The results of these tests show that both rmax and Lmax have a significative impact on the final accuracy of the trained model. While a value of rmax = 4 Å may intuitively seem large enough to describe the atomic environment around Si and O in a zeolitic framework, we find that larger values of 5 and 6 Å lead to a further improvement of both forces and energies, as shown in Figure . Moreover, by increasing the number of interaction layers in the model from 3 to 5, there is an overall improvement of the performance, while the differences between models obtained with different rmax are decreased.