For a spherical top molecule in which all three axes are equivalent, symmetric vibrations have Raman spectral bands which are completely polarized (ρ = 0). An example is the symmetric stretching or "breathing" mode of methane (CH 4) in which all four C−H bonds vibrate in phase. However, for the asymmetric mode in which one C−H bond stretches while the other three contract, the Raman scattered radiation is depolarized.