The Observation of the Oxygen-Oxygen Interactions in Ice - Redefine the term of hydrogen-bonding between water - water molecules

In this article, we present a series of first principle density functional theory simulation results which have, reproduced the vibrational spectra for ice Ih and VIII obtained by neutron scattering. Detailed analysis of the pressure-dependent simulation results shows that there is an Oxygen-Oxygen (O-O) interaction between the nearest water molecules participating in the H-bonding and this interaction is 1.5 times stronger than the H-bond at an O-O distance Roo of 2.7Ã… observed in ice I. The O-O interaction strength increases rapidly to 2.3 times the H-bond at Roo = 2.5 Ã…. Analysis of the simulation results for ice VIII, shows that the strong O-O interaction only exists between H-bonded water molecules (i.e. O-H---O) and not for non-H-bonded water molecules, even when the O---O distances are similar. This discovery completely changed our view of H-bonding in water and ice, incorporation of this term may also help us to explain water anomalies. In addition short H-bonds (Roo <2.7Ã…) exist in DNA and proteins, and are thought to play a role crucial in enzyme catalysis and function. Hence this result could have major implications in our understanding of enzyme-catalysis and biology.