Both models assign each atom a typed, atom-centered, linear, isotropic polarizability. These empirical atomic polarizabilities are derived from electrostatic potential responses when an imposed external electric field is present. This method has been widely employed in different flavors of induced dipole model, some examples are included in references. In one model, partial charges are assigned with RESP 5 -type fitting to QM ESPs in the context of the typed polarizabilities. In the second model, the AM1-BCC 6,7 method is used, but with a new set of BCCs trained to replicate QM ESPs in the context of our typed polarizabilities.