First principles study of the electronic structure of ReSi1.75
ReSi1.75电子结构的第一性原理研究

First principles full-potential linearized augmented plane wave method with local density approximation(LDA)was applied to calculate the ground state properties of ReSi_ 1.75 crystal.Optimized results show that the equilibrium lattice constant of ReSi_ 1.75 is smaller than experimental data by about 0.6%.On the basis of LDA results,LDA U method was used to calculate the electronic structure.When U_ eff=U-J=4.4?eV,ReSi_ 1.75 has a narrow gap semiconductor band structure with an indirect gap of 0.12 ?eV and a direct gap of 0.36?eV.Effective mass calculation shows the highly anisotropic character of ReSi_ 1.75 crystals.The density of sates changes sharply near Fermi level,thus the thermoelectric properties can be improved by doping.