Study on the Electronic Structure and Optical Properties for BaSi2

The electronic structure, densities of states and optical properties of the stable orthorhombic BaSi
₂
have been calculated using the first-principle density function theory pseudopotential method. The results show that BaSi
₂
is an indirect semiconductor with the band gap of 1.086 eV, the conduction bands are mainly composed of Ba 6s, 5d as well as Si 3p, the valence bands of BaSi
₂
are mainly composed of Si 3p, 3s and Ba 5d. The calculated dielectric function of BaSi
₂
shows that it possesses anisotropic character, the biggest peak of absorption coefficient is 2.15 times 10
₅
cm
^-1
.