Phase transition in Ar(H2)2: a prediction of metallic hydrogen organized in lamellar structures
Commissariat à l'Energie Atomique, Centre d'Etudes de Limeil-Valenton, 94195 Villeneuve Saint Georges, France
2 Physique des Milieux Condensés (CNRS URA 782), Boîte 77, Université Paris 6, 4 place Jussieu, 75252 Paris, France
Accepted: 27 January 1997
The structural and electronic properties of the compound are studied as a function of pressure by enthalpy calculations and ab initio molecular dynamics. A phase transition from a to an -type structure is shown to take place around 250 GPa. In the latter structure, the Ar atoms form hexagonal close-packed layers which force the overlap of hydrogen and hence its metallization within experimental reach. Dissociation of molecules is seen to take place gradually, upon increasing pressure.
PACS: 71.30.+h – Metal-insulator transitions and other electronic transitions / 62.50.+p – High-pressure and shock-wave effects in solids and liquids / 71.10.-w – Theories and models of many electron systems
© EDP Sciences, 1997