Band structure study on LiBeH3-y

摘要

In the present work, the band structure calculations on LiBeH3-y were carried out by employing the tight-binding method based on the extended Huckel molecular orbital (EHMO) approach, and the effect of hydrogen vacancies on the electronic structure of the system was studied. For LiBeH3, without hydrogen vacancies, its band structure has an energy gap of about 2.5 eV near the Fermi level, which reveals that it is a semiconductor or an insulator. If hydrogen vacancies are involved in the system, they result in a downward displacement of the band structure of LiBeH3-y and cause its total density of states at the Fermi level to be increased. In this case, there is no energy gap near the Fermi level and the total density of states for LiBeH3-y bears a strong resemblance to that for a high-temperature superconductor, which implies that LiBeH3-y is similar to a high-temperature superconductor in physical property. (C) 1998 John Wiley & Sons, Inc. [References: 14]