Visualization of interaction energy terms. Electrostatic (A, B) and van der Waals (C, D) interaction values between a receptor model and one of the compounds in the training set were mapped onto the receptor binding site surface (in red stabilizing and in blue destabilizing regions for complex formation). The upper panel (A, C) shows the unweighted interaction energy terms and the lower panel (B, D) the corresponding ones, weighted by the COMBINE model. It can be seen that not all of the interaction energies have the same impact on the binding affinity.