 Jahn-Teller stabilization energy

The positive energy reduction from a symmetry-lowering Jahn-Teller effect, measured from the undistorted reference configuration. In the harmonic linear-coupling model $E(Q)=-\alpha Q+\beta Q^2/2$, with $\alpha ,\beta >0$, completing the square gives $Q_0=\alpha /\beta$ and $E(Q_0)=-{\alpha }^2/(2\beta )$. Relating this local energy directly to a cooperative transition temperature is an extra approximation.