The unoccupied density of states is simulated for two different experimentally determined C 60 crystal structures. Several theoretical crystal structures are constructed to allow the effects of bond length and relative molecular orientation to be studied. It is found that both have an effect on the unoccupied states, and that the larger effect is coming from the variation in bond length. It is suggested that the difference previously reported in the electron energy loss spectra from C 60 thin films and nanocrystals could be due to differences in bond length, if these differences in bond length are sufficiently large.
