
Schematic representation of the five irrep distortions allowed in the Pbnm configuration, corresponding to \mathrm{M}_{2}^{+}, \mathrm{M}_{3}^{+}, \mathrm{R}_{4}^{+}, \mathrm{R}_{5}^{+}and \mathrm{X}_{5}^{+}. Fe/Ru disordered octahedra in purple, the A / A^{\prime}-site Sr/Ln cations in green and, oxygen atoms, in red. As a reference, we are also plotting the simple perovskite cubic cell (red) and the double perovskite orthorhombic cell (black). The polarization vectors are shown by small black arrows.
auto-cropped from the OCR Markdown crop box (stage B); materials and kind to be reviewed in Phase 1