J. Phys. Chem. B DOI: 10.1021/jp407836n

http://pubs.acs.org/doi/abs/10.1021/jp407836n

Abstract

Acombination of the Lagrangian mechanics of oscillators vibration, moleculardynamics decomposition of volume evolution, and Raman spectroscopy of phononrelaxation has enabled us to resolve the asymmetric, local, and short-range potentialspertaining to the hydrogen bond (O:H-O) in compressed ice. Results show thatboth oxygen atoms in the O:H-O bond shift initially outwardly with respect tothe coordination origin (H), lengthening the O—O distance by 0.0136 nmfrom 0.2597to 0.2733 nm by Coulomb repulsion between electron pairs on adjacentoxygen atoms. Both oxygen atoms then move toward right along the O:H-O bond bydifferent amounts upon being compressed, approaching identical length of 0.11nm. The van der Waals potential V_L(r) for the O:H noncovalent bond reachesa valley at -0.25 eV, and the lowest exchange V_H(r) for the H-O polar-covalentbond is valued at -3.97 eV.