Cmcm空间群斜方SrHfO_3的电子结构和光学性质理论计算（英文）

Theoretical Calculations on Electronic Structure and Optical Properties of Orthorhombic SrHfO_3 in Cmcm Space Group

采用基于密度泛函理论(DFT)框架下广义梯度近似平面波超软赝势法,计算了Cmcm空间群斜方SrHfO_3的电子结构和光学性质。计算得到的Cmcm斜方SrHfO_3的平衡晶格常数均与实验值相近。同时,计算得到了Cmcm斜方SrHfO_3的能带结构、态密度和电荷密度。结果表明,斜方SrHfO_3属于直接带隙氧化物,在Hf和O之间主要是共价键结合而在Sr和O之间主要呈现离子键特性。计算还得到了斜方SrHfO_3的复介电函数、折射率和消光系数等,且复介电函数的实部与虚部都与实验结果接近。

Electronic structure and optical properties of Cmcm orthorhombic SrHfO3 were computed, using the plane-wave ultrasoft pseudopotential technique based on the first-principles density functional theory（DFT）. The equilibrium lattice parameters of orthorhombic SrHfO3 are in good agreement with experimental values. The band structure, the densities of states（DOS） and charge densities of Cmcm orthorhombic SrHfO3 have been obtained. The band structure shows that Cmcm orthorhombic SrHfO3 has direct band gap. The charge densities of Cmcm orthorhombic SrHfO3 indicate that bonding between Hf and O is mainly covalent whereas the bonding between Sr and O is mainly ionic. The complex dielectric function, refractive index and absorption coefficient of Cmcm orthorhombic SrHfO3 have been predicted. The imaginary and real parts of the calculated complex dielectric function are close to the results of experimental measurements.