Density functional theory of superionic conductor surfaces

Abstract We have computed structural properties of the (100) surface of the superionic conductor α - AgI using the density functional formalism. Ag + -ions are regarded as a charged liquid experiencing an external potential due to the lattice of I - -ions. In contrast to the bulk, the Ag + -density near the surface depends strongly upon correlations among cations which lead to oscillations in the Ag + -occupation of lattice planes below the surface. We also give estimates of the ionic and electronic surface polarization.