First-principles calculations of structural, electronic, and thermodynamic properties of Na(2)BeH(4)

IMR OpenIR

	First-principles calculations of structural, electronic, and thermodynamic properties of Na(2)BeH(4)
	C. H. Hu; Y. M. Wang; D. M. Chen; D. S. Xu; K. Yang
	2007
发表期刊	Physical Review B
ISSN	1098-0121
卷号	76 期号:14
摘要	The plane-wave ultrasoft pseudopotential method based on the density-functional theory has been used to calculate the electronic structures of Na(2)BeH(4). These calculations reveal that at ambient conditions, the crystal structure of alpha-Na(2)BeH(4) at ground state is alpha-K(2)ZnBr(4)-type monoclinic (space group P2(1)/m). With increasing pressure, the structural transition from alpha- to beta-Na(2)BeH(4) (alpha-Cs(2)MgH(4) type, space group Pnma) occurs at 1.1 GPa accompanied with a volume reduction of 8.7%. The density of states and electron localization function analyses show that a stronger covalent-bonding interaction prevails in BeH(4) subunits and the crystals exhibit a nonmetallic feature. The relative thermal stability of alpha- to beta-Na(2)BeH(4) was further investigated by performing phonon calculations based on the density-functional perturbation theory. The calculated Helmholtz free energies and vibrational entropies show that alpha-Na(2)BeH(4) is always kept more stable than beta-Na(2)BeH(4) with increasing temperature and is impossible to be transformed to the beta phase.
部门归属	[hu, c. h.; wang, y. m.] chinese acad sci, inst met res, shenyang natl lab mat sci, shenyang 110016, peoples r china. [hu, c. h.; chen, d. m.; xu, d. s.; yang, k.] chinese acad sci, inst met res, natl engn res ctr, shenyang 110016, peoples r china.;wang, ym (reprint author), chinese acad sci, inst met res, shenyang natl lab mat sci, 72 wenhua rd, shenyang 110016, peoples r china;ymwang@imr.ac.cn
关键词	Reversible Hydrogen Storage X-ray-diffraction Crystal-structure Ultrasoft Pseudopotentials Hydrides Transitions Absorption Tungstate Alanates Solids
URL	查看原文
文献类型	期刊论文
条目标识符	http://ir.imr.ac.cn/handle/321006/33585
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	C. H. Hu,Y. M. Wang,D. M. Chen,et al. First-principles calculations of structural, electronic, and thermodynamic properties of Na(2)BeH(4)[J]. Physical Review B,2007,76(14).
APA	C. H. Hu,Y. M. Wang,D. M. Chen,D. S. Xu,&K. Yang.(2007).First-principles calculations of structural, electronic, and thermodynamic properties of Na(2)BeH(4).Physical Review B,76(14).
MLA	C. H. Hu,et al."First-principles calculations of structural, electronic, and thermodynamic properties of Na(2)BeH(4)".Physical Review B 76.14(2007).