Adsorption of S, O, and H on the NiAl(1 1 0)-(2x2) surface

We present results of ab initio calculations, based on pseudopotentials and density functional theory, for adsorption of sulfur (S), oxygen (O), and hydrogen (H) on the NiAl(1 1 0)-(2x2) surface. For the S, O, and H atoms, various adsorption sites are considered: (i) Ni-Ni short bridge, (ii) on top of the Ni atom, (iii) Al-Al short bridge, (iv) on top of the Al, and (v) between the Ni atom and Al atom regions. We find that adsorption site for S and H are found to be at the 2Ni-Al threefold minimum and O is found to be at the 2Al-Ni threefold minimum. The calculated key parameters are in good agreement with other calculations. We also present the reaction paths and adsorption energies for S, O, and H atoms on the NiAl(1 1 0) surface.