added ll and ur as suggested by @pshriwise

openmc/bounding_box.py

@@ -13,10 +13,14 @@ class BoundingBox(tuple):
 
     Attributes
     ----------
-    volume: float
-        The volume of the bounding box in cm3
     center: numpy.array
         x, y, z coordinates of the center of the bounding box in cm.
+    lower_left: numpy.array
+        The x, y, z coordinates of the lower left corner of the bounding box
+    upper_right
+        The x, y, z coordinates of the upper right corner of the bounding box
+    volume: float
+        The volume of the bounding box in cm3
     """
 
     def __init__(self, corners):
@@ -34,6 +38,16 @@ class BoundingBox(tuple):
         """The center x, y, z coordinates of the bounding box"""
         return (self.corners[0] + self.corners[1]) / 2
 
+    @property
+    def lower_left(self):
+        """The x, y, z coordinates of the lower left corner of the bounding box"""
+        return self.corners[0]
+
+    @property
+    def upper_right(self):
+        """The x, y, z coordinates of the upper right corner of the bounding box"""
+        return self.corners[1]
+
     @property
     def volume(self):
         """The volume of the bounding box"""

tests/unit_tests/test_bounding_box.py

@@ -26,6 +26,30 @@ def test_bounding_box_volume(bb, expected):
     assert bb.volume == expected
 
 
+@pytest.mark.parametrize(
+    "bb, expected",
+    [
+        (test_bb_1, np.array([-10.0, -20.0, -30.0])),
+        (test_bb_2, np.array([1.0, 2.0, 3.0])),
+        (test_bb_3, np.array([-10.0, -20.0, -30.0])),
+    ],
+)
+def test_bounding_lower_left(bb, expected):
+    assert np.array_equiv(expected, bb.lower_left)
+
+
+@pytest.mark.parametrize(
+    "bb, expected",
+    [
+        (test_bb_1, np.array([1.0, 2.0, 3.0])),
+        (test_bb_2, np.array([11.0, 22.0, 33.0])),
+        (test_bb_3, np.array([-1.0, -2.0, -3.0])),
+    ],
+)
+def test_bounding_upper_right(bb, expected):
+    assert np.array_equiv(expected, bb.upper_right)
+
+
 @pytest.mark.parametrize(
     "bb, expected",
     [