钨酸钡电子结构的第一性原理研究

通过基于密度泛函理论(DFT)框架下广义梯度近似平面波超软赝势法,优化了晶胞的几何结构,计算了白钨矿结构的BaWO4基态的能带结构和电子结构;研究发现:BaWO4为直接带隙结构,带隙宽带为4.5 eV,费米面处的价带主要由W5p和O2p态上电子构成,导带主要是W5d和O2p;根据晶体场理论和分子轨道理论分析了钨酸钡晶体的分子轨道成键,其结果与计算得到的态密度图能较好吻合。关键词:

Research on the First Principle of Electronic Structure of Barium Tungstate

Through general gradient approximate plane wave ultra-soft pseudopotential technology under the framework of density functional theory, geometric structure of unit space is optimized, BaWO of Tungstate mineral structure, energy band structure and electronic structure of its basic state are calculated, the research shows that BaWO has direct bandgap structure and its bandgap width is 4.5eV, that the valence band at Fermi surface is mainly composed of electrons on W5p and O2p state and that conduction band chiefly consists of W5d and O2p. According to crystalline field theory and molecular orbit theory, molecular orbit bonding of the crystal of Barium Tungstate is analyzed, the calculated results of which are better fitting for the state density pattern.