EFFECTIVE PAIR POTENTIALS AND STRUCTURES OF LIQUID RARE-EARTH-METALS NEAR THE MELTING-POINT

The simple-metal theory may describe the structures of liquid rare earth metals when the pseudopotential parameters are properly selected. Such point has been tested for liquid La, Ce, Pr and Nd near the melting point using the Percus-Yevick integral equation and the Ashcroft empty-core form for the pseudopotential. The core radius was uniquely determined by the density of liquid and the effective valence Z(eff) was estimated from the value of the plasma parameter which reasonably explains the structural features and some thermodynamic properties coupled with the one-component plasma (OCP) model. The validity of the value of Z(eff) has been supported by the Gibbs-Bogoliubov variational method using the OCP reference system.