In the previous sections, we showed how samples with x = 0.5 and 0.625, based on the Na2ZnCl4 structure, exhibit significantly enhanced conductivity with respect to the end member NZC. We also showed how this does not correlate with the amorphous phase present in the samples; rather we observed a novel signal in the ss-NMR of these intermediate samples (Figure ), whose origin and correlation with conductivity is yet to be clarified. The origin of the significantly enhanced ionic conductivity is explored by theoretical MD and NEB simulations on machine-learned potential MACE-MP-0/D3(BJ)-level and with theoretical NMR calculations on PBE/D3(BJ)-level and experimental ss-NMR measurements. Herein, in the NZC structure, Na atoms in the Na1 sublattice surrounded by Al 3+ tetrahedra are denoted as Na1(Al), while Na atoms in the Na1 sublattice surrounded by both Al 3+ Cl4 tetrahedra and Zn 2+ Cl4 tetrahedra are denoted as Na1(Zn/Al); the same nomenclature also applies to Na atoms in the Na2 sublattice.