Intermolecular potentials and van der Waals radii

A widely used energy function V that describes intermolecular interaction as a function of intermolecular separation r is the Lennard-Jones 12-6 potential  

The resulting potential energy curve is shown in Fig. 4.4.1 in which re is the equilibrium distance. 

Some values for the parameters e (usually given as s/k, where k is Boltzmann s constant) and 8 are given in Table 4.4.3. For simple and slightly polar substances, e and S3 are approximately proportional to the critical temperature 7c and the critical volume Vc, respectively. 

Crystal structure data show that intermolecular nonbonded distances between pairs of atoms vary over a very narrow range. In the absence of hydrogen 

Mingos, Essential Trends in Inorganic Chemistry, Oxford University Press, Oxford, 1998. 

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