This is because the frequencies of vibrational transitions depend on the atomic masses and the bond strengths.
The spectra showed vibrational transitions with rotational fine structure.
Before we can apply these, however, we must define the symmetry of a vibrational transition rather more precisely.
Various other bands exists in each part of the spectrum due to different vibrational transitions.
A vibrational and rotational transition may be combined by rovibrational coupling.
Tables of vibrational transitions of stable and transient molecules are also available.
The lines corresponding to a given vibrational transition form a band.
The band spectrum is the combination of many different spectral lines, resulting from rotational, vibrational and electronic transition.
A reduction in intensity at a given wavelength of light indicates the absorption of energy by a vibrational transition.
Selection rules have been derived for electronic, vibrational, and rotational transitions.