FIGURE 6.

Combined potential using sections from both forward and backward pulling directions. The combined PMF along the proposed pathway, including error bars, is shown in black. The error bars are calculated from the different sections, representing the statistical error for estimating the free-energy change from a work distribution with the second-order cumulant expansion using only 10 trajectories to describe the work distribution. Data from both pulling directions are combined to give the minimum statistical error along the PMF. Since start and endpoint of the potential are fixed (see text), the error decreases from its maximum in the midregion of the potential in both directions. Compared to the total modulation depth of the potential, the error is on average ∼25% and the maximum error is ∼50%.