From the docked ligands, a perturbation map was constructed to identify suitable edges based on maximum common substructure matching. This functionality is available in Icolos using either Schrodinger's fep_mapper.py script or LOMAP . In this work, a single perturbation map was generated for each test system using Schrodinger's fep_mapper.py script and the Glide MCS poses to eliminate the effect of changes to the perturbation map topology on the accuracy of RBFE predictions.