
168 Perturbation Theories for Fluids and Solids
With this modification, the results for the solid come in close agreement with sim-
ulations and also considerably improve for the fluid, although in the latter some
deviation from the simulation data remains for large values of (see Figure 6.9).
6.8.5 LENNARD–JONES FLUID
Barker and Henderson (1976) showed that the second-order perturbation theory with
F
1
and F
2
determined from computer simulation through Equations 6.29 and 6.30,
respectively, provides very satisfactory results for the free energy and the EOS of LJ
fluids at moderate temperatures.
The second-order BH perturbation theory, in either the