钛原子位置对立方CaTiO_3电子结构的影响

Effects of Ti Atomic Location on the Electronic Structure of Cubic CaTiO_3

基于广义剃度近似(GGA)的从头算平面波超软赝势方法,计算了CaTiO_3晶体的晶格常数、总能量以及结合能,得到了与实验相一致的结果。分析了Ti原子Z坐标位置对CaTiO_3能带结构、态密度(DOS)等的影响。Ti原子位置强烈地影响CaTiO_3,的电子结构。随着Z坐标的增大,Ti的部分3d电子能量降低,O的部分2p电子能量升高,使价带与导带重叠,禁带消失。

Using ab initio plane waves uhrasoft pseudopotential method based on generalized gradient approximation （ GGA）, the lattice constant is calculated of CaTiO3, the total energy and the cohesive energy, the former of which is in good agreement with the experimental value, and then analyzed the effects of Ti atomic Z coordinate on the energy structure and Density of State of CaTiO3. The electronic structure of CaTiO3 was influenced intensely by the location of Ti atom. With the increasing of the Z coordinate, the energy of some Ti 3d electrons decreased, meanwhile, the energy of some O2p electrons increased, which made the overlap of the valence and conduction bands and thus disappearance of the band gap.