FIRST-PRINCIPLES DETERMINATION OF THE DISPERSION INTERACTION BETWEEN FULLERENES AND THEIR INTERMOLECULAR POTENTIAL

We compute, from first principles, the dispersion interaction between two and three fullerenes, in time-dependent density functional theory. These results, complemented with total energy calculations at small a nd intermediate distances, lead to a parameter-free determination of t he interaction between fullerenes. Agreement with experiment, within 4 %, is found for all quantities, computed via Monte Carlo simulations o f fullerite. Inclusion of the three-body term is found to increase by 6% the cohesive energy at equilibrium density.