C_(60)分子Raman活性振动模态的计算分析  

Computational investingation for Raman vibration modes of C_(60) molecule

作　　者：曾攀[1] 杨学贵[1] 杜婧[1] 

机构地区：[1]清华大学机械工程系,北京100084

出　　处：《振动工程学报》2007年第2期185-188,共4页Journal of Vibration Engineering

基　　金：国家自然科学基金资助项目(10172054)

摘　　要：分子的振动特征是标定微观物质结构的重要手段,Raman光谱可以准确地测定分子振动的具有极化率的特征频率,而相应的振动模态则需要采用理论分析或计算来得到,群论方法是计算分子振动特征的主要方法,但它的分析过程非常复杂,在应用中具有较大的难度。本文在分子力学原理的基础上,针对碳-碳共价键给出相应的能量描述关系,建立了完整的碳-碳键合单元,并应用于C60分子的振动分析和计算,给出了C60分子Raman活性振动模态的计算结果,与相应的实验结果进行了比较,验证了本文所提出建模方法的正确性和实用性,基于实验数据还得到碳纳米材料中的碳-碳共价键的力常数,为分析具有共价键的纳米分子的振动性能提供一种简洁、高效的计算分析方法。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.

关 键 词：分子振动 拉曼光谱 C60分子 碳-碳键合单元 

分 类 号：O561.3[理学—原子与分子物理] O321[理学—物理]