Bump pypa/cibuildwheel from 2.14.1 to 2.16.2

.github/workflows/test.yml

@@ -180,7 +180,7 @@ jobs:
     steps:
       - uses: actions/checkout@v3
       - name: Build wheels
-        uses: pypa/cibuildwheel@v2.14.1
+        uses: pypa/cibuildwheel@v2.16.2
         env:
           CIBW_BUILD: cp${{ matrix.python-version }}-*
       - name: Save artifact

pymatgen/core/structure.py

@@ -2988,6 +2988,14 @@ def __init__(
         else:
             self._spin_multiplicity = 1 if nelectrons % 2 == 0 else 2
 
+        # Remind user about the unusual spin multiplicity of ground state O2
+        if self.species == [Element("O"), Element("O")] and self.charge == 0 and self._spin_multiplicity != 3:
+            warnings.warn(
+                f"You have specified a spin multiplicity of {self._spin_multiplicity} for "
+                "an O2 molecule; however the ground state of molecular O2 has a spin multiplicity of 3. "
+                "If this was intentional, you can safely ignore this message."
+            )
+
     @property
     def charge(self) -> float:
         """Charge of molecule."""