The (1x4) reconstruction of the stoichiometric anatase TiO2(001) surface was studied via first principles density functional calculations. A new structural model was proposed for this reconstruction, which was energetically much more -favourable than all the other available models, including the unreconstructed (1x1) surface. In this model, rows of TiO3 species periodically replace rows of surface bridging oxygen atoms of the (1x1) surface, thus leading to a relief of the large surface tensile stress present on that surface. The corresponding empty-state charge density distribution correctly describes the experimental scanning tunnelling microscopy images.

Stress-Driven Reconstruction of an Oxide Surface - the Anatase TiO2(001)-(1 x 4) Surface. Lazzeri, M., Selloni, A.: Physical Review Letters, 2001, 87[26], 266105