The cyclodextrin challenge proved to be the least challenging of the SAMPL7 challenges as measured by RMS error, as all submissions except one had RMSE values less than 2.74 kcal/mol (the exception was the AM1-BCC/MD/GAFF/TIP4PEW/QMMM method, with RMSE and ME metrics over 30 kcal/mol). However, the dynamic range was particularly small for this challenge, with most host-guest complexes showing similar binding free energies. This meant that correlations between calculated and predicted values were typically quite poor (Table ).