The thermodynamics of heteronuclear molecules formed from bonded square-well (BSW) segments using the SAFT-VR approach

We broaden the scope of the statistical associating fluid theory for potent ials of variable attractive range (SAFT-VR) to treat heteronuclear chain mo lecules formed from bonded square-well (BSW) segments. The ideas of the bon ded hard sphere (BHS) treatment for distributed-site models composed of har d-sphere segments are applied to square-well sites with the SAFT-VR approac h. The results of isothermal-isobaric Monte Carlo simulations are reported for heteronuclear square-well diatomics with different sets of energy and r ange parameters. The SAFT-VR approach provides an excellent description of the equation of state of the diatomic systems for a wide range of densities . The goal of the work is to provide a rigorous treatment of distributed-si te models of fluids, and to establish a framework for a group contribution approach with SAFT-VR.