The Jahn–Teller Effect in Molecules and Crystals

Abstract

The Jahn–Teller effect has come to include almost all manifestations of the coupling of degenerate electron states to nuclear vibrations. The original theorem showed that there should be an instability, namely that for any orbitally degenerate molecule or complex (linear systems and Kramers' degeneracy excluded) there will be a distortion which lowered the symmetry and lowered the total energy.