Structural changes of simple expanded liquids at high temperatures

Abstract

The Fisher-Widom (FW) line [1] separates the phase diagram into regions with different asymptotic behavior of the pair correlation function. The FW line can be obtained analytically if one gets exact expression for the pair correlation function, but it can not be done from experimental data, because the structure factor is measured for the limited range of wave vectors. We have found out that the approximate position of the FW line can be found from the local atomic arrangement in the Lennard-Jones model. We use this circumstance to analyse the structure of expanded liquid metals (Hg, Cs, Rb). The universal systems' behavior has been revealed, and it can be suggested that the FW line corresponds to the region where atomic and electronic properties change considerably. © 2008 IOP Publishing Ltd.