Abstract
Equations of state based on intermolecular potentials are often developed about the Lennard-Jones (LJ) potential. Many of such EOS have been proposed in the past. In this work, 20 LJ EOS were examined regarding their performance on Brown’s characteristic curves and characteristic state points. Brown’s characteristic curves are directly related to the virial coefficients at specific state points, which can be computed exactly from the intermolecular potential. Therefore, also the second and third virial coefficient of the LJ fluid were investigated. This approach allows a comparison of available LJ EOS at extreme conditions. Physically based, empirical, and semi-theoretical LJ EOS were examined. Most investigated LJ EOS exhibit some unphysical artifacts.
Highlights
The Lennard-Jones (12,6) potential [1, 2] has been extensively used since the early days of computer simulation [3,4,5,6] for the modeling of repulsive and dispersive interactions of simple fluids
The second and third virial coefficient computed from the 20 considered LJ equations of state (EOS) are compared in Fig. 1 with exact data obtained from statistical mechanics [81] published in the literature [7, 29, 60, 82,83,84]
The numeric values for the second and third virial coefficient computed from the 20 considered LJ EOS are reported in the electronic Supplementary Material
Summary
The Lennard-Jones (12,6) potential [1, 2] has been extensively used since the early days of computer simulation [3,4,5,6] for the modeling of repulsive and dispersive interactions of simple fluids. As Brown’s characteristic curves are directly related to virial coefficients, the second and third virial coefficient are studied This comparison is of particular interest, since the virial coefficients of the LJ fluid can be computed exactly from their definitions in statistical mechanics, while reference data obtained from computer simulations are subject to errors and uncertainties [7, 71, 72]. Brown proposed the characteristic curves for the assessment of equations of state for a fluid with repulsive and dispersive interactions [70].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
