code: def get_oxidation_state_decorated_structure(self):
          
          structure = self.chgcar.structure
          charges = [-self.get_charge_transfer(i)
                     for i in range(len(structure))]
          structure.add_oxidation_state_by_site(charges)
          return structure
docs: Returns an oxidation state decorated structure.
  
          Returns:
              Returns an oxidation state decorated structure. Requires POTCAR
              to be supplied.