Explaining the symmetry breaking observed in the endofullerenes H@C, HF@C, and HO@C.

Symmetry breaking has been recently observed in the endofullerenes M@C (M = H, HF, HO), manifesting in the splittings of the three-fold degenerate ground states of the endohedral ortho-H, ortho-HO and the j = 1 level of HF. The nature of the interaction causing the symmetry breaking is established in this study. A fragment of the solid C is considered, comprised of the central C molecule surrounded by twelve nearest-neighbor (NN) C molecules.