Modelling of SubPc Self-Assembly on Ag(111)

The ordering of subphthalocyanine molecules into honeycomb and hexagonal close packed patterns on Ag(111) is described using complex Lennard-Jones-type intermolecular potential. We rescale Ag(111) lattice, and take into account an infinite exclusion of first, second, and third neighbours, attraction - of fourth and fifth, and repulsion - of sixth and seventh. The phase diagram is obtained by the lattice gas model using Monte Carlo simulations. Very strong first order phase transitions, causing the two-phase co-existence, are found between disordered and honeycomb as well as between disordered and hexagonal closed packed phases.