|
Ab initio calculations, based on pseudopotentials and density functional theory, have been made to investigate atomic and electronic structures of sulfur (S) and oxygen (O) on the NiAl(110)-(2x4) surface. We have assumed four possible locations for S or O on this surface: (i) on top of the Ni atom, (ii) on top of the Al atom, (iii) between the Ni atom and Al atom, and (iv) the cave region. We find that the latest site is energetically more favorable than all other cases studied here. The calculated bond length between O (S) and Ni is 1.97 Å (2.22 Å), which is in good agreement with other calculations. The calculated bond length between O (S) and Al is 1.79 Å (2.34 Å). We have also presented the reaction paths and adsorption energies for S and O atoms on the NiAl(110) surface. |