苯、吡啶及吡嗪分子的超拉曼和表面增强超拉曼光谱

用量子化学从头算法计算了苯、吡啶及吡嗪分子的超粒曼和表面增强的超拉曼光谱，并比较了理论计算与实验测量的结果，用Gaussian98中的密度泛函的方法计算分子的偶极矩、极化率和超极化率以及偶极矩、极化率的导数，而超极化率的导数则有限差分的方法来计算，为了检验有限差分法的准确性，用该方法计算了上述分子的红外和拉曼光谱，其结果与Gaussian98的计算结果高度一致，建立了基于有限差分法计算分子红外，拉曼，表面增强拉曼。超拉曼和表面增强超拉曼的光谱强度的方法，并编写了计算程序。

HYPER-RAMAN AND SURFACE ENHANCED HYPER-RAMAN SPECTRA OF BENZENE, PYRIDINE AND PYRAZINE

The hyper-Raman and surface enhanced hyper-Raman spectra of benzene, pyridine and pyrazine were calculated by ab initio method. The results of theoretical calculation and experiments were compared. The molecular dipole moments, the polarizabilities, and hyper-polarizabilities were calculated by using density functional theory (DFT) methods based on Gaussian 98. The dipole moment and polarizability derivatives were provided automatically by Gaussian 98, but the hyper-polarizatibily derivatives were determined by a finite difference method. To make sure the accuracy of this method, it was used to calculate the infrared (IR) and Raman spectra, and the results are in agreement with the analytical results provided by Gaussian 98. The methods for calculating spectra of IR, Raman, surface enhanced Raman scattering (SERS), hyper-Raman scattering (HRS), and surface enhanced hyper-Paman scattering (SEHRS) of molecules were built up based on ab initio and the finite difference method.