ESTIMATION OF THE HYDROGEN-BOND LENGTHS TO H3O+ AND H5O2+ IN LIQUID WATER

Hydrogen-bond lengths to protonated water monomer and dimer in liquid water are difficult to estimate from quantum chemistry calculations of protonated water clusters due to cluster size effects. It appears tha t bulk water exhibits shorter hydrogen-bonds as compared with gas-phas e hydrates. Here the empirical Pauling-BEBO relation is used to correl ate the intermolecular O ... H bond length with the intramolecular H-O bond length at a common H-atom. Comparison of the correlation for clu sters and bulk water produces refined estimates for the bond lengths i n question.