Conduction electrons in magnetic metals

The conduction electrons in magnetic metals are sometimes themselves responsible for the magnetism, as in the 3d transition metals, and sometimes are magnetic intermediaries, as in the rare earths. In both cases the calculated magnitude of the exchange interactions is now in good agreement with experiment. The effect of magnetism upon the crystal structure of tie 3d transition metals is reviewed. In the rare earths the manner in which the conduction electrons mediate the interactions between the 4f states is examined by using constrained calculations. The actinides present a more complex problem since there are large orbital contributions to the magnetic moments which are not, as in the rare earths, determined by Russel-Saunders coupling and the Wigner-Eckart theorem.