. 2021 Feb 22;77(Pt 3):144–151. doi: 10.1107/S2053229621001650

Table 9. Absolute atomic displacements (Å), arithmetic mean (d _av, Å), degree of lattice distortion (S) and measure of similarity (Δ) in the isotypic NaM(CrO₄)(H₂O)₂ (M = Al and Fe) structures relative to NaSc(CrO₄)₂(H₂O)₂ ^a .

	M = Al^b	M = Fe^c
Na1	0.0595	0.0773
M1	0	0
Cr1	0.0839	0.0536
O1	0.1477	0.1608
O2	0.1227	0.1436
O3	0.0595	0.0395
O4	0.0395	0.0520
O5	0.1916	0.0751

d _av	0.0964	0.0805
Δ	0.023	0.019
S	0.0186	0.0107

Notes: (a) H atoms were omitted from comparison because in the M = Al and Fe structures, H atoms were not localized. (b) Unit-cell parameters a = 14.080 (10), b = 5.338 (3), c = 10.655 (6) Å and β = 110.33 (5)° (Cudennec & Riou, 1977 ▸). (c) Unit-cell parameters a = 14.247 (2), b = 5.425 (5), c = 10.689 (2) Å and β = 109.30 (1)° (Hardy & Gravereau, 1970 ▸).

Table 9. Absolute atomic displacements (Å), arithmetic mean (d av, Å), degree of lattice distortion (S) and measure of similarity (Δ) in the isotypic NaM(CrO4)(H2O)2 (M = Al and Fe) structures relative to NaSc(CrO4)2(H2O)2 a .

Table 9. Absolute atomic displacements (Å), arithmetic mean (d _av, Å), degree of lattice distortion (S) and measure of similarity (Δ) in the isotypic NaM(CrO₄)(H₂O)₂ (M = Al and Fe) structures relative to NaSc(CrO₄)₂(H₂O)₂ ^a .