First-principles calculations of structural, electronic, and thermodynamic properties of Na2BeH4

doi:10.1103/PhysRevB.76.144104

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	First-principles calculations of structural, electronic, and thermodynamic properties of Na2BeH4
	Hu, C. H.1,2; Wang, Y. M.1; Chen, D. M.2; Xu, D. S.2; Yang, K.2
刊名	PHYSICAL REVIEW B
	2007-10-01
卷号	76 期号:14 页码:7
ISSN号	1098-0121
DOI	10.1103/PhysRevB.76.144104
通讯作者	Wang, Y. M.(ymwang@imr.ac.cn)
英文摘要	The plane-wave ultrasoft pseudopotential method based on the density-functional theory has been used to calculate the electronic structures of Na2BeH4. These calculations reveal that at ambient conditions, the crystal structure of alpha-Na2BeH4 at ground state is alpha-K2ZnBr4-type monoclinic (space group P2(1)/m). With increasing pressure, the structural transition from alpha- to beta-Na2BeH4 (alpha-Cs2MgH4 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 BeH4 subunits and the crystals exhibit a nonmetallic feature. The relative thermal stability of alpha- to beta-Na2BeH4 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-Na2BeH4 is always kept more stable than beta-Na2BeH4 with increasing temperature and is impossible to be transformed to the beta phase.
WOS研究方向	Physics
语种	英语
出版者	AMER PHYSICAL SOC
WOS记录号	WOS:000250620300024
内容类型	期刊论文
源URL	[http://ir.imr.ac.cn/handle/321006/91016]
专题	金属研究所_中国科学院金属研究所
通讯作者	Wang, Y. M.
作者单位	1.Chinese Acad Sci, Inst Met Res, Shenyang Natl Lab Mat Sci, Shenyang 110016, Peoples R China 2.Chinese Acad Sci, Inst Met Res, Natl Engn Res Ctr, Shenyang 110016, Peoples R China
推荐引用方式 GB/T 7714	Hu, C. H.,Wang, Y. M.,Chen, D. M.,et al. First-principles calculations of structural, electronic, and thermodynamic properties of Na2BeH4[J]. PHYSICAL REVIEW B,2007,76(14):7.
APA	Hu, C. H.,Wang, Y. M.,Chen, D. M.,Xu, D. S.,&Yang, K..(2007).First-principles calculations of structural, electronic, and thermodynamic properties of Na2BeH4.PHYSICAL REVIEW B,76(14),7.
MLA	Hu, C. H.,et al."First-principles calculations of structural, electronic, and thermodynamic properties of Na2BeH4".PHYSICAL REVIEW B 76.14(2007):7.