Simulation of Raman spectra of C-60 and C-70 by non-orthogonal tight-binding molecular dynamics

A non-orthogonal tight-binding molecular-dynamics formalism is used to simu late Raman spectra of the fullerene molecules C-60 and C-70 Two parametriza tion schemes for the Hamiltonian and the overlap matrix elements are invest igated. The considered molecules are excited randomly and the Fourier trans form of the displacement autocorrelation function is employed to extract th e vibrational properties. Fair agreement with experiment and with force-con stant and ab initio calculations is achieved, with comparatively smaller ma ximum errors in the frequencies than for other molecular dynamics or semi-e mpirical calculations from the literature.