Proton Transfer in Phase IV of Solid Hydrogen and Deuterium

Abstract

The recent discovery of phase IV of solid hydrogen and deuterium consisting of two alternate layers of graphenelike three-molecule rings and unbound H2 molecules have generated great interests. However, vibrational nature of phase IV remains poorly understood. Here, we report a peculiar proton transfer and a simultaneous rotation of three molecule rings in graphenelike layers predicted by ab initio variable cell molecular dynamics simulations for phase IV of solid hydrogen and deuterium at pressure ranges of from 250 to 350 GPa and temperature range of from 300 to 500 K. This proton transfer is intimately related to the particular elongation of molecules in graphenelike layers, and it becomes more pronounced with increasing pressure at the course of larger elongation of molecules. As the consequence of proton transfer, hydrogen molecules in graphenelike layers are short lived and hydrogen vibration is strongly anharmonic. Our findings provide direct explanations on the observed abrupt increase of Raman width at the formation of phase IV and its large increase with pressure.

4 pages and 4 figures

References in corpus (6)

• Nuclear quantum effects in solids using a colored-noise thermostat
• Density functional theory study of phase IV of solid hydrogen
• Metric-tensor flexible-cell algorithm for isothermal-isobaric molecular dynamics simulations
• Room-Temperature Structures of Solid Hydrogen at High Pressures
• Bonding, structures, and band gap closure of hydrogen at high pressures
• Nuclear quantum effects in ab initio dynamics: theory and experiments for lithium imide

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• Coupled Electron-Ion Monte Carlo simulation of hydrogen molecular crystals
• The role of van der Waals and exchange interactions in high-pressure solid hydrogen
• New Phases and Dissociation-Recombination of Hydrogen Deuteride to 3.4 Megabar
• Anhamonic finite temperature effects on the Raman and Infrared spectra to determine the crystal structure phase III of solid molecular hydrogen
• Prediction of a Mobile Solid State in Dense Hydrogen under High Pressures
• Appraisal of the realistic accuracy of Molecular dynamics of high pressure hydrogen
• Theory of high pressure hydrogen, made simple
• Intermolecular coupling and fluxional behavior of hydrogen in phase IV
• Efficacious calculation of Raman spectra in high pressure hydrogen
• High Temperature Raman analysis of Hydrogen Phase IV from Molecular Dynamics
• Experimental phase transition mapping for hydrogen above 300 K up to 300 GPa