For system 4, 25 umbrella windows with a 0.1 nm spacing were used, where the separation was measured as the distance between the COM of heavy atoms of the ligand on the one hand, and the C γ atom of Asp-189 on the other hand. Lastly for system 5, 31 umbrella windows with a 0.1 nm spacing for the first 1.5 nm separation and a 0.2 nm spacing for the next 2.0 nm separation, as suggested in the original research of the system. For the individual umbrella sampling simulations, a harmonic restraining potential was used. For systems 1 and 2, a higher force constant of 10000 kJ/mol/nm 2 was used for the denser windows of the first 1 nm, and a force constant of 1000 kJ/mol/nm 2 for the other windows. For system 3, a force constant of 10000 kJ/mol/nm 2 was used for all US windows.