added unittest to compare the radical and saturated

Another uniitest is added to compare the radical and its saturated
species solvation free energy in water. The test makes sure the two
solvation energies are different.

rmgpy/data/solvationTest.py

@@ -195,9 +195,19 @@ def test_radical_and_lone_pair_generation(self):
 
     def test_radical_solute_group(self):
         """Test that the existing radical group is found for the radical species when using group additivity"""
-        species = Species(molecule=[Molecule(smiles='[OH]')])
-        solute_data = self.database.get_solute_data_from_groups(species)
-        self.assertTrue('radical' in solute_data.comment)
+        # First check whether the radical group is found for the radical species
+        rad_species = Species(smiles='[OH]')
+        rad_solute_data = self.database.get_solute_data_from_groups(rad_species)
+        self.assertTrue('radical' in rad_solute_data.comment)
+        # Then check that the radical and its saturated species give different solvation free energies
+        saturated_struct = rad_species.molecule[0].copy(deep=True)
+        saturated_struct.saturate_radicals()
+        sat_species = Species(molecule=[saturated_struct])
+        sat_solute_data = self.database.get_solute_data_from_groups(sat_species)
+        solvent_data = self.database.get_solvent_data('water')
+        rad_solvation_correction = self.database.get_solvation_correction(rad_solute_data, solvent_data)
+        sat_solvation_correction = self.database.get_solvation_correction(sat_solute_data, solvent_data)
+        self.assertNotAlmostEqual(rad_solvation_correction.gibbs / 1000, sat_solvation_correction.gibbs / 1000)
 
     def test_correction_generation(self):
         """Test we can estimate solvation thermochemistry."""