Figure depicts the correlation of Mulliken and kQEq charges for all atoms in the test set. While there is a moderate overall correlation between the charges, there are also clear differences. In particular, we see two general trends. First, kQEq charges appear in a broader range (-1 to 2.5) while Mulliken charges lie between -0.5 and 0.5. Second, kQEq charges display a much more pronounced clustering into functional groups. This is particularly evident for oxygen. While the Mulliken analysis assigns similar charges to ether and carbonyl oxygen atoms, kQEq predicts the carbonyl groups to be significantly more polar. Similarly, the polarity of nitrile and fluoride functional groups is much higher in kQEq.