求助：IR和Raman spectrum与键、角是怎样对应的？

jilin

我看了一篇文献，文章里做了IR和Raman spectrum，在分析时说谱峰值对应键或角的，这是怎样看出来的？比如文中这样说The Si8Y− cluster belongs to the C2 point group  symmetry. The frequency of the butterfly mode is calculated to be 112 cm−1. The strongest IR frequency at 340 cm−1 results from the antisymmetric stretching of
Si3-Y9 and Si5-Y9 bonds, as well as antisymmetric angle bending of Si8-Y9-Si3 and Si7-Y9-Si5 together. Two sharp peaks are calculated at frequencies 354 and 457 cm−1 in
the Raman spectrum. The first one is found to be a coupled mode that results from the symmetric stretching of Si3-Y9 and Si5-Y9 bonds, as well as symmetric angle bending of the Si8-Y9-Si3 and Si7-Y9-Si5 together. The second mode results from the symmetric stretching of Si2-Si5 and Si3-Si6 bonds.
不知道如何把截的图放上来？

sobereva

去挨个看每个振动模式的动画，直接就能判断出每个振动模式是如何对应于几何结构的改变

jiewei

这个我问题我还是有发言权的，第一，根据文献和自己的经验判断某些波段属于那些振动模式。第二算一下理论，然后挨着看到底属于什么振动模式

jilin

谢谢！