Fix CH ground-state representation

rmgpy/molecule/moleculeTest.py

@@ -1042,12 +1042,12 @@ def testPickle(self):
 
     def testRadicalCH(self):
         """
-        Test that the species [CH] has three radical electrons and a spin multiplicity of 4.
+        Test that the species [CH] has one radical electrons and a spin multiplicity of 2.
         """
         molecule = Molecule().fromSMILES('[CH]')
-        self.assertEqual(molecule.atoms[0].radicalElectrons, 3)
-        self.assertEqual(molecule.multiplicity, 4)
-        self.assertEqual(molecule.getRadicalCount(), 3)
+        self.assertEqual(molecule.atoms[0].radicalElectrons, 1)
+        self.assertEqual(molecule.multiplicity, 2)
+        self.assertEqual(molecule.getRadicalCount(), 1)
 
     def testRadicalCH2(self):
         """

rmgpy/molecule/parser.py

@@ -59,6 +59,12 @@
             multiplicity 3
             1 C u2 p1 c0
             """,
+    '[CH]':  # We'd return the quartet without this
+            """
+            multiplicity 2
+            1 C u1 p1 c0 {2,S}
+            2 H u0 p0 c0 {1,S}
+            """,
 
 }     
 

rmgpy/molecule/parserTest.py

@@ -278,11 +278,9 @@ def test_fromSMILES(self):
         # of methylidyne exists as a mixture of electronic states even at
         # room temperature, giving rise to complex reactions.
         #
-        # Should we make the doublet? For now, this is a regression test,
-        # because we currently make the quartet.
         adjlist = '''
-        multiplicity 4
-        1 C u3 p0 c0 {2,S}
+        multiplicity 2
+        1 C u1 p1 c0 {2,S}
         2 H u0 p0 c0 {1,S}
         '''
         smiles = '[CH]'