Self-consistent tight-binding method for the prediction of magnetic spin structures in solids: Application to MnF2 and MnO2 - art. no. 024413

We introduce a self-consistent tight-binding approach to the modeling and p rediction of magnetic structure in solids. The method is similar to a charg e self-consistent tight-binding method which we introduced earlier, but her e we add information concerning the dependence of the ion energy on the tot al ion spin in the on-site matrix elements of the tight-binding Hamiltonian . We self-consistently determine both spins and charges of the ions during calculation. We illustrate with studies of MnF2 and the rutile form of MnO2 . In the first case we find without adjustment that the well-known two subl attice spin structure is predicted. In the second case we find that a disor dered spin phase is predicted, contrary to experimental evidence, but a sma ll adjustment of the parametrization yields the spiral spin structure sugge sted by experiments.