The structural, electronic, and chemical properties of the SrTiO3(001) surface were examined by means of first principles density-functional (DF) slab calculations (LDA, GGA Perdew-Burke-Ernzerhoff functional). In qualitative terms, the LDA and GGA predict similar structural relaxations for the SrTiO3(001) system. DF results for bulk SrTiO3 and SrTiO3(001) illustrate the important effects that metal <----> oxygen <----> metal interactions can have on the electronic and chemical properties of a mixed-metal oxide. A big increase in the electron density of Ti is found when going from TiO2 to SrTiO3. This phenomenon can easily explain why SrTiO3 is a much better DeSO(x) catalyst than pure TiO2. (C) 2002 Published by Elsevier Science B.V.