Fig. 1.

Learning curves for the per atom polarizabilities of the molecules in the QM7b database calculated using either CCSD or DFT as well as for the difference ($\mathrm{\Delta }$) between the two. The testing set consists of 1,811 molecules, and the right-hand axis shows the RMSE as a fraction of the intrinsic variability of the CCSD polarizability, ${\sigma }_{\text{CCSD}}$.