Figure 2 Comparison of the Nd2Ti2O7 structures, (a) present study, (b) Scheunemann & Müller-Buschbaum (1975), (c) Harvey et al. (2005). Unit cells and atomic parameters are shifted for comparison. Two kinds of perovskite-type slabs are illustrated using green- and orange-coloured TiO6 octahedra, respectively. The small black arrows indicate the displacements of Nd atoms (red spheres) along b* with respect to the dashed lines drawn parallel to a.  [article HTML]