The adsorption geometry of various gases on top of a ${\text{C}}_{60}$ monolayer is investigated. The potential energy experienced by an adsorbate atom in the vicinity of a ${\text{C}}_{60}$ molecule consists of Lennard-Jones interactions integrated over the spherical surface of the molecule. The adsorption potential exhibits strongly attractive sites which lead to a commensurate phase. The next adsorption sites are assumed on the basis of the symmetries of the triangular ${\text{C}}_{60}$ array. The competition between different adsorption phases is solved by energy minimization. The onset pressure of each phase is computed and compared with experimental data for Kr on top of a ${\text{C}}_{60}$ monolayer.

• Received 25 July 2007

DOI:https://doi.org/10.1103/PhysRevE.77.041603