On superexchange in magnetic insulators

The general multielectron theory of superexchange formulated earlier is applied to construct the effective spin-orbital Hamiltonian within the ground crystal states. The symmetry considerations allow one to reduce a great number of dependent exchange parameters to only a few independent ones without any simplifications of the theory. Kinetic approximation reduces it to only two for arbitrary dsup(n)-dsup(n) pair of ions. (author)