Retrieving "Symmetry Requirement" from the archives

Cross-reference notes under review

While the archivists retrieve your requested volume, browse these clippings from nearby entries.

1. Exchange Interaction

   Linked via "symmetry requirements"

   The sign of the superexchange interaction is determined by the bond angle ($\theta$) between the magnetic ions. For the common $\text{M-O-M}$ bond angle:
   If $\theta \approx 180^\circ$ (linear bond), the interaction is typically ferromagnetic.
   If $\theta \approx 90^\circ$ (right angle bond), the interaction is typically antiferromagnetic, due to the specific [symmetry requi…