A first-principles study of the effect of charge doping on the 1D polymerization of C ₆₀

We study the interplay between charge doping and intermolecular distance in the polymerization of C ₆₀ fullerene chains by means of density functional theory-based first-principles calculations. The potential energy surface analysis shows that both the equilibrium intermolecular distance of the unpolymerized system and the polymerization energy barrier are inversely proportional to the electron doping of the system. We analyze the origin of this charge-induced polymerization effect by studying the behavior of the systems wavefunctions around the Fermi level and the structural modifications of the molecules as a function of two variables: the distance between the centers of the molecules and the number of electrons added to the system.