title: Potential of hydrogen bond in water. Comparison of the theory with vibrational spectra and results of molecular dynamics simulations.
abstract: Potential of hydrogen bond is the function which relates its energy to geometrical parameters of hydrogen bridge: its length R(O…O) and angles between direction O…O and OH group [φ (H-O…O)] and/or lone pair of proton accepting oxygen atom [χ(-O…O)]. Previously we have suggested an approach to design such potentials based on the approximate numerical solution of a reverse problem of the spectrum band shape in the frames of the fluctuation theory of hydrogen bonding. In the given work this method is applied to construction of the two-parameter potentials that depend on parameters {R(O…O), φ (H-O…O} or {φ (H-O…O), χ (-O…O)}. Using them, the spectra of OH vibrations of HOD molecules in a liquid phase are calculated theoretically in good agreement with experiment in the temperature range up to 200 °C. Distributions of angles P(φ, T), P(χ, T), and energies P(E) are calculated also. The same distributions and spectra are independently calculated on the basis of the geometrical parameters of the hydrogen bridges obtained from molecular dynamics models of water. The shapes of the spectral contours and their temperature evolution calculated for computer models turned out to be similar to experimental ones only for the potential that includes the length of H-bond R(O…O).
authors.affiliation: Institute of Chemical Kinetics & Combustion, Siberian Branch of the Russian Academy of Sciences, Novosibirsk 630090, Russia. efimov@kinetics.nsc.ru
authors.forename: Yuri Ya
authors.initials: YY
authors.lastname: Efimov
authors.forename: Yuri I
authors.initials: YI
authors.lastname: Naberukhin
mesh_terms: D006860:Hydrogen Bonding; D017665:Hydroxyl Radical; D056004:Molecular Dynamics Simulation; D013059:Spectrum Analysis, Raman; D013816:Thermodynamics; D014732:Vibration; D014867:Water / Q000737:chemistry*
chemical_list: D014867:Water; D017665:Hydroxyl Radical