Quantum behavior of water nano-confined in beryl

Y Finkelstein; R Moreh; S L Shang; Y Wang; Z K Liu

doi:10.1063/1.4978397

Quantum behavior of water nano-confined in beryl

J Chem Phys. 2017 Mar 28;146(12):124307. doi: 10.1063/1.4978397.

Authors

Y Finkelstein¹, R Moreh², S L Shang³, Y Wang³, Z K Liu³

Affiliations

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, USA.

PMID: 28388143
DOI: 10.1063/1.4978397

Abstract

The proton mean kinetic energy, Ke(H), of water confined in nanocavities of beryl (Be₃Al₂Si₆O₁₈) at 5 K was obtained by simulating the partial vibrational density of states from density functional theory based first-principles calculations. The result, Ke(H) = 104.4 meV, is in remarkable agreement with the 5 K deep inelastic neutron scattering (DINS) measured value of 105 meV. This is in fact the first successful calculation that reproduces an anomalous DINS value regarding Ke(H) in nano-confined water. The calculation indicates that the vibrational states of the proton of the nano-confined water molecule distribute much differently than in ordinary H₂O phases, most probably due to coupling with lattice modes of the hosting beryl nano-cage. These findings may be viewed as a promising step towards the resolution of the DINS controversial measurements on other H₂O nano-confining systems, e.g., H₂O confined in single and double walled carbon nanotubes.