Isotopic differentiation and sublattice melting in dense dynamic ice

Andreas Hermann*, N. W. Ashcroft, Roald Hoffmann

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

The isotopes of hydrogen provide a unique exploratory laboratory for examining the role of zero point energy (ZPE) in determining the structural and dynamic features of the crystalline ices of water. There are two critical regions of high pressure: (i) near 1 TPa and (ii) near the predicted onset of metallization at around 5 TPa. At the lower pressure of the two, we see the expected small isotopic effects on phase transitions. Near metallization, however, the effects are much greater, leading to a situation where tritiated ice could skip almost entirely a phase available to the other isotopomers. For the higher pressure ices, we investigate in some detail the enthalpics of a dynamic proton sublattice, with the corresponding structures being quite ionic. The resistance toward diffusion of single protons in the ground state structures of high-pressure H2O is found to be large, in fact to the point that the ZPE reservoir cannot overcome these. However, the barriers toward a three-dimensional coherent or concerted motion of protons can be much lower, and the ensuing consequences are explored.

Original languageEnglish
Article number214113
Number of pages8
JournalPhysical review B
Issue number21
Publication statusPublished - 27 Dec 2013

Keywords / Materials (for Non-textual outputs)

  • SOLID HE-4
  • NEON


Dive into the research topics of 'Isotopic differentiation and sublattice melting in dense dynamic ice'. Together they form a unique fingerprint.

Cite this