Adsorption of C-82 on Si(100)

The interactions between C82 molecules and the Si(1 0 0) surface have been explored via ab initio total energy calculations. Configurations which have the cage located within the dimer trench bonded to four dimers (t4) and upon the dimer row bonded to two dimers (r2) have been investigated, as these were found to be most stable for the C60 molecule. It is found that the interactions between the surface and the C82 molecule are weaker than for the corresponding configurations for C60. The C82 cage has a far lower symmetry than the C60 cage and this gives many more unique rotational orientations of C82 compared with C60. We have, thus, investigated the binding energy when the local area of the C82 binding to the surface is the same but the cage orientation varies. We show that the binding energy can vary strongly within the configurations investigated. Bader analysis has been used to explain the relative binding energies of the different configurations.