def METHOD_NAME(self):
    element_a, element_b = 'Al', 'Fe'
    structure = self.compound.D03(element_a, element_b)
    symbols = structure.get_chemical_symbols()
    neigh = structure.get_neighbors(num_neighbors=8)
    a_neighbors = neigh.indices[symbols == element_a]
    self.assertTrue(np.all(symbols[a_neighbors] == element_b), msg="A-type should only have B-type neighbors.")
    b_neighbors = neigh.indices[symbols == element_b]
    sorted_vals, counts = np.unique(np.mean(symbols[b_neighbors] == 'Al', axis=1), return_counts=True)
    self.assertAlmostEqual(0, sorted_vals[0], msg="Shared sub-lattice has no A-type neighbors.")
    self.assertAlmostEqual(0.5, sorted_vals[1], msg="B-type sub-lattice has half A-type neighbors.")
    self.assertEqual(4, counts[0], msg="Shared sub-lattice should be only 1/4 of atoms.")
    self.assertEqual(8, counts[1], msg="Pure-B sub-lattice should be 1/2 of atoms.")