The selected training set exercises a total of 18 vdW force field parameters (8 hydrogen parameters, 4 carbon parameters and 6 oxygen parameters) all of which were optimized. The training was initially performed using a combination of both molecular simulations and cached simulation data to estimate the data set at each epoch, and then was repeated using only molecular simulation so as to determine what speed up (if any) is provided by the cached data reweighting. A regularized least squares objective function as implemented by the ForceBalance software package was used, where the contribution of the physical properties was computed by: