Argon

The Lennard-Jones model for argon.

Argon (Ar) has a mass of 39.948 umas. Sadus and Prausnitz have shown that three-body repulsion makes a significant contribution to three-body interactions in the liquid phase (for use of the Axilrod-Teller interaction see ). However, the generic Lennard-Jones model has been frequently used due to its simplicity; some parameters are quoted in the next section. A specific interatomic potential for Ar has been proposed by Aziz .

Thermophysical properties (experimental)

Property	Temperature	Pressure
Triple point	83.8058 K	69 kPa
Critical point	150.87 K	4.898 MPa
Melting point	83.80 K
Boiling point	87.30 K

Lennard-Jones parameters

The Lennard-Jones parameters for liquid argon are listed in the following table:

Authors	$\epsilon /k_{B}$ (K)	$\sigma$ (nm)	Reference
Rowley, Nicholson and Parsonage	119.8	0.3405
Barker, Fisher and Watts	142.095	0.33605
White	125.7	0.3345	parameter set #4

Radial distribution function

Radial distribution function

• J. L. Yarnell, M. J. Katz, R. G. Wenzel and S. H. Koenig "Structure Factor and Radial Distribution Function for Liquid Argon at 85°K", Physical Review A 7 pp. 2130-2144 (1973)

Quantum simulations

• J. R. Melrose and K. Singer "An investigation of supercooled Lennard-Jones argon by quantum mechanical and classical Monte Carlo simulation", Molecular Physics 66 1203-1214 (1989)

References

Related material

• H. C. Longuet-Higgins and B. Widom "A rigid sphere model for the melting of argon", Molecular Physics 8 pp. 549-556 (1964)
• D. Henderson and J. A. Barker "On the solidification of argon", Molecular Physics 14 pp. 587-589 (1968)
• F. Lado "Numerical Calculation of the Density Autocorrelation Function for Liquid Argon", Physical Review A 5 pp. 2238-2244 (1972)