BeO电子结构的第一性原理研究

First-principle Study of Electrnic Structure of BeO

采用基于密度泛函理论的第一性原理平面膺势法对BeO电子结构进行了研究。结果表明,(1)BeO在-18.1eV、-15.4eV和-7.366eV价带区域存在p-s和p-p轨道杂化现象,解释了BeO分子能够稳定存在的部分原因;(2)Be原子与O原子形成共价成分,具有较高的共价键,其中共价键的比例为63.5%,离子键的比例为36.5%;(3)BeO吸收光谱的最强吸收峰位于16.75eV左右,与态密度分布图中价带与导带对应的跃迁能量中有3个与吸收光谱中的峰值基本对应。

The electronic of BeO have been calculated by first-principles ultra-soft pseudopotential approach of the plane wave based upon the density-functlonal theory. The bandstructure, the density of state, the atomic populations and absorption were studied. The calculated results reveal that BeO with its direct band gap around 6. 874eV. The lower value band of BeO is mainly contributed by the 2p electrons of Be, upper value band by the 2p electrons of O and conduction band by the 2p and 2s electrons of Be, Be-O being convalent bond of 63.50% and ion bond of 36. 5%. Moreover, the 3 peaks of the absorption spectra corresponding with the peaks of electionic transition have been stu died.