A distortion of a molecule that forces the molecule to adopt a shape in which valence molecular orbitals are not degenerate. This effect is sometimes regarded as an example of spontaneously broken symmetry. Examples of the Jahn–Teller effect include certain transition metal complexes in which metal ions surrounded by six ligands are distorted octahedra rather than regular octahedra. Jahn–Tellar splitting is the splitting of spectral lines as a result of this effect. H. A. Jahn and Edward Teller predicted this effect in 1937 using group theory.
Subjects: Chemistry — Physics.