Ferromagnetism of two-bridge clusters

A generalized model of angular overlapping was used to analyze the magnetic properties of polynuclear complexes. The structural elements of these comp lexes contain planar binuclear fragments of the M(LR)(2)M type. The maximum ferromagnetism for the monoatomic bridges corresponds to theta = angle MLM , which is about 100 degrees. Weak planar sigma interactions between L and R displace the ferromagnetism maximum towards lower theta, while pi interac tions shift it towards higher theta. In almost all cases, strong planar int eractions (angle LLR similar to 180 degrees) are responsible for strong ant iferromagnetism.