Structures and Stabilities of Directly-linked and Oxygen-bridged Fullerene Dimers: A Density-functional-theory Study

The structures and the relative stabilities of the directly-linked fullerene dimer C-120 and of oxygen-bridged chillers of C120O and C120O2 are systematically investigated via density-functional-theory calculations. The structures of each dimer are identified as C-120(D-2h), C120O(C-2v), and C120O2(C-2v(I)) by comparing the total energies of geometric isomers. From dissociation-energy-barrier calculations, bridged dimers are more stable than directly-linked dimers. We find that the C-120 and the C120O dimers will dissociate into two fullerene units while the C120O2 dirtier remains at a certain energy range between 1.68 eV and 3.37 eV. Our theoretical results agree with the experimental data [J. Phys. Chem. B 110, 16979 (2006)].