COSMO vs. COSMO-RS 

Continuum solvation models (CSMs) such as PCM or COSMO are widely used in quantum chemistry to approximate the effect of solvents. Find here a line-up of effects in solution and the ability of COSMO-RS and CSMs to incorporate them.

Effects in solution

Relevance

CSM

COSMO-RS

Polarization of solute

high

+

+

Reorientation of solvent molecules

high

--

++

Geometry changes

medium – high

+

+

Conformer equilibrium in different solvents

medium1

--

++

Electrostatic interaction with solvent

high

+

+

Hydrogen bond interaction

very high

--

+

Steric decrease of interactions

medium1

--

-- / o2

Non zero solute concentrations

medium

--

++

Temperature dependence

medium

--

+

Mixtures of solvents

high

--

++

1 Very important for some molecules / properties
2 Partly implemented within the TZVPD-FINE-level