Strong Isotope Effect in Phase II of Dense Solid Hydrogen and Deuterium
Abstract
Quantum nuclear zero-point motions in solid H2 and D2 under pressure are investigated at 80 K up to 160 GPa by first-principles path-integral molecular dynamics calculations. Molecular orientations are well defined in phase II of D2, while solid H2 exhibits large and very asymmetric angular quantum fluctuations in this phase, with possible rotation in the (bc) plane, making it difficult to associate a well-identified single classical structure. The mechanism for the transition to phase III is also described. Existing structural data support this microscopic interpretation.
- Publication:
-
Physical Review Letters
- Pub Date:
- October 2012
- DOI:
- 10.1103/PhysRevLett.109.155303
- arXiv:
- arXiv:1205.2290
- Bibcode:
- 2012PhRvL.109o5303G
- Keywords:
-
- 67.80.ff;
- 62.50.-p;
- Molecular hydrogen and isotopes;
- High-pressure effects in solids and liquids;
- Condensed Matter - Materials Science
- E-Print:
- 5 pages, 3 figures