The Influence of low density behaviour of state equation on lattice inverted pair potential for lead

A pair potential for lead (Pb) is extracted from the ab-initio energy-volume data using the lattice inversion procedure of Carlsson and co-workers [Phil. Mag. 41 (1980), p. 241]. Because of a limited accuracy of the ab-initio techniques, we extrapolate the energy-volume data for low-density systems with suitable analytical tail functions. We discuss the dependence of the molecular dynamics (MD) simulation structural results and the elastic modules on the choice of the cohesive energy tail function. The MD-simulated radial distribution functions (RDFs), obtained for several energy tails, in several temperatures are discussed.