ELECTRONIC-STRUCTURE AND MAGNETISM IN 4D TRANSITION-METAL CLUSTERS

We analyze the stability of magnetic states obtained within the tight- binding model for cubooctahedral (O-h) and icosahedral (I-h) clusters of early 4d (Y, Zr, Nb, Mo, and Tc) transition metals. Several metasta ble magnetic clusters are identified which suggests the existence of m ultiple magnetic solutions in realistic systems. A bulk-like parabolic behavior is observed for the binding energy of O-h and I-h clusters a s a function of the atomic number along the 4d-series. The charge tran sfer on the central atom changes sign, while the average magnetic mome nts present an oscillatory behavior as a function of the number of d e lectrons in the cluster. Our results are in agreement with other theor etical calculations.