中文摘要：

从第一原理角度，用基于密度泛函理论（DFT）的全电势线性缀加平面波法（FLAPW）和广义梯度近似（GGA），计算了掺Sn锐钛矿相TiO2的晶格优化结构和电子结构。结果表明：掺Sn以后晶胞体积明显增大，在z方向有伸长的趋势；掺Sn锐钛矿相TiO2典型晶面的电子密度分布与纯的锐钛矿相TiO2的比较表明，掺杂后的Sn-O键比原来的Ti-O键强；掺Sn锐钛矿相TiO2的能带结构图表明，掺杂后仍为间接带隙的半导体，与未掺杂时比较，能隙减小了0．24 eV，与实验趋势相符。

英文摘要：

We calculate the optimized structure and electronic structure of the Sn doped anatase TiO2 using the Full-potential Linearized Augmented Plane Wave method （FLAPW） in the frame of Density Functional Theory （DFT） with the Genralized Gradient Approximation （GGA）. The results indicate that the unit cell of the Sn doped anatase TiO2 is larger than that of the pure one, and is stretched in z-axis. The comparison of the charge densities between the doped and the pure system shows that the chemical bond of Sn and O is stronger than that of Ti and O. With the optimized structure, we also get the band structure of the Sn doped anatase TiO2. The narrowing trend of energy gap agrees with the experiment, which maybe helpful for understanding of this system.