Theory of high pressure hydrogen, made simple

Abstract

Phase I of hydrogen has several peculiarities. Despite having a close-packed crystal structure, it is less dense than either the low temperature Phase II or the liquid phase. At high pressure, it transforms into either phase III or IV, depending on the temperature. Moreover, spectroscopy suggests that the quantum rotor behaviour disappears with pressurisation, without any apparent phase transition. Here we present a simple thermodynamic model for this behaviour based on packing atoms and molecules and discuss the thermodynamics of the phase boundaries. We also report first principles molecular dynamics calculations for a more detailed look at the same phase transitions.

References in corpus (7)

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• Generalized gradient approximation for solids and their surfaces
• Density functional theory study of phase IV of solid hydrogen
• Dissociation of high-pressure solid molecular hydrogen: Quantum Monte Carlo and anharmonic vibrational study
• Fate of density functional theory in high-pressure solid hydrogen
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Cited by in corpus (9)

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• The role of van der Waals and exchange interactions in high-pressure solid hydrogen
• A simple thermodynamic model for the hydrogen phase diagram
• Infrared Peak-Splitting from phonon localization in Solid Hydrogen
• Understanding high pressure hydrogen with a hierarchical machine-learned potential
• Structures of solid hydrogen at 300K
• Prediction of a Mobile Solid State in Dense Hydrogen under High Pressures
• Isotope quantum effects in the metallization transition in liquid hydrogen
• The Icosahedral (H${}_2{)}_{13}$ Supermolecule