https://doi.org/10.1351/goldbook.08667
Inelastic scattering of electromagnetic radiation by molecules that are excited to higher energy levels.
Notes:
- Normal Raman scattering occurs through changes in polarizability of a molecule during a vibration, not the hyper-polarizabilities, and is excited by radiation that is not in resonance with electronic transitions in the sample.
- The energy of the scattered photon can be lesser (Stokes Raman scattering) or greater (anti-Stokes Raman scattering) than that of the incident photon.