Fu Rong-Tang

Layer Structure of Doped C60

It is found in this letter that the doped C60 possesses layer-structure in both bond distortions and electronic states. There are eight layers of carbon atoms in the charged C60, and its symmetry is reduced from Ih to D5d. This layer-structure indicates that there exist four nonequivalent groups of carbon atoms in the doped C60. It contrasts with the pristine C60, in which all the sixty carbon atoms are equivalent. One observable consequence of such layer-structure is the split of its NMR spectrum with the ratio 1:1:2:2.

Bond structure and electron states of charged C60

In the alkali-metal doped C60, the charge transfer induces the distortion of the bond structure and forms the self-trapping electronic bound states. Our theory manifests: 1, the charge transfer reduces the symmetry of C60 from Ih to D5d. 2, Both the bond distortion and the self-trapping states possess layer structures and are localized in the equatorial area. 3, The carbon atoms in charged C60 are divided into eight layers with an inversion center, then there exist four nonequivalent groups of carbon atoms. It makes the NMR line split into a fine structure with strength ratio 1: 1: 2: 2. 4, The charged C60 has two self-trapping bound states, one is 0.06 eV above HOMO with odd parity and the other is 0.05 eV below LUMO with even parity.