Selected ligands are shown in a) to illustrate the structural diversity. Experimental free energies were obtained from Grädler et al.. The darker and lighter shaded areas show 1 and 2 kcal mol -1 deviations from exact agreement, respectively. Error bars show 95 % confidence intervals, which were assumed to be 0.5 kcal mol -1 for experiment and calculated from the deviation between 5 replicate runs for the predictions. 95 % confidence intervals on statistics were calculated by bootstrapping with 10000 iterations of resampling.