Superspace description of the modulated structure of the metal-salt-hybrid Bi7 − δNi2Br5 − 2δ (δ = 1/9)

Wahl, B.; Ruck, M.

doi:10.1107/S0108768109029760

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Superspace description of the modulated structure of the metal-salt-hybrid Bi_7 − δNi₂Br_{5 − 2δ} (δ = 1/9)

B. Wahl and M. Ruck

The compound Bi_7 − δNi₂Br_{5 − 2δ} = (Bi₃Ni)₂[Bi_1 − δBr₄]Br_1 −2δ (δ = 1/9) is a sub-bromide of the intermetallic phase Bi₃Ni. Its crystal structure contains metallic rods, $^1_{\infty}$ [Bi₃Ni], which are embedded in a salt-like matrix of bromido-bismuthate(III) and bromide anions. The non-stoichiometry originates from the variation of the number n of trans edge-sharing octahedra in the [Bi_nBr_4n + 2]^{(n + 2)−} oligomers (3 ≤ n ≤ 5), as well as from vacancies on the sites of the isolated Br atoms. The simplified structure is described in the orthorhombic space group Cmcm with a = 4.0660 (4), b = 23.305 (3), c = 17.130 (2) Å. It shows a statistical distribution of vacancies and orientational disorder of the concatenated octahedra. By choosing the modulation vector q = a*/9 + b*/2, the additional weak reflections of the diffraction pattern can be indexed. In the [3 + 1]-dimensional superspace group Pmnm(α½0)000, an ordered structure model is achieved. The modulated crystal structure bears a strong resemblance to the somewhat higher oxidized sub-bromide Bi_7 − δNi₂Br₅ (δ = 1/9).

Keywords: modulated structure; orientational disorder; one-dimensional matrix.

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Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S0108768109029760/sn5087sup1.cif Contains datablocks global, Bi7Ni2Br5average, Bi7Ni2Br5mod, Bi7Ni2Br5simplified
	Structure factor file (CIF format) https://doi.org/10.1107/S0108768109029760/sn5087Bi7Ni2Br5averagesup2.hkl Contains datablock Bi7Ni2Br5average
	Structure factor file (CIF format) https://doi.org/10.1107/S0108768109029760/sn5087Bi7Ni2Br5modsup3.hkl Contains datablock Bi7Ni2Br5mod
	Structure factor file (CIF format) https://doi.org/10.1107/S0108768109029760/sn5087Bi7Ni2Br5simplifiedsup4.hkl Contains datablock Bi7Ni2Br5simplified

Computing details top

For all compounds, program(s) used to refine structure: (Jana2000; Petricek and Dusek, 2000); software used to prepare material for publication: (Jana2000; Petricek and Dusek, 2000).

Figures top

(Bi7Ni2Br5average) top

Crystal data top

Bi_6.889Br_4.778Ni₂	F(000) = 3183
M_r = 1938.8	D_x = 7.941 Mg m⁻³
Orthorhombic, Pmnm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P -2yca;-2zc	Cell parameters from 14269 reflections
a = 4.0660 (4) Å	θ = 1.8–24.5°
b = 23.305 (3) Å	µ = 88.43 mm⁻¹
c = 17.130 (2) Å	T = 293 K
V = 1623.2 (3) Å³	Needle, black
Z = 4	0.6 × 0.08 × 0.02 mm

Data collection top

Imaging plate diffractometer STOE IPDS II	1631 independent reflections
Radiation source: fine-focus sealed tube	1075 reflections with I > 3σ(I)
Graphite monochromator	R_int = 0.114
incremental rotation scans	θ_max = 24.6°, θ_min = 1.5°
Absorption correction: numerical microscopic crystal description optimized with X-SHAPE 1.06 (Stoe, 1999)	h = −4→4
T_min = 0.02, T_max = 0.204	k = −27→27
17051 measured reflections	l = −20→20

Refinement top

Refinement on F²	105 parameters
R[F² > 2σ(F²)] = 0.060	Weighting scheme based on measured s.u.'s w = 1/(σ²(I) + 0.000025I²)
wR(F²) = 0.085	(Δ/σ)_max = 0.0002
S = 6.06	Δρ_max = 2.17 e Å⁻³
1631 reflections	Δρ_min = −2.30 e Å⁻³

Crystal data top

Bi_6.889Br_4.778Ni₂	V = 1623.2 (3) Å³
M_r = 1938.8	Z = 4
Orthorhombic, Pmnm	Mo Kα radiation
a = 4.0660 (4) Å	µ = 88.43 mm⁻¹
b = 23.305 (3) Å	T = 293 K
c = 17.130 (2) Å	0.6 × 0.08 × 0.02 mm

