UO_2的电子结构及光学性质的第一性原理研究

First-principles study of the electronic structure and optical properties of UO_2

采用局域自旋密度近似(LSDA)和有效库仑相关能(U)方法研究了UO2的晶格参数、能带结构和光学常数.计算得到的UO2晶体的晶格常数为5.40,带隙宽度为1.82eV,正确预测了UO2的反铁磁性半导体基态性质.能带结构和介电函数的分析结果表明,铀的6d电子在晶体场中发生劈裂形成两个能级,与实验结果较为符合.

The electronic structure and optical properties of UO2 are investigated using the first principles density functional method within local-spin density approximation（LSDA）,and the Coulomb correlation energy（U） is used to calculate the lattice constant,energy band structure and optical properties of UO2.The calculated lattice constant is 5.40 x,and the band gap is 1.82 eV.We succeeded in predicting the correct anti-ferromagnetic insulating ground state of uranium dioxide.By analyzing the energy structure and dielectric function,we find that in uranium ions the 6d band splits into two sub-bands,which is in agreement with experimental results.