add tests

tests/transformations/test_standard_transformations.py

@@ -36,6 +36,7 @@
     SubstitutionTransformation,
     SupercellTransformation,
 )
+from pymatgen.alchemy.transmuters import StandardTransmuter
 from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR
 
 enumlib_present = which("enum.x") and which("makestr.x")
@@ -427,6 +428,43 @@ def test_random_sample(self):
         output = trafo.apply_transformation(struct * [2, 2, 2], return_ranked_list=False)
         assert output.composition.reduced_formula == struct.composition.reduced_formula
 
+    def test_occ_tol_with_supercell(self):
+        """Test occ_tol parameter behavior with supercell structures."""
+        # Create a disordered structure
+        coords = [[0.0, 0.0, 0.0], [0.5, 0.5, 0.5]]
+        lattice = Lattice(
+            [[2.9823991724941643, 0.0, 1.8261928001873466e-16],
+            [4.796063659664723e-16, 2.9823991724941643, 1.8261928001873466e-16],
+            [0.0, 0.0, 2.9823991724941643]]
+        )
+        struct = Structure(lattice, [{"V": 0.75, "Ti": 0.25}, {"V": 0.75, "Ti": 0.25}], coords)
+
+        # Create a 5x5x5 supercell structure
+        supercell = struct * [5, 5, 5]
+
+        # Test 1: Default occ_tol (0.25) should raise error
+        ts_strict = OrderDisorderedStructureTransformation(algo=-1, no_oxi_states=True, occ_tol=0.25)
+        with pytest.raises(ValueError, match="Occupancy fractions not consistent with size of unit cell"):
+            StandardTransmuter.from_structures(
+                [supercell], 
+                transformations=[ts_strict], 
+                extend_collection=3
+            )
+
+        # Test 2: Relaxed occ_tol (0.5) should work
+        ts_relaxed = OrderDisorderedStructureTransformation(algo=-1, no_oxi_states=True, occ_tol=0.5)
+        transmuter = StandardTransmuter.from_structures(
+            [supercell], 
+            transformations=[ts_relaxed], 
+            extend_collection=3
+        )
+
+        # Verify the transformation worked and produced expected composition
+        transformed_structs = transmuter.transformed_structures
+        assert len(transformed_structs) == 3
+        # Check composition matches expected Ti31V94
+        composition = transformed_structs[0].final_structure.composition
+        assert composition.reduced_formula== "Ti31V94"
 
 class TestPrimitiveCellTransformation:
     def test_apply_transformation(self):