code: def are_equal(self, sp1, sp2):
          
          comp1 = Composition(sp1)
          comp2 = Composition(sp2)
          return comp1.get_el_amt_dict() == comp2.get_el_amt_dict()
docs: True if element:amounts are exactly the same, i.e.,
          oxidation state is not considered.
  
          Args:
              sp1: First species. A dict of {specie/element: amt} as per the
                  definition in Site and PeriodicSite.
              sp2: Second species. A dict of {specie/element: amt} as per the
                  definition in Site and PeriodicSite.
  
          Returns:
              Boolean indicating whether species are the same based on element
              and amounts.