Strip HTML tags from electronic_structure. Fixes #1847.

pymatgen/core/periodic_table.py

@@ -323,9 +323,9 @@ def __init__(self, symbol: str):
 
         .. attribute:: electronic_structure
 
-            Electronic structure. Simplified form with HTML formatting.
+            Electronic structure.
             E.g., The electronic structure for Fe is represented as
-            [Ar].3d<sup>6</sup>.4s<sup>2</sup>
+            [Ar].3d6.4s2
 
         .. attribute:: atomic_orbitals
 
@@ -459,8 +459,7 @@ def __getattr__(self, item):
         if item in ["mendeleev_no", "electrical_resistivity",
                     "velocity_of_sound", "reflectivity",
                     "refractive_index", "poissons_ratio", "molar_volume",
-                    "electronic_structure", "thermal_conductivity",
-                    "boiling_point", "melting_point",
+                    "thermal_conductivity", "boiling_point", "melting_point",
                     "critical_temperature", "superconduction_temperature",
                     "liquid_range", "bulk_modulus", "youngs_modulus",
                     "brinell_hardness", "rigidity_modulus",
@@ -517,6 +516,10 @@ def data(self):
         """
         return self._data.copy()
 
+    @property
+    def electronic_structure(self):
+        return re.sub("</*sup>", "", self._data["Electronic structure"])
+
     @property
     def average_ionic_radius(self):
         """
@@ -618,10 +621,10 @@ def full_electronic_structure(self):
         [(1, "s", 2), (2, "s", 2), (2, "p", 6), (3, "s", 2), (3, "p", 6),
         (3, "d", 6), (4, "s", 2)]
         """
-        estr = self._data["Electronic structure"]
+        estr = self.electronic_structure
 
         def parse_orbital(orbstr):
-            m = re.match(r"(\d+)([spdfg]+)<sup>(\d+)</sup>", orbstr)
+            m = re.match(r"(\d+)([spdfg]+)(\d+)", orbstr)
             if m:
                 return int(m.group(1)), m.group(2), int(m.group(3))
             return orbstr

pymatgen/core/tests/test_periodic_table.py

@@ -63,6 +63,8 @@ def test_full_electronic_structure(self):
         for k, v in testsets.items():
             self.assertEqual(Element(k).full_electronic_structure, v)
 
+        self.assertEqual(Element.Ac.electronic_structure, '[Rn].6d1.7s2')
+
     def test_valence(self):
         testsets = {"O": (1, 4),
                     "Fe": (2, 6),