Band theory of the magnetic interaction in MnO, MnS, and NiO

The interatomic coupling of magnetic moments in the insulating antiferromagnetic transition-metal compounds MnO, MnS, and NiO is calculated using a theory based on the itinerant-electron picture (energy-band theory and the local-spin-density treatment of exchange and correlation). Calculated values of these "Heisenberg" coupling constants agree with measured values to the extent that can be expected in light of the approximations required to execute the calculations. The calculations emphasize the importance of covalent interactions between the metal d states and the anion p states. These interactions are spin conserving and fundamentally nonmagnetic; they enter the coupling of the magnetic moments because the intra-atomic spin splitting of the metal d shell makes the covalent interactions dependent on the relative angle of the two magnetic moments. © 1983 The American Physical Society.