La double identité de la forme X de la glace.

The double identity of ice X.

Type d'article : Article

Résumé

The new computer simulation of molecular dynamics, using path integral methods that treat the particles quantum mechanically, clearly establishes the existence of this new form of ice. Benoit et al. change the distance between two oxygen atoms continuously from 0.26 to 0.22 nanometres, which corresponds to an applied pressure of more than 140 gigapascals. By the end, the authors have ice X, and the proton is symmetrically placed between the oxygen atoms. The surprise comes at intermediate pressures. There is, first, a transition to paraelectric ice VII. At somewhat higher pressure it becomes centred midway along the O-O line due to zero point motion: quantum mechanics produces a symmetric form of ice earlier than expected, a different type of ice X.

Détails

Titre original : The double identity of ice X.
Identifiant de la fiche : 1999-0709
Langues : Anglais
Source : Nature - vol. 392 - n. 6673
Date d'édition : 19/03/1998
Document disponible en consultation à la bibliothèque du siège de l'IIF uniquement.

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Indexation

Thèmes : Thermodynamique et changement d’état
Mots-clés : Glace; Atome; Propriété physique; Simulation; Molécule; Haute pression