Computer Simulations of Benzene Adsorbed on Graphite. 2. 298 K

Computer simulations of the structures and energies of benzene films on graphite at 298 K are reported. It is found that the observation of a nearly constant heat of adsorption in the submonolayer coverage region is the result of a cancellation of an increasing (negative) average benzene-benzene interaction energy by the decreasing (negative) average benzene-graphite energy. It is shown that the decrease in the benzene-graphite interaction on this homogeneous surface is a consequence of the changing orientation of the adsorbate molecules relative to the surface. Simulations at coverages up to two layers are reported. The role of molecular orientation in determining the energies and densities of bilayer films is briefly discussed. © 1991, American Chemical Society. All rights reserved.