The coupling can be observed spectroscopically and is most easily seen in the Renner–Teller effect in which a linear polyatomic molecule is in a degenerate electronic state and bending vibrations will cause a large rovibronic coupling.
The interaction can be observed spectrally, and is most clearly demonstrated by the Renner–Teller effect in which a linear polyatomic molecule is in a degenerate electronic state and bending vibrations will cause significant rovibrational coupling.