Density functional theory is used to calculate the bond dissociation energy to cleave the C 60 C 60 bond of the paramagnetic X–C 60 C 60 –X and X–C 60 C 60 dimers where X is F, OH, O and H. The results show that these dimers would not be stable much above room temperature and therefore cannot constitute the paramagnetic phase needed to form the observed ferromagnetism which has been shown to be stable up to 800K. The calculated bond dissociation energies to remove an F, OH or H from a single C 60 are large suggesting that they could be the source of the unpaired spin needed for the high temperature ferromagnetism.