Adding a test for class RandomStructureTransformation; change int to round in apply_transformation() of class RandomStructureTransformation.

Author: Jingyang Wang

pymatgen/transformations/standard_transformations.py

@@ -517,7 +517,7 @@ def apply_transformation(self, structure: Structure, n_copies: int) -> list[Stru
 
                 el_list = list(subl_comp_dict.keys())
                 el_concs = list(subl_comp_dict.values())
-                lengths = [int(el_conc * len(subl_indices)) for el_conc in el_concs]
+                lengths = [round(el_conc * len(subl_indices)) for el_conc in el_concs]
 
                 # randomly choose site indices for each element present in the sublattice
 

tests/transformations/test_standard_transformations.py

@@ -29,6 +29,7 @@
     OxidationStateDecorationTransformation,
     OxidationStateRemovalTransformation,
     PartialRemoveSpecieTransformation,
+    RandomStructureTransformation,
     PerturbStructureTransformation,
     PrimitiveCellTransformation,
     RemoveSpeciesTransformation,
@@ -320,6 +321,35 @@ def test_apply_transformations_best_first(self):
         assert len(trafo.apply_transformation(struct)) == 26
 
 
+class TestRandomStructureTransformation(unittest.TestCase):
+    def test_apply_transformation(self):
+        trafo = RandomStructureTransformation()
+        coords = []
+        coords.append([0, 0, 0])
+        coords.append([0.25, 0.25, 0.25])
+        lattice = Lattice(
+            [
+                [3.521253, 0.000000, 2.032996],
+                [1.173751, 3.319869, 2.032996],
+                [0.000000, 0.000000, 4.065993]
+            ]
+        )
+        
+        struct = Structure(
+            lattice,
+            [
+                {"Ga3+": 0.5, "In3+": 0.5},
+                {"As3-": 0.5, "P3-": 0.5}
+            ],
+            coords)
+        
+        struct.make_supercell([3, 3, 3])
+        
+        output = trafo.apply_transformation(struct, n_copies=5)
+        assert len(output) == 5
+        assert isinstance(output[0], Structure)
+
+
 class TestOrderDisorderedStructureTransformation(unittest.TestCase):
     def test_apply_transformation(self):
         trafo = OrderDisorderedStructureTransformation()