For the computation of the free energy profile associated with the glycosidic linkages and the Cremer and Pople θ pucker angle, bin sizes of 8° and 6° were used, respectively. Errors in the reweighted estimates of the φψ free energy surfaces were obtained by bootstrap resampling the surfaces 25000 times and calculating the standard deviation in the bin estimates across all bootstrap samples. In order to further analyze the conformational diversity of the Lewis oligosaccharides, the unbiased and msesMD trajectories of systems a-d (Figure ) were clustered based on the RMS distance of core Gal-GlcNAc-Fuc ring atoms using the DBSCAN algorithm using an ε distance cutoff of 0.1725 Å 2 and minimum criteria of four frames to create a cluster.