Abstract
The Barker—Henderson perturbation theory for uniform fluids is extended to include nonuniform fluids. The surface tension for a Lennard‐Jones fluid is calculated by minimizing the free energy in the surface layer. Comparison with the corresponding experimentally obtained values of surface tension for argon shows that excellent agreement is obtained in the case of a Lennard‐Jones 12–6 fluid with values of the potential parameters determined from the second virial coefficient.