Structures and stabilities of asymmetric fullerene dimers: A density functional theory study

The molecular structure and the relative stability of asymmetric fullerene dimers were systematically investigated using density functional theory calculations. The most stable geometries for a directly-linked dimer of C-130, and bridged dimers of C130O and C-131 were identified among several isomers by using a total energy comparison. The relative stability of asymmetric dimers was defined by calculating the dissociation energy barrier of a fullerene dimer into two unit fullerenes. We found that the directly-linked asymmetric dimer C-130 was not energetically stable and that the carbon-bridged dimer C131 was more stable than the oxygen-bridged dimer C130O. The electronic structures of the stable asymmetric dimers were also investigated.