Data collection top

Imaging plate diffractometer STOE IPDS II	1631 independent reflections
Absorption correction: numerical microscopic crystal description optimized with X-SHAPE 1.06 (Stoe, 1999)	1075 reflections with I > 3σ(I)
T_min = 0.02, T_max = 0.204	R_int = 0.114
17051 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.060	105 parameters
wR(F²) = 0.085	Δρ_max = 2.17 e Å⁻³
S = 6.06	Δρ_min = −2.30 e Å⁻³
1631 reflections

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Bi11	0.75	0.07204 (13)	0.58899 (11)	0.0222 (9)	0.5
Bi21	0.75	0.05552 (13)	0.39189 (10)	0.0218 (8)	0.5
Bi31	0.25	0.14575 (15)	0.47422 (14)	0.0349 (10)	0.5
Ni11	0.25	0.0320 (4)	0.4977 (3)	0.021 (3)	0.5
Bi12	0.75	0.42826 (13)	0.41255 (11)	0.0260 (9)	0.5
Bi22	0.75	0.44695 (15)	0.61086 (12)	0.0324 (10)	0.5
Bi32	0.25	0.35592 (16)	0.52982 (16)	0.0486 (13)	0.5
Ni12	0.25	0.4688 (4)	0.5050 (4)	0.022 (3)	0.5
Br11	0.25	0.0023 (6)	0.25	0.0468 (16)	0.5
Bi41a	0.75	0.2635 (4)	0.25	0.044 (4)	0.273 (11)
Bi41b	0.25	0.2677 (6)	0.25	0.044 (5)	0.169 (9)
Br21a	0.25	0.1759 (11)	0.25	0.042 (2)	0.282 (12)
Br21b	0.25	0.1529 (15)	0.25	0.042 (2)	0.218 (12)
Br31a	0.25	0.3538 (10)	0.25	0.039 (2)	0.282 (12)
Br31b	0.25	0.3995 (10)	0.25	0.039 (2)	0.1652
Br41a	0.75	0.2662 (9)	0.4205 (7)	0.0414 (13)	0.218 (10)
Br41b	0.75	0.2638 (6)	0.3789 (7)	0.0414 (13)	0.267
Br12	0.75	0.5024 (10)	0.25	0.0468 (16)	0.312 (12)
Bi42a	0.25	0.7614 (4)	0.25	0.042 (5)	0.219 (11)
Bi42b	0.75	0.7574 (4)	0.25	0.043 (3)	0.225 (9)
Br22a	0.75	0.6691 (8)	0.25	0.042 (2)	0.312 (11)
Br22b	0.75	0.6297 (11)	0.25	0.042 (2)	0.19 (2)
Br32a	0.75	0.8506 (12)	0.25	0.039 (2)	0.312 (11)
Br32b	0.75	0.8754 (9)	0.25	0.039 (2)	0.271 (16)
Br42a	0.25	0.7612 (7)	0.4116 (7)	0.0414 (13)	0.270 (9)
Br42b	0.25	0.7585 (7)	0.3669 (6)	0.0414 (13)	0.245 (13)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Bi11	0.0176 (19)	0.0290 (16)	0.0200 (8)	0	0	−0.0049 (10)
Bi21	0.0207 (18)	0.0306 (15)	0.0141 (7)	0	0	0.0029 (9)
Bi31	0.040 (2)	0.0227 (15)	0.0424 (11)	0	0	0.0025 (11)
Ni11	0.029 (6)	0.022 (5)	0.014 (2)	0	0	0.003 (3)
Bi12	0.023 (2)	0.0329 (17)	0.0221 (8)	0	0	−0.0037 (11)
Bi22	0.0177 (19)	0.052 (2)	0.0280 (9)	0	0	0.0106 (12)
Bi32	0.062 (3)	0.0292 (18)	0.0545 (14)	0	0	0.0126 (14)
Ni12	0.005 (5)	0.023 (5)	0.040 (3)	0	0	−0.003 (3)
Br11	0.047 (3)	0.068 (3)	0.0250 (18)	0	0	0
Bi41a	0.073 (10)	0.040 (6)	0.020 (4)	0	0	0
Bi41b	0.088 (13)	0.029 (6)	0.017 (5)	0	0	0
Br21a	0.048 (3)	0.032 (6)	0.0465 (19)	0	0	0
Br21b	0.048 (3)	0.032 (6)	0.0465 (19)	0	0	0
Br31a	0.039 (3)	0.036 (6)	0.0430 (18)	0	0	0
Br31b	0.039 (3)	0.036 (6)	0.0430 (18)	0	0	0
Br41a	0.050 (2)	0.055 (2)	0.019 (2)	0	0	−0.003 (3)
Br41b	0.050 (2)	0.055 (2)	0.019 (2)	0	0	−0.003 (3)
Br12	0.047 (3)	0.068 (3)	0.0250 (18)	0	0	0
Bi42a	0.085 (14)	0.015 (6)	0.026 (5)	0	0	0
Bi42b	0.065 (8)	0.037 (5)	0.028 (4)	0	0	0
Br22a	0.048 (3)	0.032 (6)	0.0465 (19)	0	0	0
Br22b	0.048 (3)	0.032 (6)	0.0465 (19)	0	0	0
Br32a	0.039 (3)	0.036 (6)	0.0430 (18)	0	0	0
Br32b	0.039 (3)	0.036 (6)	0.0430 (18)	0	0	0
Br42a	0.050 (2)	0.055 (2)	0.019 (2)	0	0	−0.003 (3)
Br42b	0.050 (2)	0.055 (2)	0.019 (2)	0	0	−0.003 (3)

