where X ij is the centroid between O i and O j . The angles θ ij and ϕ ij are shown pictorially in Figure . Based on the TS structures found, we can roughly characterize a pocket as "small" if θ < 105 ○ -110 ○ and ϕ < 125 ○ and "large" otherwise. The values of the χ i , θ ij and ϕ ij angles for all 11 sites are reported in Tables S1 of the SI.