A FAST-CONVERGENT MONTE CARLO METHOD FOR SURFACES WITH HIGH POTENTIAL BARRIERS TO MOVEMENT OF ADATOMS

A new Monte Carlo method is described that is suitable for studies of adsorption systems in which the movement of adatoms is hindered by large potential barriers. The technique involves the possibility of a "jump" of a particle by one lattice vector of the substrate. The method is tested on a model for studies of commensurate-incommensurate transitions. It is shown that the modification leads to considerable advantages in terms of convergence, as indicated by control charts for the mean potential energy and the mean displacement of the particles from the nearest commensurate site for a system with a potential barrier of 6(dagger). Results are presented for three values of the fractional coverage (theta = 0.667, 0.833 and 0.958 with respect to the commensurate monolayer) and for two values of the inter-particle Lennard-Jones parameter epsilon* (epsilon* = 3 and 8).