Ab initio quantum force field for simulations of nanostructures

It is demonstrated that the third generation of a recently introduced quantum mechanical polarizable force field (QMPFF) successfully reproduces experimental data on binding energies of polycyclic aromatic hydrocarbons and fullerene C-60 with graphite. The QMPFF also provides an accurate description of bulk graphite and solid C-60 properties. In all the studied systems, the electrostatics due to the penetration effect was found to be important and comparable in magnitude with the total interaction energy. The QMPFF predicts graphite exfoliation energy of 55 meV/atom in agreement with the relatively large experimental value of 52 +/- 5 meV/atom recently suggested by Zacharia [Phys. Rev. B 69, 155406 (2004)].