Added (failing) radical detection test to unittest/moleculeTest.py

When reading in from the smiles '[CH]' the carbon ends up with a radicalElectrons
count of 0 instead of 3. Strangely, [CH2] and [CH3] work fine.
This causes problems in data/thermo.py when trying to find the thermo for [CH].

Author: rwest

rmgpy/data/thermo.py

@@ -582,7 +582,7 @@ def getThermoDataFromGroups(self, molecule):
 
         thermoData = None
 
-        if sum([atom.radicalElectrons for atom in molecule.atoms]) > 0:
+        if sum([atom.radicalElectrons for atom in molecule.atoms]) > 0: # radical species
 
             # Make a copy of the structure so we don't change the original
             saturatedStruct = molecule.copy(deep=True)
@@ -646,7 +646,7 @@ def getThermoDataFromGroups(self, molecule):
 
             # Correct the entropy for the symmetry number
 
-        else:
+        else: # non-radical species
             # Generate estimate of thermodynamics
             for atom in molecule.atoms:
                 # Iterate over heavy (non-hydrogen) atoms

unittest/moleculeTest.py

@@ -856,7 +856,22 @@ def testPickle(self):
         self.assertEqual(molecule0.getFormula(), molecule.getFormula())
         self.assertTrue(molecule0.isIsomorphic(molecule))
         self.assertTrue(molecule.isIsomorphic(molecule0))
-        
+
+    def testRadicalCH(self):
+        """
+        Test that the species [CH] has three radical electrons and a spin multiplicity of 4.
+        """
+        molecule = Molecule().fromSMILES('[CH]')
+        self.assertEqual(molecule.atoms[0].radicalElectrons, 3)
+        self.assertEqual(molecule.atoms[0].spinMultiplicity, 4)
+
+    def testRadicalCH2(self):
+        """
+        Test that the species [CH2] has two radical electrons and a spin multiplicity of 3.
+        """
+        molecule = Molecule().fromSMILES('[CH2]')
+        self.assertEqual(molecule.atoms[0].radicalElectrons, 2)
+        self.assertEqual(molecule.atoms[0].spinMultiplicity, 3)
 ################################################################################
 
 class TestMoleculeSymmetry(unittest.TestCase):