An intermolecular pair potential energy function for methane

A numerical spherically averaged intermolecular pair potential energy function is presented which describes the interactions of methane molecules. The function incorporates accurate estimates of the long-range dispersion force coefficients, and closely reproduces shear viscosity and second virial coefficient data over a wide temperature range. Agreement with other experimental data which is generally satisfactory is also discussed. The potential is shown to be superior to a large number of analytical potentials previously proposed for this gas.