Thermodynamic perturbation theory coefficients for ellipsoidal molecules

Author(s)

de Souza, Nathan Barros ^[1] ; Lopes, Joyce Tavares ^[1] ; Mercier Franco, Luis Fernando ^[1]

Affiliation

^[1] Univ Estadual Campinas, Sch Chem Engn, Av Albert Einstein 500, BR-13083852 Campinas - Brazil

• Document type: Journal article
• Source: Fluid Phase Equilibria; v. 549, DEC 1 2021.
• Web of Science Citations: 0

Abstract

Perturbation theory has been the center of the development of the new generation of equations of state. First- and second-order perturbation theories are very common, but require approximations for obtaining an analytical form. Recently, a new equation of state has been proposed in which the reference fluid is based on the hard Gaussian overlap approach, and the perturbed potential is defined as a spherically symmetric square well. In such an approach, the first- and second-order coefficients were considered the same as the ones applied for a system in which the reference term is spherical. Using Monte Carlo simulations, we investigated the validity of such an approximation by calculating the first- and second-order coefficients of the high-temperature expansion series of the Helmholtz free energy. With our findings, this approximation seems to be quite reasonable for a certain range of anisotropies. We also present a calculation of the perturbed molar Helmholtz free energy using Monte Carlo simulations, which could in principle be used for improving the equation of state. (C) 2021 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 18/02713-8 - Molecular dynamics of confined fluids: equilibrium and transport properties
• Grantee: Luís Fernando Mercier Franco
• Support Opportunities: Research Grants - Young Investigators Grants