Ab initio study of structural and mechanical property of solid molecular hydrogens

• Published in: The European physical journal. B, Condensed matter physics Condensed matter physics, 2015-06, Vol.88 (6), Article 161
• Main Authors: Ye, Yingting, Yang, Li, Yang, Tianle, Nie, Jinlan, Peng, Shuming, Long, Xinggui, Zu, Xiaotao, Du, Jincheng
• Format: Article
• Language: English
• Subjects: Complex Systems; Condensed Matter Physics; Density functionals; Fluid- and Aerodynamics; Hydrogen; Mechanical properties; Pellet fusion; Physics; Physics and Astronomy; Regular Article; Solid State Physics
• ISSN: 1434-6028; 1434-6036
• DOI: 10.1140/epjb/e2015-60042-5

Ab initio calculations based on density functional theory (DFT) were performed to investigate the structural and the elastic properties of solid molecular hydrogens (H 2 ). The influence of molecular axes of H 2 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 H 2 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.