Abstract
We discuss an extension of the locally self-consistent Green's function method (LSGF) to the case of large magnetic systems with arbitrary orientations of local spin moments. The LSGF method is an order-N, O(N), method for calculation of the electronic structure of systems with an arbitrary distribution of atoms of different kinds on an underlying crystal lattice. The order-N scaling is achieved by associating each atom in the system with its so-called local interaction zone (LIZ). Inside each LIZ the multiple scattering problem is solved exactly. The accuracy of the LSGF calculations is controlled by the size of the LIZ, and its minimal size is ensured by embedding the LIZ into a self-consistent mean-field CPA-like effective medium. We show how this effective medium can be constructed for an alloy with non-collinear spins. Our technique is demonstrated by calculating the ground-state magnetic structure of bcc Fe.