Computational investingation for Raman vibration modes of C₆₀ molecule

Vibrational property of a molecule is of importance to identify the micro-structure of a matter. Raman spectra can correctly indicate the resonance frequencies of molecular vibration with polarized characters. Although the experiments can provide the resonance frequencies, the modes of molecular vibration can not be measured by experiment. Only theoretical or computational analyses can be used to investigate the vibrational modes. Group theory is a common tool to deal with this issue, but with very complicated procedure and more skills. Based upon the principle of molecular mechanics, the paper develops a computational element to describe the force-energy relation of a C-C covalent bond, called Carbon-Carbon Bonding Element (CCBE). This element is used to model the C₆₀ molecule and compute its vibrational modes. The total modes corresponding to Raman spectra are presented. The resulting resonance frequencies are compared to experiments with a good agreement. The reasonable force constants of C-C bond are given. The research results show that the CCBE is an effective and practical method.