Proton dynamics in high-pressure ice-VII from density functional theory

TL;DR

This study uses density functional theory to investigate proton movement in high-pressure ice-VII, revealing a continuous transition in proton potential and dynamics consistent with recent NMR experimental findings.

Contribution

It provides a detailed theoretical analysis of proton symmetrization and dynamics in ice-VII under high pressure, aligning with experimental observations.

Findings

Proton potential transitions from double- to single-well with increasing pressure.

Proton dynamics are significant in the pressure range of 20-95 GPa.

Theoretical results agree with recent NMR experiments.

Abstract

Using a density-functional-theory-based approach, we explore the symmetrization and proton dynamics in ice-VII, for which recent high-pressure NMR experiments indicate significant proton dynamics in the pressure-range of $20-95$ GPa. We directly sample the potential seen by the proton and find a continuous transition from double- to single-well character over the pressure range of 2 to 130 GPa accompanied by proton dynamics in agreement with the NMR experiments.