Resonance Raman for several excited states

The numerical evaluation of resonance Raman intensities has the advantages that

• Relative Intensities can be computed for several excited states at a time,
  since all excitation energies are determined simultaneously.
• Intensities can be computed for a selected no. of modes.

The intensities calculated for two different states cannot directly be compared, since the excited-state gradients only provide relative intensities for each excited state in resonance. For RR intensities from different excited states, also other quantities play a role. The most important one is the transition dipole moment to the excited state in resonance, which enters the intensity expression with to the fourth power.