The Similarity Relations Set on the Basis of Symmetrization of the Liquid–Vapor Phase Diagram

Abstract

An approach to symmetrize the liquid-vapor phase coexistence curve is proposed. It is based on the introduction of the lattice-like density x = ρ1/(ρ1 + ρ2), where ρ1 and ρ2 are the densities along the liquid-gas binodal. The global symmetrical phase diagram is created using experimental and simulation data for the real substances and models (noble gases, polyatomic molecules, organic substances and two metals, van der Waals system, Lennard-Jones system). The pressure and the temperature along the binodal are shown to satisfy some new similarity relations.

Ideality contours and thermodynamic regularities in supercritical molecular fluids

“…The straightness of the lines, in particular of the Z line holds well with an AARD of 0.5 %. The EWL results for CO 2 are in very good agreement with those extrapolated from the experimental data on low temperature liquids [24]. The EWL T c : T B ratio (0.44) and ρ c : ρ B ratio (0.26) are close to those (0.42 and 0.26) from [24].…”

“…The EWL results for CO 2 are in very good agreement with those extrapolated from the experimental data on low temperature liquids [24]. The EWL T c : T B ratio (0.44) and ρ c : ρ B ratio (0.26) are close to those (0.42 and 0.26) from [24]. We also observe that the straightness of the H line also holds, with a very low AARD for the H line of 0.8 %.…”

“…Recent work has shown that several thermodynamic regularities established on the van der Waals (vdW) equation can be extended to real substances [13]. First, the contour Z = P/ρT = 1 (where Z is the compressibility factor, P the pressure, ρ the number density and T the temperature) follows a straight line in the density-temperature plane for the vdW equation, for model systems [20], water [21] and several other compounds [22,23,24]. Second, the H contour (curve of ideal enthalpy) is a straight line for the vdW equation [12] and for the LJ fluid [13].…”

Evaluation of the grand-canonical partition function using Expanded Wang-Landau simulations. V. Impact of an electric field on the thermodynamic properties and ideality contours of water

“…In particular, in the supercritical region of the phase diagram, we focus on analyzing the effect of the field on the ideality contours [29][30][31][32][33][34][35] , known as the Zeno line and the curve of ideal enthalpy, to establish a correspondence between the results obtained for different fields. These ideality contours have recently emerged as a new way to bridge the gap in our understanding of supercritical fluids [36][37][38][39] and have paved the way for the development of new similarity laws 30 and maps of the supercritical region of the phase diagram 40,41 . This paper is organized as follows.…”

Atomistic modeling of the critical region of copper using a liquid-vapor coexistence curve

“…Due to the difficulty of conducting experiments at high temperatures, the critical point and binodal parameters were obtained only for a small amount of substances, which include alkali metals and mercury, which have relatively low temperature characteristics [6][7][8][9][10][11]. For other materials, there are only theoretical estimates within the framework of various models, among which phenomenological methods [12][13][14][15][16][17][18][19][20][21][22][23][24] and atomistic modeling methods [25][26][27][28][29][30][31] stand out.…”