new flag for AutoOxi (#4150)

new flag for AutoOxi

src/pymatgen/transformations/standard_transformations.py

@@ -107,6 +107,7 @@ def __init__(
         max_radius=4,
         max_permutations=100000,
         distance_scale_factor=1.015,
+        zeros_on_fail=False,
     ):
         """
         Args:
@@ -121,12 +122,16 @@ def __init__(
                 calculation-relaxed structures, which may tend to under (GGA) or
                 over bind (LDA). The default of 1.015 works for GGA. For
                 experimental structure, set this to 1.
+            zeros_on_fail (bool): If True and the BVAnalyzer fails to come up
+                with a guess for the oxidation states, we will set the all the
+                oxidation states to zero.
         """
         self.symm_tol = symm_tol
         self.max_radius = max_radius
         self.max_permutations = max_permutations
         self.distance_scale_factor = distance_scale_factor
         self.analyzer = BVAnalyzer(symm_tol, max_radius, max_permutations, distance_scale_factor)
+        self.zeros_on_fail = zeros_on_fail
 
     def apply_transformation(self, structure):
         """Apply the transformation.
@@ -137,7 +142,14 @@ def apply_transformation(self, structure):
         Returns:
             Oxidation state decorated Structure.
         """
-        return self.analyzer.get_oxi_state_decorated_structure(structure)
+        try:
+            return self.analyzer.get_oxi_state_decorated_structure(structure)
+        except ValueError as er:
+            if self.zeros_on_fail:
+                struct_ = structure.copy()
+                struct_.add_oxidation_state_by_site([0] * len(struct_))
+                return struct_
+            raise ValueError(f"BVAnalyzer failed with error: {er}")
 
 
 class OxidationStateRemovalTransformation(AbstractTransformation):

tests/transformations/test_standard_transformations.py

@@ -200,6 +200,15 @@ def test_as_from_dict(self):
         trafo = AutoOxiStateDecorationTransformation.from_dict(dct)
         assert trafo.analyzer.dist_scale_factor == 1.015
 
+    def test_failure(self):
+        trafo_fail = AutoOxiStateDecorationTransformation()
+        trafo_no_fail = AutoOxiStateDecorationTransformation(zeros_on_fail=True)
+        struct_metal = Structure.from_spacegroup("Fm-3m", Lattice.cubic(3.677), ["Cu"], [[0, 0, 0]])
+        with pytest.raises(ValueError, match="BVAnalyzer failed with error"):
+            trafo_fail.apply_transformation(struct_metal)
+        zero_oxi_struct = trafo_no_fail.apply_transformation(struct_metal)
+        assert all(site.specie.oxi_state == 0 for site in zero_oxi_struct)
+
 
 class TestOxidationStateRemovalTransformation:
     def test_apply_transformation(self):