Investigation of the role of coordination number in the Lennard-Jones-Devonshire theory

The theory of Lennard-Jones-Devonshire (LJD) has been studied for more than six decades by many researchers. Recently, Magee and Wilding have shown that in addition to the critical point originally reported for the 12-6 Lennard-Jones potential, the model exhibits a further critical point. In the present work, the effect of coordination number on the pressure-volume-temperature behavior of systems represented by the LJD-based equation of state was investigated. It was found that by varying the value of coordination number (C), different curves of P*(dimensionless pressure) versus v*(dimensionless volume) can be obtained for a specific T* (reduced temperature). Consequently, improved representations of experimental data can be obtained by taking advantage of this characteristic of the P*-v*-T*-C relationship.