Abstract: Electronic structure and optical properties of A-La₂O₃ are investigated with plane waves ultrasoft pseudopotential technique in density functional theory (DFT).Calculated results show that A-La₂O₃ is indirect oxide with a band gap of 3.72 eV.Valence bands of A-La₂O₃ are composed of La-5s,La-5p,La-6s,O-2s,O-2p and the conduction bands are mainly composed of La-5d.With band gap correction,optical linear response functions of A-La₂O₃ as a function of photon energy are obtained including complex dielectric function,complex of refractive,absorption coefficients,reflectivity,loss function and complex conductivity function in(100) and(001) directions.It shows that A-La₂O₃ shows optical anisotropy in polarization directions(100) and(001),and A-La₂O₃ is high transmission from near-ultraviolet to infrared,which offers a theoretical basis for applications.

Key words: A-La₂O₃, electronic structure, optical properties, first-principles