Comparison of stochastic and detrministic approaches to modelling of monomolecular thermal desorption process

The comparison of stochastic and deterministic approaches to the modelling of the CO moleculas thermal desorption from Ди(001) surface is fulfilled. The modelling is carried out in framework of the lattice-gas model taking into account the interactions of nearest and nextnearest neighbors on a triangular lattice. The stochastic model simulates the process on the base of dynamical Monte-Carlo method, the deterministic model uses quasichemical approximation and takes into consideration the $(\sqrt3\times\sqrt3)R\,30^\circ$ superstructure formation. The comparison shows, that these models provide quite identical results, which are in agreement with experimental results. The most disagreement between the stochastic and deterministic models is observed when the order-disorder phase transition takes place in the adsorbed layer. Several essentially different parameter sets were selected which provide good description of experimental data. The existence of such different parameter sets is explained in terms of adsorbate microscopic configurations.