The structural and electronic properties of yittria are studied by density functional theory calculations. The results agree well with the experimental ones. Based on the supercell method, the intrinsic and Eu-doped defects are investigated. Analyzing the formation energies of various defects, we find that the Eu atom substitutes for the cations more easily under the O-rich condition. The b-site as an inversion center is preferred with the lower Fermi energy, while the probability of the d-site with lower symmetry is equal to that of b-site. The results are instructive to improve the luminous efficiency.
