Figure shows the results of re-optimizing the parameters after adding QM training data calculated at energy-minimized structures using the optimized force field. The initial energies predicted in the first cycle have a RMSE of 9.08 kcal/mol, with the force field predicting MM energies that are too low compared to the QM data. The addition of these data points to the objective function in Equation 3 seeks to increase the energies of these spurious minima.