To calculate the solvation (including self-solvation) free energies, single point energy calculations were performed in vacuum and in the SM12, SM8 and SMD universal solvent models for each solvent of interest at the M06-2X/6-31G(d) level of theory/basis set using QChem 5.1.2. Using QChem 5.1.2, the calculation of the solvation free energy is handled completely internally by the software. We emphasize that we used the same conformation for the solute in the ideal gas (vacuum) and solution phases, consistent with the SM12, SM8, and SMD parameterizations . It is possible to consider different configurations for the two phases, and it is possible to incorporate multiple configurations into the calculation of the solvation free energy which may be important for some systems . However, this was not pursued here for simplicity.