Based on the results of computer simulation of transport coefficients in a Lennard-Jones fluid, it has been shown that in ($p$,$T)$ coordinates, lines of constant values of coefficients of self-diffusion $D$ and excess shear viscosity $\Delta \eta$ extended into the region of superheated liquid and supersaturated vapor have an envelope. Each of the ensembles of such lines is divided into two parts by a critical isoline, where the conditions $\varphi ={\varphi }_c=\mathrm{const}$ $(\varphi =D,\Delta \eta )$ are fulfilled. One part of this ensemble has as an envelope the branch of the spinodal that refers to superheated liquid; the other part has the branch of the spinodal of supersaturated vapor. The critical point of liquid-vapor equilibrium is the cusp of the spinodal, at which the critical isolines have a common tangent line with the spinodal and the binodal. Thus, at the approach to the spinodal, the relations ${(\partial D/\partial p)}_T\to \infty$ and ${(\partial \Delta \eta /\partial p)}_T\to \infty$ hold.

• Received 29 May 2012

DOI:https://doi.org/10.1103/PhysRevE.86.021201