The simulations were run using a Langevin thermostat at a constant temperature of 298.15 K and a collision frequency of 1.0 ps 1, using a Monte Carlo barostat with a constant pressure of 1 atm. Host-guest systems were minimized up to a maximum of 5000 steps and equilibrated in the NPT ensemble for 1 ns. Production simulations were also run in the NPT ensemble for up to 50 ns per window. The non-bonded interaction were truncated with a 9.0 Å cutoff. The long-range electrostatic interactions were handled with the particle mesh Ewald (PME) method , and the long-range van der Waals interactions were treated with an isotropic dispersion correction. Simulation time steps were set to 4 fs with Hydrogen Mass Repartitioning (HMR). The binding free energy quantities were estimated with thermodynamic integration (TI) and/or Multistate Bennett Acceptance Ratio (MBAR) method. Uncertainties for the TI estimates were calculated using block analysis as described in the literature. However, for reference submissions only the estimates with MBAR were included.