ok I see. Thanks.
Is it then one of these that are the ground state (E1u + A2u aproaches zero energy, so i guess one of them are), or is it still A1g?
If it is one of them, which is it I should use to calculate if a given transition is raman active, and why?
If they are not, how come the ground state is not included in the allowed vibrational modes? I seem to fail to see where the symmetry analysis exclude the ground state of the analysis, if this is the case?