Hi, I have several questions regarding COSMOtherm. Any help is greatly appreciated.

1. Does anyone know whether or not the chemical potential of a compound given by COSMOtherm is the standard chemical potential? The user manual says that it is "the standard chemical potential minus RTln(x)". On the other hand, Andreas Klamt's review articles in Wiley in 2011 and 2017 state that the RTln(x) term is already included. Which one is correct?

2. At chemical equilibrium, the Gibbs' free energy of reaction is zero. But COSMOtherm calculates the equilibrium constant using what it calls the Gibbs' free energy of reaction. Is it actually the standard Gibbs' free energy of reaction and was just not stated explicitly?

3. At chemical equilibrium, we also have the sum of the product of chemical potentials and stoichiometric coefficients to be zero. From this relationship, we get that the sum of the product of standard chemical potentials and stoichiometric coefficients is equal to RTlnK, where K is the equilibrium constant. When I assumed that the chemical potential given by COSMOtherm is indeed the standard chemical potential and found the equilibrium constant using them, it did not match the equilibrium constant obtained from the Gibbs' free energy of reaction (from point 2 above). Then I added RTln(x) to the chemical potentials and used them to calculate the equilibrium constant, this method too did not match he equilibrium constant obtained from the Gibbs' free energy of reaction. So now I am a bit confused as to what the COSMOtherm "chemical potential" actually is.

4. On the flip side, the results of logP and liquid extraction modules conform with the idea that the chemical potential given by COSMOtherm is the standard chemical potential. LogP module calculates the partition constant from the difference in COSMOtherm's chemical potential of a compound between two liquid phases. Liquid extraction module provides (from iterative calculations) the final partition equilibrium compositions and chemical potentials, and it also calculates the partition constant from the difference in COSMOtherm's chemical potential of a compound between two liquid phases. I also added RTln(x) terms to the COSMOtherm's chemical potential values from liquid extraction calculation and the resulting chemical potentials of the compounds are equal in both phases as they should be at phase equilibrium. This implies that the chemical potential of a compound given in COSMOtherm is the standard chemical potential and adding the entropic term RTln(x) gives the chemical potential of a compound in that mixture. But I am not sure why this relationship does not hold for chemical equilibrium calculations.