diff --git a/ramannoodle/structure/reference.py b/ramannoodle/structure/reference.py
index f56e3b7..290b85b 100644
--- a/ramannoodle/structure/reference.py
+++ b/ramannoodle/structure/reference.py
@@ -156,7 +156,8 @@ def positions(self) -> NDArray[np.float64]:
         """
         return self._positions.copy()
 
-    def get_num_nonequivalent_atoms(self) -> int:
+    @property
+    def num_nonequivalent_atoms(self) -> int:
         """Get number of nonequivalent atoms."""
         assert self._symmetry_dict is not None
         return len(set(self._symmetry_dict["equivalent_atoms"]))
diff --git a/test/tests/test_structure.py b/test/tests/test_structure.py
index 78eb8f6..e27e745 100644
--- a/test/tests/test_structure.py
+++ b/test/tests/test_structure.py
@@ -147,7 +147,7 @@ def test_ref_structure(
     """Test StructuralSymmetry (normal)."""
     # Equivalent atoms test
     ref_structure = outcar_ref_structure_fixture
-    assert ref_structure.get_num_nonequivalent_atoms() == known_nonequivalent_atoms
+    assert ref_structure.num_nonequivalent_atoms == known_nonequivalent_atoms
 
     # Equivalent displacement test
     displacement = ref_structure.positions * 0  # pylint: disable=protected-access