Influence of gradient corrections on the bulk and surface properties ofTiO2andSnO2

Abstract

First-principles calculations based on density-functional theory and the pseudopotential method have been used to investigate the influence of gradient corrections to the standard local-density-approximation technique on the equilibrium structure and energetics of rutile ${\mathrm{TiO}}_2$ and ${\mathrm{SnO}}_2$ perfect crystals and their (110) surfaces. We find that gradient corrections increase the calculated lattice parameters by roughly 3%, as has been found for other types of material. Gradient corrections give only very minor changes to the equilibrium surface structure, but reduce the surface energies by about 30%. © 1996 The American Physical Society.