Figure 2
From: Protoss: a holistic approach to predict tautomers and protonation states in protein-ligand complexes
Three examples for VMRs with alternative modes. Donor surfaces are represented by blue half-circles and acceptor surfaces are represented by red half-circles. In the first two examples, primary alcohol (A) and cyclic secondary amine (B), each mode comprises multiple interaction surfaces for a single atom. In case of the imidazole ring (C) the respective surfaces are associated with different atoms.