Figure 1

Schematic drawing of the orthorhombic perovskite structure projected onto the $a\mathrm{\text{−}}b$ plane. The cubic perovskite unit cell is shown with dashed lines. O(2) is located at the corner of octahedra shown as a square in this plot. O(1) is at the apical position off the plane.Reuse & Permissions

Figure 2

Lattice parameters versus ionic radius of the $R^{3+}$ ion. Circles, triangles, and squares stand for $b$, $c/\sqrt{2}$, and $a$, respectively. The rare-earth radius in nine coordination is chosen since it is the highest coordination number available for all tabulated rare earths. Lines in the figure are a guide to the eyes. Points in red are calculated by SPuDS. All data shown in black are from Ref. 4. The data from single-crystal diffraction are shown in blue. Data except for those in black are from Ref. 17 for $R{\mathrm{T}\mathrm{i}\mathrm{O}}_3$, Refs. 18, 19, 20, 21, 22 for $R{\mathrm{V}\mathrm{O}}_3$, Refs. 23, 24 for $R{\mathrm{M}\mathrm{n}\mathrm{O}}_3$, Refs. 25, 26 for $R{\mathrm{F}\mathrm{e}\mathrm{O}}_3$, Ref. 8, 27 for $R{\mathrm{C}\mathrm{o}\mathrm{O}}_3$, and Refs. 28, 29, 30, 31 for $R{\mathrm{N}\mathrm{i}\mathrm{O}}_3$.Reuse & Permissions

Figure 3

Tilting angle $\omega$ and $\mathrm{O}\mathrm{\text{−}}M\mathrm{\text{−}}\mathrm{O}$ angle $\alpha$ of octahedra versus IR for $R{\mathrm{F}\mathrm{e}\mathrm{O}}_3$.Reuse & Permissions