A systematic study of the surface energetics and structure of TiO 2(110) by first-principles calculations

Abstract

First-principles calculations based on density functional theory and the pseudopotential method have been used to study the surface energetics and structure of the TiO 2(110) surface. Periodically repeating slab geometry is used, and we have investigated the effect of variable vacuum width and slab thickness on the predicted surface energy and surface atomic displacements. We find that vacuum widths of only 4 Å are sufficient to converge the surface energy to within 0.01 J m −2. Slab thicknesses of at least 6 layers are necessary to achieve similar convergence of the surface energy. Predicted surface atomic displacements are found to differ significantly for slab thicknesses of four layers or less. The displacements are in semi-quantitative agreement with those from other calculations and a recent experimental study. However, in common with all other calculations, the displacement of the bridging oxygen is significantly underestimated when compared to the experimental value.