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 (Oh) symmetry and on the shortest scales it shows the Jahn-Teller distortion (D4h). 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.