Configurations were collected every 100 fs, yielding a total of 40,000 configurations. At these configurations the energy and gradient were computed at the B3LYP/cc-pVDZ level of theory. Thus, only a small fraction, 1 percent, of the MM3 configurations were used to obtain the DFT energies and forces. The energies and forces were obtained using the Gaussian 16 computational chemistry package. In a second scheme, configurations from the 500 K direct dynamics were obtained as follows.