Herein, our focus is on the atomistic origin of high ionic conductivity in Na 2 LiFeTeO 6 . We calculated the threedimensional isosurface population density along with the polyhedral framework, as shown in Figures ) and (b) for understanding of Na + ion transport path. The Na + ion density lies inside the octahedral framework layer, which is also reflected in the MSD plot of the Na + ions along the z-direction. For further clarity of the Na + ions' diffusion paths, the two-dimensional population density (the number of ions per unit area) pattern and the average potential energy of the Na + ions in the conduc- The average potential energy of the individual cations is calculated using Eq. 6 (detailed in the METHODOL-OGY section IV) and projected onto a 2D grid in the ab-plane. Both the projected population density and the average potential energy are also replicated in 2×2 unit cells in the conduction plane for continuity, as shown in Figures ) and (d). The high density areas and their local environment-the octahedral centers and the Na sites-are indicated on top of the density and energy patterns. There are five high-density maxima in the population density profile, whereas there are four available Na + ions per unit cell per inter-layer. Therefore, the Na + ions can occupy the high-density maxima and can diffuse as well through the available vacant sites; as a result, the occupancy at each high-density area has to be less than unity. The occupancy at each maximaum density site was calculated using Bader charge analysis code, which was principlly developed for electron density analysis . Herein, the iso-surface density of Na + ion was used instead of charge density. The occupancy at S1 and S2 are close to unity, whereas close to half occupancy is identified at S3. For cationic channel connectivity, two types of ring connectivity are observed, as marked by circles: ring 1 (sky blue circle) consists of three high-density maxima, whereas ring 2 (orange circle) is formed by two maxima. The sites are marked S1, S2, and S3, as shown in Figure (c). Among the three high-density sites, S1 and S3 find good agreement with the reported crystallographic sites, whereas site S2 deviates from any reported crystallographic site. Furthermore, the sites S2 and S3 are located inside the circles formed by the framework octahedral centers, whereas site S1 is identified on the side of a triangle. None of the Na sites are found on top of the octahedral center because of strong repulsion between the top and bottom octahedra and the Na + ions.