Surface relaxations and electronic structures of (001) surfaces of cubic ${\mathrm{SrTiO}}_3$ have been studied by first-principles total-energy calculations with the generalized-gradient approximation. Both ${\mathrm{TiO}}_2$-terminated (surface-I) and SrO-terminated (surface-II) surfaces are investigated and the atomic configurations have been fully relaxed. We show that both surfaces show a first-layer buckling, with oxygen ions being pulled out of the surface and a relaxation of the interlayer distances.

• Received 17 March 1998

DOI:https://doi.org/10.1103/PhysRevB.58.8075