Table 1:
Hydration free energies, chemical potentials and octanol-water partition coefficients for all octanol parameters were calculated and compared with experimental values.
| Parametrization | ΔGw (kcal/mol) | Δa | μb (kcal/mol) | Δa | log Pow | Δa |
|---|---|---|---|---|---|---|
| GAFF | −2.62(5) | 1.47(60) | −7.63(16) | 0.50(16) | 3.65(12) | 0.73(15) |
| OPLS-AA | −3.26(5) | 0.83(60) | −8.59(16) | −0.46(16) | 3.89(13) | 0.97(16) |
| CGenFF | −3.82(5) | 0.27(60) | −8.98(19) | −0.85(19) | 3.76(15) | 0.84(17) |
| Expc | −4.09(60) | −8.13 | 2.92(9) |
The difference Δ (Eq. 8a) between experimental and computed hydration free energies, chemical potentials and octanol-water partition coefficients is shown for each octanol parametrization. The standard error of the mean in the last significant digits is given in parentheses (Eq. 8b).
The chemical potential of octanol μ is the transfer free energy of an octanol molecule from vacuum to the pure octanol solvent ΔGo.
Experimental log Powvalues were retrieved from REAXYS (https://www.reaxys.com). Multiple values were averaged and errors were taken as the standard deviation of the mean. The experimental octanol chemical potential μ (no reported uncertainty) and hydration free energy ΔGw were retrieved from the Minnesota Solvation Database (https://comp.chem.umn.edu/mnsol/); the latter agrees with the value from the FreeSolv database (DOI 10.5281/zenodo.1161245).