Simulations were performed with the pmemd.cuda module of AMBER 16 (calculations with the GAFF v1.7 force field) and AMBER 18 (calculations with the GAFF v2.1 and SMIRNOFF99Frosst force fields) molecular dynamics software . Each window for each system was independently solvated and simulated. Simulation data for the host-guest complexes using GAFF v1.7 were taken from Henriksen, et al. and are described in additional detail therein. Solvation consisted of 2000 TIP3P waters for the αCD systems and 2210 waters for the βCD systems in an orthorhombic box. The host and guest were oriented via non-interacting dummy atoms along the simulation box's long axis, to allow use of an elongated periodic box that reduces the amount of solvent required for the calculation. Each simulation contained enough Na + or Cl -ions to neutralize the host-guest complex and an additional 50 mM NaCl to match the experimental conditions in . In the GAFF simulations, hydrogen mass repartitioning was used to adjust the mass of hydrogen atoms by a factor of 3 and decreasing the mass of the bound heavy atoms proportionally, keeping the total molecular weight of each molecule constant and enabling a simulation timestep of 4 fs. Hydrogen mass repartitioning produces negligible changes in computed thermodynamic