The COSMO and COSMO‐RS solvation models

The conductor‐like screening model COSMO, a variant of the dielectric continuum solvation models, has become very popular due to its algorithmic simplicity, numerical stability, and its great insensitivity with respect to outlying charge errors. The advanced model COSMO‐RS, i.e., COSMO for realistic solvation, is a statistical thermodynamics theory based on COSMO polarization charge densities, which overcomes many of the limitations and theoretical shortcomings of dielectric continuum models. Due to its ability to treat mixtures at variable temperatures, it has become very popular in chemical engineering and in wide areas of physical and medicinal chemistry. COSMO‐RS currently may be considered as the most accurate model for the prediction of solvation energies. This article provides a short description of the basic concepts of both the models, of the differences with other solvation models and of their application areas. Finally, direct COSMO‐RS, a recent direct integration of the COSMO‐RS concept into quantum chemical calculations, is briefly described.