diff --git a/nvalchemi/data/batch.py b/nvalchemi/data/batch.py
index c26629e..604dac9 100644
--- a/nvalchemi/data/batch.py
+++ b/nvalchemi/data/batch.py
@@ -583,6 +583,11 @@ def get_data(self, idx: int) -> AtomicData:
         """
         if idx < 0:
             idx = self.num_graphs + idx
+        if not (0 <= idx < self.num_graphs):
+            raise IndexError(
+                f"graph index {idx} is out of range for batch with "
+                f"{self.num_graphs} graph(s)"
+            )
 
         data: dict[str, Any] = {}
 
diff --git a/test/data/test_batch.py b/test/data/test_batch.py
index f1db7cd..a0d9a38 100644
--- a/test/data/test_batch.py
+++ b/test/data/test_batch.py
@@ -281,6 +281,14 @@ def test_get_data_negative_index(self):
         last = batch.get_data(-1)
         assert last.num_nodes == 3
 
+    @pytest.mark.parametrize("idx", [-3, -4, -5, -100, 2, 3, 100])
+    def test_get_data_out_of_range_raises(self, idx):
+        d1 = _minimal_atomic_data(2)
+        d2 = _minimal_atomic_data(3)
+        batch = Batch.from_data_list([d1, d2])
+        with pytest.raises(IndexError):
+            batch.get_data(idx)
+
     def test_to_data_list(self):
         d1 = _minimal_atomic_data(2)
         d2 = _minimal_atomic_data(3)