Thermodynamics of a long-range triangle-well fluid

Abstract

The long-range triangle-well fluid has been studied using three different approaches: firstly, by an analytical equation of state obtained by a perturbation theory, secondly via a self-consistent integral equation theory, the so-called self-consistent Ornstein-Zernike approach (SCOZA) which is presently one of the most accurate liquidstate theories, and finally by Monte Carlo simulations. We present vapour-liquid phase diagrams and thermodynamic properties such as the internal energy and the pressure as a function of the density at different temperatures and for several values of the potential range. We assess the accuracy of the theoretical approaches by comparison with Monte Carlo simulations: the SCOZA method accurately predicts the thermodynamics of these systems and the first-order perturbation theory reproduces the overall thermodynamic behaviour for ranges greater than two molecular diameters except that it overestimates the critical point. The simplicity of the equation of state and the fact that it is analytical in the potential range makes it a good candidate to be used for calculating other thermodynamic properties and as an ingredient in more complex theoretical approaches.

Thermodynamics and phase behavior of a triangle-well model and density-dependent variety

“…Figure 12 also presents the same comparison but at a longer potential range of ␦ = 2 and between the fifth-order TPT, the SCOZA, 27 and a LR-TW EoS reported in Ref. 25. As expected, the fifth-order TPT exceeds the LR-TW EoS obviously.…”

Which Shape Characteristics of the Intermolecular Interaction of Liquid Water Determine Its Compressibility?

“…We obtain the thermodynamic properties of the models by using the SCOZA [33][34][35][36][37][38][39][40]. We express the physical quantities by the same symbols, and the numerical computations are performed as described in Yasutomi [39,40].…”

“…The SCOZA is known to describe the overall thermodynamics of liquids very well and provides a remarkably accurate critical point and coexistence curve. This scheme is entirely self-contained, which means that no supplementary thermodynamic or other input is necessary [33][34][35][36][37][38][39][40].…”

A self-consistent Ornstein–Zernike approximation for a fluid with a screened power series interaction

“…So far, the SCOZA scheme has been applied to Yukawa potential, Sogami-Ise potential, square-well potential, and triangle-well potential, and many fruitful results have been obtained ͑see Pini et al, 6 Schöll-Paschinger, 7,8 Betancourt-Cárdenas et al, 9 and references quoted therein͒. The excess internal energy u per unit volume is given by the integral of the interaction weighted by the radial distribution function, the closure relations ͑3͒ and ͑4͒.…”