REALISTIC GRAND-CANONICAL MONTE-CARLO SURFACE SIMULATION - APPLICATION TO AR(111)

Most realistic, oh-lattice surface simulations are done canonically co nserving particles. For some applications, however, such as studying t he thermal behavior of rare gas solid surfaces, these constitute bad w orking conditions. Surface layer occupancies are believed to change wi th temperature, particularly at preroughening, and naturally call for a grand canonical approach, where particle number is controlled by a c hemical potential. We report preliminary results of novel realistic gr and canonical Monte Carlo simulations of the Lennard-Jones fcc(111) su rface, believed to represent a quantitative model of Ar (111). The res ults are successful and highly informative for temperatures up to roug hly 0.8 T-m, where clear precursor signals of preroughening are found. At higher temperatures, convergence to equilibrium is hampered by lar ge fluctuations. (C) 1998 Elsevier Science B.V. All rights reserved.