Figure 4
From: Emergence of Multiple Superconducting Phases in (NH3)yMxFeSe (M: Na and Li)
Crystal structures determined for (a) (NH3)yLixFeSe (ref. 2) and (d) (NH3)yCsxFeSe (ref. 5) and the structure suggested for (b) high-Tc phase and (c) low-Tc phase of (NH3)yNaxFeSe. Green, brown, blue, yellow and dark green balls refer to Se, Fe, Li, Na and Cs, respectively. Ball sizes reflect relative ionic radii. N and H are not shown. All schematic structures are drawn by ourselves based on the crystal structures determined for (NH3)yLixFeSe (ref. 2) and (NH3)yCsxFeSe (ref. 5) and those of high-Tc and low-Tc phases of (NH3)yNaxFeSe are drawn by ourselves using atomic coordinates of (NH3)yLixFeSe (ref. 2) and (NH3)yCsxFeSe (ref. 5), respectively and their lattice constants determined in this study.
