Jahn-Teller effect in liquids: General principles and a molecular-dynamics simulation of the cupric ion in water

We discuss the general conditions under which a Jahn-Teller effect can be meaningfully associated with the solvation shell of an ion in solution. Unlike the Jahn-Teller effect in solids, no distortion of the solvation shell exists on the longest time scales. On intermediate time scales, the solvation shell exhibits cubic (${\mathit{O}}_{\mathit{h}}$) symmetry and on the shortest scales it shows the Jahn-Teller distortion (${\mathit{D}}_{4\mathit{h}}$). A molecular-dynamics simulation of a model in which the frame of reference for the Jahn-Teller potential rotates in time exhibits these features and shows how the time scales involved vary with parameters in the potential.