code: def _get_elements(self, site):
          
          try:
              if isinstance(site.specie, Element):
                  return [site.specie]
              return [Element(site.specie)]
          except:
              return site.species.elements
docs: Get the list of elements for a Site
  
          Args:
               site (Site): Site to assess
          Returns:
              [Element]: List of elements