The calculation of surface tension for simple liquids

The authors calculate surface tension using the Kirkwood-Buff theory, assuming a smooth variation of density between liquid and vapour (in contrast to the Fowler theory, where the density changes abruptly), and approximating the radial distribution function by its liquid value throughout the transition zone. Comparison with experiment enables one to estimate the thickness of the interface, for which values in fair agreement with those given by other theories are obtained.