A study is presented of the substrate-mediated dispersion interaction ΔV between two adatoms on graphite. Correspondence is made between one contribution to the McLachlan expression (ΔVM) (appropriate to a continuum substrate) and a discrete lattice result ΔV(3) for the three-body, triple dipole, dispersion energy involving the adatoms and the C atoms. The numerical results for these two functions agree closely for distances relevant to adsorption if the adatom position L is referred to an effective image plane at z0 = 1 A ̊ above the outermost C plane. With this choice, the complete McLachlan energy leads to a ∼10% reduction in the well depth of the interatomic potential.
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry