Linked from
The 25 pages that link to Molecular vibration, each with the reason it gives.
SpectroscopyRelated: Vibrational transitions produce characteristic infrared absorption bands.
Energy levelRelated: Quantized vibrational states form characteristic molecular energy levels.
Zero-point energyRelated: Even at zero temperature, vibrational modes retain zero-point energy.
MoleculeRelated: Molecules continually vibrate, and their vibrational modes reveal bond properties.