Wetting to Non-wetting Transition in Sodium-Coated C_60
  Based on ab initi and density-functional theory calculations, an empirical potential is proposed to model the interaction between a fullerene molecule and many sodium atoms. This model predicts homogeneous coverage of C_60 below 8 Na atoms, and a progressive droplet formation above this size. The effects of ionization, temperature, and external electric field indicate that the various, and apparently contradictory, experimental results can indeed be put into agreement. 
J. Roques, F. Calvo, F. Spiegelman, C. Mijoule