Analysing phonon spectra

[karthik_hj]

Hello,
I have used the DFPT method to plot a phonon spectra for a material. I also found some modes are Raman active among it. But how do you find which curve in phonon spectra corresponds to which mode. I want to find which curve in phonon spectra is corresponding to a Raman active mode and which doesn't. I am quite confused on the group theory symbols used for the same.

[martin.schlipf]

Could you be a bit more specific about the steps that you did and the input and output? Generally, one would connect these things via the eigenvalue of the modes but perhaps I'm missing something?