Figure 2.
Structural model for the P′3 phase as determined from combined refinement of SXRD and NPD data. The structural model with anisotropic ADPs for the O(3) site is shown along the (a) c and (b) b directions. The structural model with anisotropic ADPs for the Na(1) site, and split O(3)-site is shown along the (c) c and (b) b directions. (e) Na/vacancy zigzag ordering of edge-sharing occupied Na trigonal prismatic sites (in yellow) in the Na-layer (pink zigzags overlaid for visual clarity to show the repeating zigzag motif). (f) Honeycomb ordering of the two Ni sites on the triangular Ni lattice. In (e)/(f) 1 × 3 × 3 unit cells are shown, while the unit cell itself is denoted by the “black box outline”.