Multidensity integral equation theory for a sticky hard sphere-hard sphereheteronuclear dimer fluid: Thermodynamic and structural properties

The thermodynamic and structural properties of a sticky hard sphere-hard sp here heteronuclear dimer fluid was studied using the multidensity Ornstein- Zernike integral equation theory. In this formalism, a monodisperse system of the heteronuclear dimer was modeled as an equal molar binary mixture of associating sticky hard sphere and hard sphere particles in the complete as sociation limit. A general analytical solution to the model was obtained wi thin the Percus-Yevick and polymer Percus-Yevick approximations for any deg ree of association including the complete association limit. Explicit analy tical expressions for the contact values of correlation functions were obta ined. Further, correlation functions beyond the hard core region were also calculated. The Helmholtz energy and pressure of the heteronuclear dimer ar e obtained via the energy route. The critical temperature, critical density , and phase coexistence of the fluid are also obtained. (C) 2001 American I nstitute of Physics.