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Title: On the mean kinetic energy of the proton in strong hydrogen bonded systems

The mean atomic kinetic energies of the proton, Ke(H), and of the deuteron, Ke(D), were calculated in moderate and strongly hydrogen bonded (HB) systems, such as the ferro-electric crystals of the KDP type (XH{sub 2}PO{sub 4}, X = K, Cs, Rb, Tl), the DKDP (XD{sub 2}PO{sub 4}, X = K, Cs, Rb) type, and the X{sub 3}H(SO{sub 4}){sub 2} superprotonic conductors (X = K, Rb). All calculations utilized the simulated partial phonon density of states, deduced from density functional theory based first-principle calculations and from empirical lattice dynamics simulations in which the Coulomb, short range, covalent, and van der Waals interactions were accounted for. The presently calculated Ke(H) values for the two systems were found to be in excellent agreement with published values obtained by deep inelastic neutron scattering measurements carried out using the VESUVIO instrument of the Rutherford Laboratory, UK. The Ke(H) values of the M{sub 3}H(SO{sub 4}){sub 2} compounds, in which the hydrogen bonds are centro-symmetric, are much lower than those of the KDP type crystals, in direct consistency with the oxygen-oxygen distance R{sub OO}, being a measure of the HB strength.
Authors:
 [1] ;  [2] ; ; ;  [3] ;  [4]
  1. Nuclear Research Center–Negev, Beer-Sheva 84190 (Israel)
  2. Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105 (Israel)
  3. Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)
  4. Institute for Condensed Matter Physics, 1 Svientsitskii str., L’viv 79011 (Ukraine)
Publication Date:
OSTI Identifier:
22493716
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 144; Journal Issue: 5; Other Information: (c) 2016 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CHEMICAL BONDS; COVALENCE; CRYSTALS; DEEP INELASTIC SCATTERING; DENSITY FUNCTIONAL METHOD; DENSITY OF STATES; DEUTERONS; FERROELECTRIC MATERIALS; HYDRIDES; HYDROGEN; KINETIC ENERGY; NEUTRON DIFFRACTION; OXYGEN; PHONONS; POTASSIUM PHOSPHATES; PROTONS; RUBIDIUM SULFATES; SULFATES; VAN DER WAALS FORCES