The Free Solvation Database, FreeSolv(SAMPL), provides experimental and calculated hydration free energy of small molecules in water. The calculated values are derived from alchemical free energy calculations using molecular dynamics simulations. The experimental values are included in the benchmark collection.

The data file contains a csv table, in which columns below are used:
     "iupac" - IUPAC name of the compound
     "smiles" - SMILES representation of the molecular structure
     "expt" - Measured solvation energy (unit: kcal/mol) of the compound, used as label
     "calc" - Calculated solvation energy (unit: kcal/mol) of the compound

Reference:
Mobley, David L., and J. Peter Guthrie. "FreeSolv: a database of experimental and calculated hydration free energies, with input files." Journal of computer-aided molecular design 28.7 (2014): 711-720.