Quantum-mechanical properties of protons in solid molecular hydrogen at megabar pressures

Citation
S. Tsuneyuki et al., Quantum-mechanical properties of protons in solid molecular hydrogen at megabar pressures, J L TEMP PH, 122(3-4), 2001, pp. 291-296
Citations number
10
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF LOW TEMPERATURE PHYSICS
ISSN journal
0022-2291 → ACNP
Volume
122
Issue
3-4
Year of publication
2001
Pages
291 - 296
Database
ISI
SICI code
0022-2291(200102)122:3-4<291:QPOPIS>2.0.ZU;2-I
Abstract
Quantum distributions of protons in three high-pressure phases of solid mol ecular hydrogen are investigated by the first-principles path integral mole cular dynamics (FP-PIMD) method, in which interatomic forces are calculated precisely based on the density functional theory. The distributions have e ntirely different symmetries from those predicted by conventional simulatio n with classical treatment of protons. Especially in phase II, we found tha t molecular rotation is hindered by quantum fluctuation of protons, having a strong resemblance to a quantum distribution of impurity muonium in cryst alline silicon. The mechanism of this "quantum localization" is clarified b y a detailed study of the potential energy surface for the molecular rotati on.