A method to predicate the surface charge density distribution（σ profile) of molecules for COSMO-SAC based on group contribution method was proposed. The original data base to regress the parameters was calculated by Gaussian 03 B3LYP/6-311g（d) models. The group definition methods are identical to those used previously for boiling point estimation. The activity coefficients at infinite dilution and vapor liquid equilibrium of various binary systems were calculated based on the estimated and calculated σ profiles and results were compared with the experimental data stored in Dortmund Data Bank. The results showed that the σ profiles derived from the above proposed methods can be used to calculate the behavior of real mixtures. The limitations of the methods are also discussed.
展开▼
