Vapor-liquid equilibria in fluids of two-center Lennard-Jones molecules

Journal Article · Wed Dec 14 23:00:00 EST 1988 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j100336a023· OSTI ID:6189006

Gupta, S

Molecular dynamics simulations are performed using 500 molecules for pure fluids of two-center Lennard-Jones (12:6) molecules to obtain thermodynamic results, including the residual Helmholtz free energy, for several isotherms. Thermodynamic results obtained from these simulations are utilized to predict the vapor-liquid equilibria in these fluids. Simulation results have also been used to estimate the critical temperatures and critical densities of these fluids, and these are compared with the existing predictions from three theoretical methods. These comparisons show that the site-site Ornstein-Zernike equation, with the Percus-Yevick approximation, for these fluids overpredicts the critical temperatures, and a nonspherical reference potential based perturbation theory also shows small deviations whereas an approximate form of the zeroth-order Mayer function expansion cluster perturbation theory works well. These three methods predict well the critical densities of these fluids, within the combined uncertainties of the results.

• Research Organization: Louisiana State Univ., Baton Rouge (USA)
• DOE Contract Number: FG05-86ER13632
• OSTI ID: 6189006
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 92:25; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKANES
COMPUTERIZED SIMULATION
DATA
DYNAMICS
ETHANE
FLUIDS
GASES
HYDROCARBONS
INFORMATION
LIQUIDS
MATHEMATICAL MODELS
MECHANICS
NITROGEN COMPOUNDS
NUMERICAL DATA
ORGANIC COMPOUNDS
PERTURBATION THEORY
PHYSICAL PROPERTIES
POTENTIALS
SIMULATION
THEORETICAL DATA
THERMODYNAMIC PROPERTIES
VAPORS