Electronic structure and linear optical properties of YAl3(BO3)4

The electronic structure and linear optical properties of YAl3(BO3)(4) (YAB) crystal are calculated by density functional method with the local-density approximation. An indirect band gap of 6.54 eV and a direct gap of 6.91 eV at M are obtained for YAB. The calculated total and partial densities of states indicate that the top valence band is constructed from O 2p, B 2s, and B 2p states and the low conduction band mostly consists of Y 4d and B 2p states. The calculated linear optical properties, such as refractive index and absorption spectrum, are in good agreement with experimental values.