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The magnetic properties and electronic structure of bcc Fe-Co alloys and multilayers are investigated with the first-principles molecular cluster discrete variational method. The density of states and the contact interactions are obtained for the central atom of each cluster. Besides the local magnetic moment and the isomer shift the occupancies of 3d, 4s, and 4 p shells are investigated when Co atoms are introduced in the immediate vicinity of iron sites. The calculations indicate a varying magnetic moment for Fe atoms and a constant value for Co atoms which is in agreement with experiments. For the superstructures, our results indicate a strong dependence of the local moment, contact field, and isomer shift for Fe atoms with the thick of iron layers. The internal field increases for thicker Fe layers while the local moment decreases which is also in accordance with experimental predictions.

The first-principles discrete variational method is employed to investigate the electronic structure and local magnetic properties of disordered Fe-V alloys. The spin-polarized case is considered in the formalism of the local-spin-density approximation, with the exchange-correlation term of von Barth-Hedin. The effect on the local magnetic properties of adding V atoms in the immediate neighborhood of iron atoms is investigated. The partial density of states, hyperfine field (H c ), magnetic moment (), and isomer shift are obtained for the central atom of the cluster. For the impurity V atom in the bcc iron host the calculated values for H c and are Ϫ203 kG and Ϫ0.86 B , respectively. The isolated Fe atom in a bcc vanadium host exhibits a collapsed moment and acts as a receptor for electrons. In ordered alloys the calculations indicate also a vanishing moment at iron sites. ͓S0163-1829͑98͒05901-3͔