  We present a newly developed scheme for atomic relaxations of magnetic
supported clusters. Our approach is based on the full potential
Korringa-Kohn-Rostoker Green's function method and the second moment
tight-binding approximation for many-body potentials. We demonstrate that only
a few iterations in ab initio calculations are necessary to find an equilibrium
structure of supported clusters. As an example, we present our results for
small Co clusters on Cu(001). Changes in electronic and magnetic states of
clusters due to atomic relaxations are revealed.
