def test_quantum_number_S_is_None(self):
        # Setup
        Job = InitJob("test_data/JobDef_scase.json")

        # Fake
        def fake_magnetic_correlation(*args):
            return -1
        Job.Electron.magnetic_correlation = fake_magnetic_correlation

        # Action
        S = Job.Electron.quantum_number_S(Job)

        # Result
        assert S is None