中文摘要：

复杂分子的振动谱一般分为基团频率和指纹频率两部分,研究发现有些复杂分子其振动谱中指纹频率存在一定的对称性,例如作为分子探针的异硫氰基-孔雀石绿（malachite green isothiocyanate, MGITC）分子,其指纹频率具有U （5）对称性。本文介绍分子振动谱的U （5）模型并用其拟合MGITC低激发谱,发现理论与实验结果符合较好。

英文摘要：

The vibration spectra of complicated molecule are generally divided into group frequency and ridge frequency. The ridge frequency has a certain symmetry in the vibration spectra of some complicated molecules, such as the ridge frequency of malachite green isothiocyanate （MGITC） molecule which is a molecular probe and has a U（5） symmetry. In this article the U（5） symmetry of molecular vibration spectrum is introduced and tested for its fitting to the low excitation spectrum of MGITC, we find that the theoretical value conforms to the experimental results.