What is ChemSpider?
I think that the SMILES for Buckminsterfullerene is not correct. While it is true that all the carbon atoms are identical, it is incorrect to ascibe to them the conventional (benzene) aromatic type. There are two types of bond; those that are in the five membered rings, and the "nearly double" bonds that join the five membered rings. A better SMILES is that one that is listed in "Molecular Modelling; Computational Chemistry Demystfied", p.279, Bladon , Gorton and Hammond, RSC Publishing 2011.
Also from the RSC