As noted previously, we bias our move proposals towards "large" rotations to ensure that NCMC is efficiently enhancing sampling alternate rotamer states; NCMC rotational moves are only proposed to a rotameric state that differs from the starting state, as shown in Figure . For example, in the case of valine, a rotamer in the trans (χ 1 ≈ 180 • ) state will be limited to move proposals that would result in it occupying either the gauche(-