diff --git a/lib/matplotlib/_mathtext.py b/lib/matplotlib/_mathtext.py
index 551898d546ac..eb6e6047f9bf 100644
--- a/lib/matplotlib/_mathtext.py
+++ b/lib/matplotlib/_mathtext.py
@@ -1830,6 +1830,7 @@ def set_names_and_parse_actions():
             | p.underset
             | p.sqrt
             | p.overline
+            | p.auto_delim
         )
 
         p.simple        <<= (
@@ -2206,6 +2207,16 @@ def subsuper(self, s, loc, toks):
             result = Hlist([vlist])
             return [result]
 
+        # Set the minimum shifts for the superscript and subscript (node756).
+        constants = _get_font_constant_set(state)
+        if isinstance(nucleus, Char):
+            shift_up = 0
+            shift_down = 0
+        else:
+            drop_amount = constants.subdrop * xHeight * SHRINK_FACTOR
+            shift_up = nucleus.height - drop_amount
+            shift_down = nucleus.depth + drop_amount
+
         # We remove kerning on the last character for consistency (otherwise
         # it will compute kerning based on non-shrunk characters and may put
         # them too close together when superscripted)
@@ -2232,7 +2243,6 @@ def subsuper(self, s, loc, toks):
             nucleus = Hlist([nucleus])
 
         # Handle regular sub/superscripts
-        constants = _get_font_constant_set(state)
         lc_height   = last_char.height
         lc_baseline = 0
         if self.is_dropsub(last_char):
@@ -2254,35 +2264,44 @@ def subsuper(self, s, loc, toks):
                 subkern = 0
 
         if super is None:
-            # node757
+            # Align subscript without superscript (node757).
             x = Hlist([Kern(subkern), sub])
             x.shrink()
             if self.is_dropsub(last_char):
                 shift_down = lc_baseline + constants.subdrop * xHeight
             else:
-                shift_down = constants.sub1 * xHeight
+                shift_down = max(shift_down, constants.sub1 * xHeight,
+                                 x.height - xHeight * 4 / 5)
             x.shift_amount = shift_down
         else:
+            # Align superscript (node758).
             x = Hlist([Kern(superkern), super])
             x.shrink()
             if self.is_dropsub(last_char):
                 shift_up = lc_height - constants.subdrop * xHeight
             else:
-                shift_up = constants.sup1 * xHeight
+                shift_up = max(shift_up, constants.sup1 * xHeight,
+                               x.depth + xHeight / 4)
             if sub is None:
                 x.shift_amount = -shift_up
-            else:  # Both sub and superscript
+            else:
+                # Align subscript with superscript (node759).
                 y = Hlist([Kern(subkern), sub])
                 y.shrink()
                 if self.is_dropsub(last_char):
                     shift_down = lc_baseline + constants.subdrop * xHeight
                 else:
-                    shift_down = constants.sub2 * xHeight
-                # If sub and superscript collide, move super up
-                clr = (2.0 * rule_thickness -
+                    shift_down = max(shift_down, constants.sub2 * xHeight)
+                # If the subscript and superscript are too close to each other,
+                # move the subscript down.
+                clr = (4 * rule_thickness -
                        ((shift_up - x.depth) - (y.height - shift_down)))
                 if clr > 0.:
-                    shift_up += clr
+                    shift_down += clr
+                    clr = xHeight * 4 / 5 - shift_up + x.depth
+                    if clr > 0:
+                        shift_up += clr
+                        shift_down -= clr
                 x = Vlist([
                     x,
                     Kern((shift_up - x.depth) - (y.height - shift_down)),