On calculating the magnetic state of nanostructures

We review some of our recent work on first principles calculations of the magnetic structure of surface and bulk nanostructures. The calculations are based on implementation of relativistic density functional theory within state of the art surface embedding and order-N multiple scattering Green’s function methods. First principles spin-dynamics and the constrained local moment approximation are reviewed as they relate to optimization of moment configurations in highly inhomogeneous materials such as surface and bulk nanostructures. Results are present for three prototypical nanostructures – short Co-chains adjacent to a Pt{1 1 1}-surface step-edge, a Cr-trimer on the Au{1 1 1}-surface, and Fe-chains and impurities in Cu – that illustrate the need to treat the underlying electronic interactions on a fully self-consistent basis in which the very different energy scales appropriate to exchange coupling and magneto-crystalline anisotropy are treated on an equal footing.