Interactions of graphene sheets deduced from properties of polycyclic aromatic hydrocarbons

摘要

Intermolecular interactions of coronene dimer were studied with symmetry-adapted perturbationtheory based on the density functional theory description of the monomers [SAPT(DFT)]. The moststable stacked structure was found to have the interaction energy of —17.45 kcal/mol, slightly lowerthan the structure analogous to graphite (-17.36 kcal/mol). The latter energy was extrapolated tothe interaction energy of two graphene sheets. The effects of interactions of multiple layers werealso estimated leading to the exfoliation energy of graphite equal to 45.3 meV per carbon atom. TheSAPT(DFT)-based decomposition into physical quantities of the interaction energies shows thedominant effect of the dispersion interactions with a weaker electrostatic contribution due topenetration effects. The extrapolated physical picture of the graphene-graphene interaction is verysimilar to that of smaller stacked polycyclic aromatic hydrocarbons.