Merge cc690eb into dcbbe00

materialsproject · Jan 23, 2023 · fe0f6e0 · fe0f6e0
2 parents dcbbe00 + cc690eb
commit fe0f6e0
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diff --git a/pymatgen/analysis/phase_diagram.py b/pymatgen/analysis/phase_diagram.py
@@ -416,6 +416,8 @@ def _compute(self) -> dict[str, Any]:
         dim = len(elements)
 
         entries = sorted(self.entries, key=lambda e: e.composition.reduced_composition)
+        if len(entries) == 0:
+            raise ValueError("Unable to build phase diagram without entries.")
 
         el_refs: dict[Element, PDEntry] = {}
         min_entries: list[PDEntry] = []

diff --git a/pymatgen/analysis/tests/test_phase_diagram.py b/pymatgen/analysis/tests/test_phase_diagram.py
@@ -630,6 +630,12 @@ def test_el_refs(self):
         # Check the keys in el_refs dict have been updated to Element object via PhaseDiagram class.
         assert all(isinstance(el, Element) for el in pd.el_refs)
 
+    def test_entries_length_error(self):
+        # Assert PhaseDiagram class raises ValueError when building phase diagram with no entries
+        entriesList = []
+        with pytest.raises(ValueError, match="Unable to build phase diagram without entries."):
+            PhaseDiagram(entriesList)
+
 
 class GrandPotentialPhaseDiagramTest(unittest.TestCase):
     def setUp(self):