First-principles calculations of structural, electronic, and thermodynamic properties of Na(2)BeH(4)
文献类型：期刊论文
| 作者 | C. H. Hu ; Y. M. Wang ; D. M. Chen ; D. S. Xu ; K. Yang |
| 刊名 | Physical Review B
 |
| 出版日期 | 2007 |
| 卷号 | 76期号:14 |
| 关键词 | reversible hydrogen storage x-ray-diffraction crystal-structure ultrasoft pseudopotentials hydrides transitions absorption tungstate alanates solids |
| ISSN号 | 1098-0121 |
| 中文摘要 | 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. |
| 原文出处 | |
| 公开日期 | 2012-04-13 |
| 源URL | [http://ir.imr.ac.cn/handle/321006/33585]  |
| 专题 | 金属研究所_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). |
入库方式： OAI收割
来源：金属研究所
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