def METHOD_NAME(self):
    a_type = 'Mg'
    b_type = 'Cu'
    c14 = self.compound.C14(a_type, b_type)
    self.assertEqual(len(c14), 12, "Wrong number of atoms in C14 structure.")
    self.assertEqual(c14.get_chemical_formula(), "Cu8Mg4", "Wrong chemical formula.")