Extending Wertheim's perturbation theory to the solid phase: The freezing of the pearl-necklace model

An extension of Wertheim's first order perturbation theory [M. S. Wertheim, J. Chem. Phys. 87, 7323 (1987)] for chain molecules in the solid phase is proposed. In particular the solid phase of a model of freely jointed chains of tangent hard spheres has been considered. The equation of state and fre e energies from theory are compared with simulation results obtained previo usly by Malanoski and Monson [A. P. Malanoski and P. A. Monson, J. Chem. Ph ys. 107, 6899 (1997)]or chains with up to eight monomer units. The agreemen t between theory and simulation is good for the densities close to the melt ing, and deteriorates for densities close to close-packing. We also evaluat ed theoretically the fluid-solid equilibrium of the pearl-necklace model an d compare with simulation results. The theory reproduces reasonably well th e trends observed in the simulation results. (C) 2001 American Institute of Physics.