The 2-position model introduced by Myshlyavtsev & Zhdanov (1990) was analyzed in detail. The model was a simplified lattice-gas version of the H/W(001) system, which presented a c(2 x 2) ordered structure below the critical temperature Tc. The phase diagram of the real system was reproduced only at low coverage (θ < 0.4). The phase diagram was obtained by the mean-field approximation as well as by Monte Carlo simulations through finite-size scaling techniques. Different kinds of situations could be observed depending on the characteristics of the metal-metal, adsorbate-adsorbate and metal-adsorbate interactions.

Adsorption-Induced Surface Reconstruction - Predictions of a Simple Model. F.Nieto, V.Pereyra: Surface Science, 1997, 383[2-3], 308-20