Liquid structure of titanium and vanadium; VMHNC calculations

The first successful calculations for the liquid structure S(q) of the early 3d transition metals are presented; they use effective pair interionic potentials and an integral equation theory of liquids. The effective pair potentials are obtained from a local form that assumes the superposition of the nearly free electron band, described by the empty-core model, and the d-band contribution, which is calculated by using an inverse scattering approach. The liquid state theory used in the calculations is the variational modified hypernetted chain (VMHNC) approximation. The agreement between the calculated S(q) and the available X-ray diffraction data for vanadium is reasonably good, but for titanium is only fair.