Figure 2.

(a) Rietveld refinement against the PXRD pattern using the four phases of a multiphase Ni–Se–O–Cl sample determined from RED data (λ = 1.5418 Å). Unindexed peaks are marked by asterisks (*). TEM images showing crystals of (b) Phase 1, (c) Phase 2, (d) Phase 3 and (e) Phase 4 used for RED data collection. The corresponding three-dimensional reciprocal lattices of (f) Phase 1, (g) Phase 2, (h) Phase 3 and (i) Phase 4 reconstructed from RED data. Structure models of (j) Phase 1 (NiSeO₃), (k) Phase 2 (Ni₃Se₄O₁₀Cl₂), (l) Phase 3 (Ni₅Se₆O₁₆Cl₄H₂) and (m) Phase 4 (Ni₅Se₄O₁₂Cl₂) determined from RED data. The NiO₄Cl₂, NiO₅Cl and NiO₆ octahedra are in grey, SeO₃ trigonal pyramids and Se atoms in yellow green, O atoms in red, Cl atoms in green and H atoms in brown. More information is given by Yun et al. (2014 ▶), from where this image is reproduced.