FeS_2(pyrite)电子结构与光学性质的密度泛函计算

Density Functional Calculation of Electronic Structure and Optical Properties of FeS2(Pyrite)

采用局域密度近似的自洽密度泛函理论计算了FeS_2的电子结构与光学性质。费米能级附近区域的能带与态密度计算表明价带极大值在X(100)点和导带极小值在G(000)点,直接带隙和间接带隙分别为0.74eV、0.6eV。并用电子结构信息精确计算了介质极化矩阵元,从而给出了FeS_2的介电函数虚部及相关光学参量,理论结果与实验符合甚佳。

The electronic structure of FeS2 (pyrite) has been studied using self-consistent density-functional theory within the local density approximation (LDA). The calculated band structure and density of states in the region around the Fermi energy show that valence-band maximum (VBM) is at the X point (100), and the conduction-band minimum (CBM) is at G (000). The indirect and direct band gaps are 0. 60 eV and 0. 74 eV, respectively. Moreover, with electronic structure information, polarization matrix elements of the medium have been calculated precisely. The imaginary part of dielectric function and other optical parameters have been given. Theoretical results are in good agreement with experiment.