Normal modes of vibration of the C60 isotopomers 12C5913C and 12C5813C2

The vibrational excitation spectra of the isotopomers 12C5913C and 12C5813C2 has been calculated within the framework of a first principle calculation. The force constants between the carbon atoms we obtained by performing the second derivatives of the energy within the Hartree–Fock approximation. A comparison of the frequency shifts in the vibrational spectra produced by the isotopes with Raman spectroscopy experiments is also presented.