Gibbs-Bogoliubov variational scheme calculations for the liquid structure of 3d transition metals

Abstract

The results of calculations of the static structure factor S(q) for liquid 3d transition metals are presented. These have been studied using effective inter-ionic pair potentials proposed by two of the authors (JLB and MS), that combine the empty-core model used to describe the nearly-free-electron band and a d-band contribution deduced via an inverse scattering approach. They have potential wells that are shallower and shifted towards the larger values of r than the corresponding Wills-Harrison potentials used by other authors. The fluid aspects are modelled through a charged hard-sphere reference system optimised via the Gibbs-Bogoliubov variational scheme. The results for S(q) agree reasonably well with the available experimental data. The optimized values found for the hard-sphere diameters reveal that the ions never sample the hard cores, confirming earlier findings on the need to use a soft-core reference system for liquid transition metals.