COLLECTIVE DIFFUSION IN A LATTICE-GAS - APPLICATION TO O W(110)/

In this paper the diffusion of oxygen on the W(110) surface for covera ges theta less-than-or-equal-to 1/8 and at various temperatures T = 60 0, 800, 1000 and 1200 K is studied. In particular the energy width of the coherent dynamic structure factor and the chemical diffusion coeff icient, which are computed by using the Mori projection operator techn ique and neglecting memory effects, are presented. The energy width di splays a relative minimum at the border of the first Brillouin zone in the direction q = q(x)(1, 1/square-root 2).