Abstract
Three-dimensionally resolved proton momentum distributions and end-to-end distributions have been calculated for hexagonal and cubic water ice. First-principles quantum nuclear wave functions have been used to investigate the impact of vibrational anisotropy, anharmonicity, proton and stacking disorder, temperature, and pressure on these distributions. Moreover, the effects of vibrations on the electronic density in hexagonal ice are shown to lead to a 5% vibrational correction with respect to the static-lattice optical permittivity, and proton disorder is found to be crucial in explaining its experimentally observed temperature dependence.
Highlights
Hydrogen-bonded materials play an important role across many fields of science
Measurements of the spatially resolved momentum distribution in KH2PO4 [37], which in its crystalline form is used in optical modulators and for nonlinear optics such as second-harmonic generation, and Rb3H(SO4)2 [38] suggest that ni(p) in Ih should become accessible in the future with improved experimental techniques
Unlike temperature and pressure, substantially affects the proton position and momentum distributions in Ih. It is crucial for the temperature dependence of the permittivity of Ih
Summary
Hydrogen-bonded materials play an important role across many fields of science. Anharmonicity plays an important role in the anomalous thermal expansion of ice Ih [8], in proton and deuteron isotopic effects [9,10,11], and in shifts in infrared and other vibrational spectra [7]. Quantum zero-point (ZP) and thermal motion of the protons have a large impact on the electronic properties of ice [12,13]. We study the effects of vibrational motion on the electronic density and permittivity of ice using first-principles density-functional-theory (DFT) methods. We have compared the results of our firstprinciples calculations of position and momentum distributions with experimental data, which provides a stringent test of computational descriptions of ice and the hydrogen bond
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
