code: def relative_probability( self, l1, l2, c1, c2 ):
          
          if self.site_energies:
              site_delta_E = self.site_energies[ l2 ] - self.site_energies[ l1 ]
          else:
              site_delta_E = 0.0
          if self.nn_energy:
              delta_nn = c2 - c1 - 1 # -1 because the hopping ion is not counted in the final site occupation number
              site_delta_E += delta_nn * self.nn_energy
          return metropolis( site_delta_E )
docs: The relative probability for a jump between two sites with specific site types and coordination numbers.
  
          Args:
              l1 (Str): Site label for the initial site.
              l2 (Str): Site label for the final site.
              c1 (Int): Coordination number for the initial site.
              c2 (Int): Coordination number for the final site.
     
          Returns:
              (Float): The relative probability of this jump occurring.