A combined INS and DINS study of proton quantum dynamics of ice and water across the triple point and in the supercritical phase

作者：Andreani C; Romanelli G^*; Senesi R

来源：Chemical Physics, 2013, 427: 106-110.

DOI：10.1016/j.chemphys.2013.07.009

• Hydrogen bond
• Proton potential
• Inelastic Neutron Scattering

We report new results of a combined analysis of previous Inelastic Neutron Scattering (INS) and Deep Inelastic Neutron Scattering (DINS) experiments on ice at T = 271 K and water at T = 285 K and T = 673 K. Proton quantum dynamics is discussed in terms of the total mean kinetic energy, %26lt; E-K %26gt;, and its three principal direction components, %26lt; E-K %26gt;(alpha) (with alpha - x, y, z), the lineshape momentum distribution, n(p), and its harmonic lineshape components, n(h)(p). The results show that the single proton dynamics is ground-state dominated and that %26lt; E-K %26gt;(x); %26lt; E-K %26gt;(y) and %26lt; E-K %26gt;(z) consist mainly of weighted averages of a mix of bending and librational, librational and stretching mean kinetic energy components, respectively. The stretching component %26lt; E-K %26gt;(z) is redshifted respect to its harmonic component due to additional network mode contributions and softening caused by anharmonicity. The n(p) lineshapes derived at the investigated temperature reflect the anisotropy and quasi-harmonic nature of proton motion in ice and water.

• 出版日期2013-12-12