The Na 2 LiFeTeO 6 structure consists of several polyhedral inter-layers with sandwiching Na + ions, as shown in Figure reported by Nalbandyan et al. . The top and the bottom of the adjacent framework inter-layers are not identical, unlike the other materials, A 2 Ni 2 TeO 6 (A = Na, and K). The LiO 6 , FeO 6 , and TeO 6 octahedra are arranged in a honeycomb fashion inside the framework layer. The octahedral inter-layers are stabilized along the c-axis by Van der Waals forces and by interactions me- diated via the Na atoms occupying the inter-layers. To understand octahedral ordering, an octahedral density pattern of Na 2 LiFeTeO 6 along the y-direction from MD simulation is shown in Figure , in which the FeO 6 octahedra are located on the top and the bottom along the c-axis. The Na + ion density pattern in the conduction plane is significantly influenced by the local octahedral sequences, most importantly where the inter-layer distance is small (∼ 3.5 Å). The octahedral density pattern from MD simulation follows same ordering as reported in X-ray structure. The inter-layer octahedral density are found to be a slightly off particularly at high temperatures because of thermal oscillation that leads to polyhedral layer-sliding. Furthermore, the average cell parameters of Na Herein, we want to emphasize that most of the cases the Li-atoms are consider to be mobile; in this case they form immobile framework. In contrast, the loose coordination to the framework polyhedral inter-layer allocates several cationic sub-lattices in the conduction layer for facile cationic conduction, as identified in the reported experimental structure. The facile Na + ion diffusion is reflected in the plot of the mean square displacements (MSD) against time (figure ). The closely packed framework octahedral layers parallel to the ab-plane restrict the Na + ion diffusion along the c-axis direction of the cell, as reflected in the inset of Figure (b) (less than 0.04 Å2 ). Therefore, cationic mobility appears to be restricted within the sublattices oriented parallel to the ab-plane, affirming the diffusion to be highly anisotropic (or layer diffusion), as also observed in the previous studies .