Phonon spectrum and density of states for commensurate monolayer phases of H2, HD, and D2 on graphite

A self-consistent-phonon approximation was used to calculate the ground-state properties and phonon density of states for the square-root 3 x square-root 3 R 30-degrees commensurate phase of monolayer H-2, HD, and D2 adsorbed on graphite. The adsorbed molecules were assumed to be in a pure J=0 rotational state, and the wave function for the solid included coordinates both parallel and perpendicular to the surface. The proper inclusion of the surface-normal terms in the wave function was found to have a significant effect on both the phonon spectrum and the ground-state properties. The calculations for the ground-state energy and the phonon spectrum of these solids were done both with and without the inclusion of short-range correlations, these short-range correlations being treated within a version of the T-matrix approximation. The possible effects of various substrate-mediated interactions, anisotropic admolecule-carbon interactions, and finite temperatures were also investigated. The current theoretical results are compared to those of recent inelastic-neutron-scattering experiments and to previous theoretical results for these systems.

Title	Phonon spectrum and density of states for commensurate monolayer phases of H2, HD, and D2 on graphite
Creator	Novaco, Anthony D.
Publisher	Physical Review B
Academic Department	Physics
Division	Natural Sciences
Organization	Lafayette College
Date Issued	October 1, 1992
Date Available	2011-03-14T14:13:01Z
Type	Article
Language	English
Bibliographic Citation	Novaco, A. D. (1992). "Phonon spectrum and density of states for commensurate monolayer phases of H2, HD, and D2 on graphite." Physical Review B 46 (13): 8178-8194.
Standard Identifier	Handle 10385/811
Permalink	http://hdl.handle.net/10385/811
Rights Statement	In Copyright
Rights Holders	The American Physical Society