Circular dichroism spectra, predicted

The two principal resonance limits of the theory of ROA are the far-from-resonance (FFR) limit, the original form of the theory of ROA, and the single-electronic-state (SES) limit, for the case of strong resonance between a single excited electronic state and the incident laser radiation. In the case of FFR ROA, ab initio calculations have been carried out for direct comparison with experiment. The SES theory is so simple that the complete SES-ROA spectrum can be predicted from the parent resonance Raman spectrum and the electronic circular dichroism spectrum of the resonant electronic state. 

Circular dichroism (CD) can be observed in the vibrational transitions of chiral molecules vibrational circular dichroism (VCD). An example of a VCD spectrum is shown in Figure 1, together with the corresponding unpolarized absorption spectrum. The sample is a 0.6 M solution of (lR,4jR)-(-i-)-cam-phor in CCI4. Here, we discuss the theoretical analysis of VCD spectra. The current state-of-the-art is illustrated in Figure 1, where VCD and absorption spectra of camphor, predicted within the harmonic approximation (HA) using ab initio density functional theory (DFT), are shown. 

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