Density functional study of Ni bulk, surfaces and the adsorbate systems Ni(111)(√3 x √3)R30°-Cl, and Ni(111)(2x2)-K

Nickel bulk. the low index surfaces and the adsorbate systems Ni(1 1 1)(root3 x root3)R30degrees-Cl, and Ni(1 1 1)(2x2)-K are studied with gradient corrected density functional calculations. It is demonstrated that an approach based on Gaussian type orbitals is capable of describing these systems. The preferred adsorption sites and geometries are in good agreement with the experiments. Compared to non-magnetic substrates, there does not appear to be a huge difference concerning the structural data and charge distribution. The magnetic moment of the nickel atoms closest to the adsorbate is reduced, and oscillations of the magnetic moments within the first few layers are observed in the case of chlorine as an adsorbate. The trends observed for the Mulliken populations of the adsorbates are consistent with changes in the core levels. (C) 2003 Elsevier B.V. All rights reserved.