Publication: Pair Correlation Function and Self-Diffusion Coefficient in the Modified Free Volume Theory of Diffusion

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Title	Pair Correlation Function and Self-Diffusion Coefficient in the Modified Free Volume Theory of Diffusion
Authors/Editors*	Rozita Laghaei, Afshin Eskandari Nasrabad, and Byung Chan Eu
Where published*	Journal of Physical Chemistry B
How published*	Journal
Year*	2005
Volume	0
Number	0
Pages
Publisher	xxxxx
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Abstract	In this paper we apply the MatteoliMansoori empirical formula for the pair correlation function of simple fluids obeying the Lennard-Jones potential to calculate reduced self-diffusion coefficients. The self-diffusion coefficent is computed as functions of temperature and density by using the modified free volume theory of diffusion. We show that the formula yields sufficiently accurate self-diffusion coefficients in the supercritical regime, provided that the minimum free volume activating diffusion is estimated with the classical turning point of binary collision at the mean relative kinetic energy 3kBT /2, where kB is the Boltzmann constant and T is the temperature. In the subcritical regime the empirical formula yields qualitatively correct, but lower values for the self-diffusion coefficients compared with computer simulation values. However, with a slightly modified critical free volume the results can be made quite acceptable.