In this study, we report the binding thermodynamics of 43 host-guest complexes (Figure and Table ) computed using three different force fields. The complexes consist of either α-or β-cyclodextrin as host molecules and a series of small molecule guests containing ammonium, carboxylate, or cyclic alcohol functional groups. The cyclodextrins in the current study are cyclic polymers consisting of six (αCD) or seven (βCD) glucose monomers in the shape of a truncated cone. The equilibrium constants and standard molar enthalpies of binding for these 43 complexes have been measured using isothermal titration calorimetry (ITC) at pH = 6.90 and T = 298 K, and nuclear magnetic resonance spectroscopy (NMR) at pH = 7.0 and T = 298 ± 1 K 32 . Calculations on these host-guest systems have been performed previously , and, as in the prior study, we considered only a single stereoisomer for the 1-methylammonium guests because it was not clear whether a mixture or a pure solution was used in Rekharsky, et al. , and the ΔG°d ifference between each stereoisomer is expected to be < 0.1 kcal/mol .