Structure and phase behavior of square-well dimer fluids

A Born–Green–Yvon integral equation approach is used to study the structure and phase behavior of a fluid of fused square-well-sphere dimers. We compute site–site distribution functions for dimers with bond lengths of L50.6s , 0.8s, and 1.0s ~where s is the hard-sphere diameter! and square-well diameters ranging from l51.25s to 2.0s over a wide range of temperature and density, and make comparisons with both exact and simulation results. For the tangent square-well dimer fluid having l51.5 we obtain a binodal and spinodal via the energy route, and compare our results with Monte Carlo data. The computational intensity of this approach has lead us to search for an alternate route to information about phase behavior, and so we also show how our compressibility results may be used in order to construct approximate spinodal curves. © 2001 American Institute of Physics. @DOI: 10.1063/1.1338981#