https://doi.org/10.1140/epjb/e2015-60042-5
Regular Article
Ab initio study of structural and mechanical property of solid molecular hydrogens
1
School of Physical Electronics, University of Electronic Science
and Technology of China, Chengdu
610054, P.R.
China
2
Institute of Nuclear Physics and Chemistry, China Academy of
Engineering Physics, Mianyang
621900, P.R.
China
3
Department of Materials Science and Engineering, University of
North Texas, Denton,
TX
76203,
USA
a
e-mail: yanglildk@uestc.edu.cn
Received: 14 January 2015
Received in final form: 18 April 2015
Published online: 22 June 2015
Ab initio calculations based on density functional theory (DFT) were performed to investigate the structural and the elastic properties of solid molecular hydrogens (H2). The influence of molecular axes of H2 on structural relative stabilities of hexagonal close-packed (hcp) and face-centered cubic (fcc) structured hydrogen molecular crystals were systematically investigated. Our results indicate that for hcp structures, disordered hydrogen molecule structure is more stable, while for fcc structures, Pa3 hydrogen molecular crystal is most stable. The cohesive energy of fcc H2 crystal was found to be lower than hcp. The mechanical properties of fcc and hcp hydrogen molecular crystals were obtained, with results consistent with previous theoretical calculations. In addition, the effects of zero point energy (ZPE) and van der Waals (vdW) correction on the cohesive energy and the stability of hydrogen molecular crystals were systematically studied and discussed.
Key words: Solid State and Materials
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2015
