Properties of Pure Globular Substances

A further remark concerns the reduced form of the interaction law. Introducing the dimensionless quantities 

All variables are now dimensionless. Calculation of the partition function and the equation of state shows that the reduced equation of state is of the form 

The second virial coefficient can be readily calculated from the general interaction law (13.5.10) if we retain only central terms. Here we only give the principal features of the result of the calculation (Balescu [1956]). 

When one compares the second virial coefficients of a reference substance (having four atoms localized at the same point) and of a real tetrahe c globular substance, (idealized as an assembly of the same four atoms localized at the summits of a regular tetrahedron), one ob-soves two effects  

One can devise a method for deternmung the parameters e and r (rdative to the boimd atoms) from experimental data on the second virial coefficient (Balescu [1956]). A computation of these para-noeters for the F-atom in CF4 has own that r = but sp = 0.5 

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