Figure 2.

Learning curves for C₂ and C₄ molecules. (Left) % mean absolute error of the predicted SA-GPR densities as a function of the number of training molecules. The error normalization is provided by the total number of valence electrons. (Right) root-mean-square errors of the exchange-correlation energies indirectly predicted from the SA-GPR densities and directly predicted via a scalar SOAP kernel, as a function of the number of training molecules. Dashed lines refer to the error carried by the basis set representation.