First-principles study of the electronic structure of a superstoichiometric rare earth dihydride Gd H2.25
来源期刊：Journal of Rare Earths2016年第1期
论文作者：Z.Ayat A.Boukraa B.Daoudi
文章页码：66 - 70
摘 要：We performed ab initio calculations of electronic structure and equilibrium properties for the rare earth superstoichiometric dihydride Gd H2.25（with the space group Pm-3m（No. 221）） using the full-potential linearized augmented plane wave method（FP-LAPW） approach within the density functional theory（DFT） in the generalized gradient approximation（GGA） and local density approximation（LDA） as implemented in the WIEN2 k simulation code at 0 K. The equilibrium properties were determined, the density of states, electronic density and the energy band structures were studied in details. It was concluded that the GGA optimized lattice parameter agreed much better with the experimental findings than the LDA one. The non negligible electronic density of states at the Fermi level confirmed that the Gd H2.25 had a metallic character. The Fermi energy EF fell at a level where most of the states were rare-earth 5d-eg conduction states while negligible contributions of both interstitial（tetrahedral and octahedral） H s-states were observed near EF. From electronic density, the bonding between Gd and tetrahedral H atoms was of prominent covalency, while was ionic between Gd and octahedral H atoms.
Z.Ayat，A.Boukraa，B.Daoudi
摘 要：We performed ab initio calculations of electronic structure and equilibrium properties for the rare earth superstoichiometric dihydride Gd H2.25（with the space group Pm-3m（No. 221）） using the full-potential linearized augmented plane wave method（FP-LAPW） approach within the density functional theory（DFT） in the generalized gradient approximation（GGA） and local density approximation（LDA） as implemented in the WIEN2 k simulation code at 0 K. The equilibrium properties were determined, the density of states, electronic density and the energy band structures were studied in details. It was concluded that the GGA optimized lattice parameter agreed much better with the experimental findings than the LDA one. The non negligible electronic density of states at the Fermi level confirmed that the Gd H2.25 had a metallic character. The Fermi energy EF fell at a level where most of the states were rare-earth 5d-eg conduction states while negligible contributions of both interstitial（tetrahedral and octahedral） H s-states were observed near EF. From electronic density, the bonding between Gd and tetrahedral H atoms was of prominent covalency, while was ionic between Gd and octahedral H atoms.
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