Abstract The electronic structure and optical properties of rutile TiO2 under hydrostatic pressure are reported based on the first-principle calculations. The results indicate that both the lattice constants and the volume of TiO2 decrease with pressure increasing; however, the ratio of c/a is almost unchanged in such a case and the TiO6 octahedron in the unit cell transforms into regular octahedron at about 22.0 GPa. It is also shown that the band-gap of rutile TiO2 enlarge along two stages and the peak value of electronic states reduce with pressure, and these variations are found to be associated with the expansion of the O 2p and Ti 3d electronic states. Besides, we also calculated and analyzed the dielectric function of TiO2 under different hydrostatic pressure and the results indicate that the peaks in the imaginary part of dielectric function move to higher energy direction with pressure.

中文翻译：

---

静水压力下金红石型TiO2电子结构和介电函数的第一性原理计算

摘要 基于第一性原理计算，报道了静水压力下金红石型TiO2的电子结构和光学性质。结果表明，随着压力的增加，晶格常数和TiO2的体积均减小；然而，在这种情况下，c/a 的比率几乎没有变化，晶胞中的 TiO6 八面体在约 22.0 GPa 时转变为正八面体。还表明金红石型TiO2的带隙沿两个阶段扩大，电子态的峰值随压力减小，这些变化与O 2p 和Ti 3d 电子态的扩展有关。除了，