Improved angular convergence in noncollinear magnetic orders calculations

The method we use for determining the noncollinear orders in metallic superlattices is presented. The electronic structure is obtained within a semi-empirical tight binding framework and the real space recursion technique which allows to study nonsymmetric systems. We focus our attention on the iterative procedure for reaching the angular self-consistency which is extremely slow to converge. We show that the usual mixing scheme is unsuited (because the output angle is directly equal to the next input) and we give an example of possible speed increase by extrapolating the angles resulting from mixing over a few iterations. Copyright (C) 1998 Elsevier Science B.V.