中国物理B ›› 2008, Vol. 17 ›› Issue (6): 2222-2228.doi: 10.1088/1674-1056/17/6/047

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Electronic structure and optical properties of LiXH3 and XLiH3 (X=Be, B or C)

伞晓娇, 何志, 马琰铭, 崔田, 刘冰冰, 邹广田   

  1. National Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
  • 收稿日期:2007-11-09 修回日期:2007-12-25 出版日期:2008-06-20 发布日期:2008-06-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10574053 and 10674053), the 2004 NCET and 2003 EYTP of MOE of China, the National Basic Research Program of China (Grant Nos 2005CB724400 and 2001CB711201), and the Cultivati

Electronic structure and optical properties of LiXH3 and XLiH3 (X=Be, B or C)

San Xiao-Jiao(伞晓娇), He Zhi(何志), Ma Yan-Ming(马琰铭), Cui Tian(崔田)†, Liu Bing-Bing(刘冰冰), and Zou Guang-Tian(邹广田)   

  1. National Laboratory of Superhard Materials, Jilin University, Changchun 130012, China
  • Received:2007-11-09 Revised:2007-12-25 Online:2008-06-20 Published:2008-06-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos 10574053 and 10674053), the 2004 NCET and 2003 EYTP of MOE of China, the National Basic Research Program of China (Grant Nos 2005CB724400 and 2001CB711201), and the Cultivati

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摘要： The equilibrium lattice constant, the cohesive energy and the electronic properties of light metal hydrides LiXH3 and XLiH3 (X=Be, B or C) with perovskite lattice structures have been investigated by using the pseudopotential plane-wave method. Large energy gap of LiBeH3 indicates that it is insulating, but other investigated hydrides are metallic. The pressure-induced metallization of LiBeH3 is found at about 120GPa, which is attributed to the increase of Be-p electrons with pressure. The electronegativity of the p electrons of X atom is responsible for the metallicity of the investigated LiXH3 hydrides, but the electronegativity of the s electrons of X atom plays an important role in the metallicity of the investigated XLiH3 hydrides. In order to deeply understand the investigated hydrides, their optical properties have also been investigated. The optical absorption of either LiBeH3 or BeLiH3 has a strong peak at about 5eV, showing that their optical responses are qualitatively similar. It is also found that the optical responses of other investigated hydrides are stronger than those of LiBeH3 and BeLiH3 in lower energy ranges, especially in the case of CLiH3.

关键词: plane-wave method, metal hydrides, electronic structure, optical properties

Abstract: The equilibrium lattice constant, the cohesive energy and the electronic properties of light metal hydrides LiXH3 and XLiH3 (X=Be, B or C) with perovskite lattice structures have been investigated by using the pseudopotential plane-wave method. Large energy gap of LiBeH3 indicates that it is insulating, but other investigated hydrides are metallic. The pressure-induced metallization of LiBeH3 is found at about 120GPa, which is attributed to the increase of Be-p electrons with pressure. The electronegativity of the p electrons of X atom is responsible for the metallicity of the investigated LiXH3 hydrides, but the electronegativity of the s electrons of X atom plays an important role in the metallicity of the investigated XLiH3 hydrides. In order to deeply understand the investigated hydrides, their optical properties have also been investigated. The optical absorption of either LiBeH3 or BeLiH3 has a strong peak at about 5eV, showing that their optical responses are qualitatively similar. It is also found that the optical responses of other investigated hydrides are stronger than those of LiBeH3 and BeLiH3 in lower energy ranges, especially in the case of CLiH3.

Key words: plane-wave method, metal hydrides, electronic structure, optical properties

中图分类号:  (Electronic structure (photoemission, etc.))

  • 74.25.Jb
71.15.Ap (Basis sets (LCAO, plane-wave, APW, etc.) and related methodology (scattering methods, ASA, linearized methods, etc.)) 71.15.Dx (Computational methodology (Brillouin zone sampling, iterative diagonalization, pseudopotential construction)) 74.20.-z (Theories and models of superconducting state) 74.25.Gz (Optical properties)