Magnetic Transition-State Approach to Antiferromagnetic Ordering: NiO

Antiferromagnetic ordering in insulating transition-metal compounds is explored in the magnetic transition state scheme proposed by Slater. A model is developed in the framework of a spin-polarized, one-electron, self-consistent, molecular-cluster theory. Using a discrete variational method with the necessary constraints on molecular-orbital occupation numbers and the potential field, we determine the spin-flip energy and hence the N\'eel temperature TN for NiO which is in excellent agreement with experiment.