[xshadow]

HI

I have a doubt about the vibrational modes...

If I have a centrosymmetric molecule can I have a vibrational mode that is not active both in RAMAN and IR??
Because I know that for centrosymmetric molecules If a normal mode is active in IR shouldn't be  in raman (and vicevresa)

But if I discover for a centrosymmetric molecule that a certain vibrational mode isn't IR actvie can i say aoutomatically that that mode is active in RAMAN?

thanks!

[Corribus]

https://en.wikipedia.org/wiki/Rule_of_mutual_exclusion

[xshadow]

https://en.wikipedia.org/wiki/Rule_of_mutual_exclusion

I found the answer!
""This does not mean that a vibrational mode which is not Raman active must be IR active: in fact, it is still possible that a mode of a particular symmetry is neither Raman nor IR active""

Thanks!