Fig. 2From: Evaluation of the coarse-grained OPEP force field for protein-protein dockingThe OPEP force field. a The potential energy E SS+E SB for side chain–side chain interactions is shown at the energy minimum, which is at σ ij for E SS. For Arg/Asp and Arg/Glu, the average of the two minima for E SB is shown. Repulsive interactions, corresponding to energies higher than zero, are also plotted at σ ij . b The OPEP potential E SS is shown together with the soft function E SS86 for Phe/PheBack to article page