It can also be useful to assess the fitting of individual parameters. To do this for a given bond-stretch parameter, for example, we collected all test cases that included the parameter of interest and made a scatter plot of the length of the bond in the QM geometries vs the length in the MM geometries. Such plots were generated for each bond-length, bond-angle, and improper dihedral, in the training set, and all are available in the release package. When considering this term by term analysis, it should be kept in mind that the length of a bond or the value of an angle in an optimized geometry is determined not just by the parameters of the corresponding force field term, but also by the rest of the structure. For example, a bond length may be shifted by ring strain. However, when these values consistently differ between QM and MM geometries, this can be an indicator that the specific force field parameter requires further attention.