Shielded attractive shell model again: resummed thermodynamic perturbation theory for central force potential.

ABSTRACT

The approach developed earlier to describe the dimerizing shielded attractive shell (SAS) primitive model of chemical association due to Cummings and Stell is generalized and extended to include a description of a polymerizing SAS model. Our extension is based on the combination of the resummed thermodynamic perturbation theory for central force (RTPT-CF) associating potential and self consistent scheme, which takes into account the changes in the system free volume due to association. Theoretical results for thermodynamical properties of the model at different bonding length, density and temperature are compared against newly generated computer simulation results. The theory gives very accurate predictions for the model with bonding length L (*) from the range 0 < L (*) < 0.6 at all values of the density and temperature studied, including the limit of infinitely large temperature.