Editing Selection rule (section)

=== Rotational spectra ===
{{Main|Rigid rotor}}
The [[rigid rotor#Selection rules|selection rule]] for rotational transitions, derived from the symmetries of the rotational wave functions in a rigid rotor, is Δ''J'' = ±1, where ''J'' is a rotational quantum number.<ref>{{cite book |last=Kroto |first=H. W. |title=Molecular Rotation Spectra |publisher=Dover |location=New York |date=1992 |isbn=0-486-49540-X }}</ref>