PREDICTION OF THE STRUCTURE AND THE VIBRATIONAL FREQUENCIES OF A C84 ISOMER OF D2 SYMMETRY

We report QCFF/PI quantum-chemical calculations of the molecular orbital energies, the structure, and the vibrational frequencies of a C84 isomer of D2 symmetry. Comparison with the results obtained by the same method for two C84 clusters of D6h and T(d) symmetry is given. The relative stability of the three isomers is D6h > T(d) > D2. The origin of this stability order is discussed. It is also found that the Raman and the infrared spectra of the three isomers should be rather different so that these spectra could be used to assign the molecular symmetry of this recently isolated novel form of carbon.