiNet-dipole/PiNet2-dipole models have physical meaning because neither models are trained using the CM5 charges as a reference.