Table 2. Structural data for both polytypes.

	MDO-1 polytype	MDO-2 polytype
Crystal data
Chemical formula	Al9.12Ca5.98Fe30.7O72Mg5.34Si0.86
M r	3506.1
Crystal system	Triclinic	Monoclinic
Space group		P21/n
a, b, c (Å)	10.3279 (2), 10.4340 (2), 14.3794 (2)	10.3277 (2), 27.0134 (4), 10.4344 (2)
α, β, γ (°)	93.4888 (12), 107.3209 (14), 109.6626 (14)	90, 109.668 (2), 90
V (Å3)	1370.49 (5)	2741.22 (9)
Z	1	2
Refinement
Δρmax,Δρmin (e Å−3)	1.11, −1.53	1.09, −0.81
Volume fraction (%)	37.5 (7)	62.5 (7)