利用密度泛函理论(Density Functional Theory,DFT)中杂化泛函(B3LYP)理论方法,计算了CH2和CH3自由基吸附在Cun(n=1-6)团簇上时C-H对称伸缩振动模式的软化性质,结果表明,CH2在Cun团簇上的吸附要比CH3的吸附强.计算得到的C-H键的振动频率与实验上测量的这两个自由基吸附在Cu(111)表面的结果符合地很好,随着团簇尺寸的增加,C-H对称伸缩振动频率的软化(红移)越来越大. The CH symmetric stretching vibrational modes of CH2 and CH3 radicals adsorbed on Cun (n = 1-6) clusters were calculated using the hybrid functional theory (B3LYP) in Density Functional Theory (DFT) The results show that the adsorption of CH 2 on Cun clusters is stronger than that of CH 3. The calculated vibrational frequencies of CH bonds are in good agreement with the experimentally measured results of these two free radicals adsorbed on the Cu (111) surface Well, as the size of the clusters increases, the softening (redshift) of the CH symmetrical stretching vibrational frequencies becomes larger and larger.