Abstract: The crystal structure,electronic structure and optical properties of pure rutile TiO2,Ce/Nd/Eu/Gd doped rutile TiO2,and Ce/Nd/Eu/Gd and N co-doped rutile TiO2 were investigated by the first-principles calculation method based on density functional theory.The results show that the unit cell expands,the lattice distorts in the doping systems.After doping the impurity into rutile TiO2,the Fermi level rises and gets through conduction band,and impurity level appears at the bottom of conduction band,which dues to improving the conductivity and the responsiveness of visible light.From the optical properties calculation,it is known that the peak of the curves of the dielectric function and the absorption spectrum is less than that of pure system,and the red shift appears in the reflectance spectrum and the energy loss spectrum.

Key words: The crystal structure,electronic structure and optical properties of pure rutile TiO2,Ce/Nd/Eu/Gd doped rutile TiO2,and Ce/Nd/Eu/Gd and N co-doped rutile TiO2 were investigated by the first-principles calculation method based on density functional theory.The results show that the unit cell expands,the lattice distorts in the doping systems.After doping the impurity into rutile TiO2,the Fermi level rises and gets through conduction band,and impurity level appears at the bottom of conduction band,which dues to improving the conductivity and the responsiveness of visible light.From the optical properties calculation,it is known that the peak of the curves of the dielectric function and the absorption spectrum is less than that of pure system,and the red shift appears in the reflectance spectrum and the energy loss spectrum.