Figure 8:

The bootstrapped uncertainty in the solvation free energy estimate with three-stage MBAR are lowest when all QM/MM re-evaluations are done only at the physical MM end states where the overlap to the QM states is highest. The uncertainties increase when re-evaluated samples are moved away from the physical MM end states. The increase is most pronounced for solvent phase methanol, because only the physical MM end state has high overlap to the QM/MM state. A total of 15,000 samples are taken evenly from each reweighted intermediate state and the uncertainties as a function of the number of reweighted states are shown for A) gas phase ethane, B) gas phase methanol, C) solvent phase ethane, and D) solvent phase methanol.