BOND-CHARGE-MODEL CALCULATION OF VIBRATIONAL PROPERTIES IN SMALL CARBON AGGREGATES - FROM SPHERICAL CLUSTERS TO LINEAR-CHAINS

The bond-charge model, originally devised to calculate the phonon spec trum of bulk semiconductors and extended with success to describe the vibrations of graphite and fullerenes C-60 and C-70, is applied to cal culate the normal modes of vibration of small carbon aggregates, as th e smallest fullerene (C-20), and odd-numbered linear and cyclic C-n cl usters (n = 5-19). The resulting spectra provide a satisfactory accoun t of the experimental findings and are in overall agreement with the r esults of ab initio calculations. [S0163-1829(98)02539-9].