Dependence of the length of the hydrogen bond on the covalent and cationic radii of hydrogen, and additivity of bonding distances

Length of the hydrogen bond in ice (left) and liquid water (right): In ice, d(OH…O) = 2.77 Å and d(-H) = d(H) + d(H+) + d(H) = 1.02 Å. In liquid water, d(OH…O) = 3 Å and d(-H) = d(H) + d (H+) + 2d(H) = 1.39Å