Get the CompoundPhaseDiagram object, which can then be used for
        plotting.

        Returns:
            (CompoundPhaseDiagram)

def get_compound_pd(self):
        """
        Get the CompoundPhaseDiagram object, which can then be used for
        plotting.

        Returns:
            (CompoundPhaseDiagram)
        """
        # For this plot, since the reactions are reported in formation
        # energies, we need to set the energies of the terminal compositions
        # to 0. So we make create copies with 0 energy.
        entry1 = PDEntry(self.entry1.composition, 0)
        entry2 = PDEntry(self.entry2.composition, 0)

        cpd = CompoundPhaseDiagram(
            self.rxn_entries + [entry1, entry2],
            [Composition(entry1.composition.reduced_formula),
             Composition(entry2.composition.reduced_formula)],
            normalize_terminal_compositions=False) 
        return cpd