Values of the two-body interaction coefficients C6 and d4 between like species, as well as the three-body term γ3, are obtained from point charge model formulae. Lewis set results may be compared with atomically centered wave-function values as well as results obtained using an experimental point charge model. Generally results are in good agreement with experiment and when theoretical values differ wildly from experiment they may be normalized using theoretical and experimental static polarizability values. © 1979 Springer-Verlag.