A Monte Carlo study of the rotation-libration transition in solid H2under pressure

✍ Scribed by I. Aviram; S. Goshen; R. Thieberger

• Publisher: Springer US
• Year: 1980
• Tongue: English
• Weight: 339 KB
• Volume: 38
• Category: Article
• ISSN: 0022-2291
• DOI: 10.1007/bf00114332

✦ Synopsis

The pressure-induced transition in solid para-H2 from free rotation of molecules to libration around the threefold axes of the fcc structure is calculated using an anisotropic potential including quadrupole-quadrupole and repulsive valence interactions. The rotational part of the Hamiltonian is assumed to be operating on a Yastrow-type wave function, including two variational parameters. Two forms of pair correlation functions are examined, while the variational integrals are evaluated by a Monte Carlo procedure. The results are: (a) no significant correlation effects are detected; (b) the transition density corresponds to R/Ro = 0.676, where Ro is the nearest neighbor separation at zero pressure; the transition is first order as obtained also in mean field calculations; (c ) the order parameter at the transition is O. 09, as opposed to O. 17in mean field; (d) the transition density is not very sensitive to variations in the interaction strength.