We began by constructing an additive polarizability model as a baseline comparison for GFN2/D4 performance. For this model, each atom in a molecule was assigned its GAFF atom type, which was used to further assign it to an Alexandria polarizability type and then finally a corresponding atomic polarizability. The molecular polarizability was calculated as the simple sum of these atomic polarizabilities. We found that the additive model performed extremely similarly to GFN2/D4 (Figure ), providing computed polarizabilities with high correlation with GFN2/D4 (Figure ).