Superexchange

Similar to the direct exchange, superexchange calls for the combined effect of Pauli exclusion principle and Coulomb's repulsion of the electrons.

[2] A set of semi-empirical rules were developed by John B. Goodenough and Junjiro Kanamori [ja] in the 1950s.

[6] When multiple types of interactions are present simultaneously, the antiferromagnetic one is generally dominant, since it is independent of the intra-atomic exchange term.

[7] For simple cases, the Goodenough–Kanamori rules readily allow the prediction of the net magnetic exchange expected for the coupling between ions.

Complications begin to arise in various situations: Double exchange is a related magnetic coupling interaction proposed by Clarence Zener to account for electrical transport properties.

It has been proven, that due to the multiple energy scales present in the model for superexchange, perturbation theory is not in general convergent, and is thus not an appropriate method for deriving this interaction between spins [8] and that this undoubtedly accounts for the incorrect qualitative characterization of some transition-metal oxide compounds as Mott-Hubbard, rather than Charge-Transfer, insulators.