摘要
Recently observed surfaces of α-PbO <sub>2</sub> -type TiO <sub>2</sub> , a stable phase under high pressure, were studied via first-principles density-functional calculations. The surface energy decreases at the order of (100) > (001) > (11̄0) > (010), in correlation with the undercoordination of Ti atoms with respect to neighboring O atoms, the distortion of the polyhedra, and atom-packing density of the surface. The (010) surface has the lowest surface energy due to the exposure of the highly symmetrical TiO <sub>4</sub> species. ©2005 The American Physical Society.