code: def get_percentage_lattice_parameter_changes(self):
          
          initial_latt = self.initial.lattice
          final_latt = self.final.lattice
          d = {l: getattr(final_latt, l) / getattr(initial_latt, l) - 1
               for l in ["a", "b", "c"]}
          return d
docs: Returns the percentage lattice parameter changes.
  
          Returns:
              A dict of the percentage change in lattice parameter, e.g.,
              {'a': 0.012, 'b': 0.021, 'c': -0.031} implies a change of 1.2%,
              2.1% and -3.1% in the a, b and c lattice parameters respectively.