MAGNETIC 3D IMPURITIES IN NB AND MO

We calculate the electronic structure of 3d impurities in niobium and molybdenum. Our calculations rely on the local density approximation of density functional theory. Assuming a muffin-tin description of the atomic potentials, the impurity potential and the ones of the nearest neighbors are calculated self-consistently while the embedding of this perturbed cluster into the host is described correctly by the KKR-Green function method. In molybdenum we find rather large local moments for Mn, Fe and Co impurities. Surprisingly, in niobium we also obtain similar large moments for Cr, Mn and Fe impurities. Whereas the results for 3d impurities in Mo agree very well with the experimental data, a serious disagreement exists for the niobium case which is not understood.