Bond lengths (Å) top

Bi11—Bi11ⁱ	4.066	Bi41b—Br41bⁱ	3.003 (9)
Bi11—Bi11ⁱⁱ	4.066	Bi41b—Br41b	3.003 (9)
Bi11—Bi21	3.398 (3)	Bi41b—Br41b^xii	3.003 (9)
Bi11—Bi21ⁱⁱⁱ	3.616 (3)	Bi41b—Br41b^xi	3.003 (9)
Bi11—Bi21^iv	3.616 (3)	Br21a—Br21aⁱ	4.066
Bi11—Bi31	3.309 (3)	Br21a—Br21aⁱⁱ	4.066
Bi11—Bi31ⁱⁱ	3.309 (3)	Br21a—Br21bⁱ	4.101 (6)
Bi11—Ni11	2.730 (5)	Br21a—Br21bⁱⁱ	4.101 (6)
Bi11—Ni11ⁱⁱ	2.730 (5)	Br21a—Br31a	4.15 (4)
Bi11—Ni11ⁱⁱⁱ	2.843 (9)	Br21a—Br41aⁱ	4.135 (19)
Bi11—Br11ⁱⁱⁱ	3.257 (8)	Br21a—Br41a	4.135 (19)
Bi11—Br32a^v	3.871 (14)	Br21a—Br41a^xii	4.135 (19)
Bi11—Br32a^vi	3.871 (14)	Br21a—Br41a^xi	4.135 (19)
Bi11—Br32b^v	3.639 (7)	Br21a—Br41bⁱ	3.634 (18)
Bi11—Br32b^vi	3.639 (7)	Br21a—Br41b	3.634 (18)
Bi11—Br42a^v	3.886 (16)	Br21a—Br41b^xii	3.634 (18)
Bi11—Br42b^v	4.020 (16)	Br21a—Br41b^xi	3.634 (18)
Bi21—Bi21ⁱ	4.066	Br21b—Br21bⁱ	4.066
Bi21—Bi21ⁱⁱ	4.066	Br21b—Br21bⁱⁱ	4.066
Bi21—Bi31	3.247 (3)	Br21b—Br41bⁱ	3.96 (3)
Bi21—Bi31ⁱⁱ	3.247 (3)	Br21b—Br41b	3.96 (3)
Bi21—Ni11	2.778 (4)	Br21b—Br41b^xii	3.96 (3)
Bi21—Ni11ⁱⁱ	2.778 (4)	Br21b—Br41b^xi	3.96 (3)
Bi21—Ni11ⁱⁱⁱ	2.782 (8)	Br31a—Br31aⁱ	4.066
Bi21—Br11	3.403 (6)	Br31a—Br31aⁱⁱ	4.066
Bi21—Br11ⁱⁱ	3.403 (6)	Br31a—Br41aⁱ	4.103 (18)
Bi21—Br21b	3.90 (2)	Br31a—Br41a	4.103 (18)
Bi21—Br21bⁱⁱ	3.90 (2)	Br31a—Br41a^xii	4.103 (18)
Bi31—Bi31ⁱ	4.066	Br31a—Br41a^xi	4.103 (18)
Bi31—Bi31ⁱⁱ	4.066	Br31a—Br41bⁱ	3.662 (17)
Bi31—Ni11	2.681 (10)	Br31a—Br41b	3.662 (17)
Bi31—Br21a	3.905 (5)	Br31a—Br41b^xii	3.662 (17)
Bi31—Br21b	3.845 (3)	Br31a—Br41b^xi	3.662 (17)
Bi31—Br41aⁱ	3.586 (16)	Br31a—Br12ⁱ	4.02 (3)
Bi31—Br41a	3.586 (16)	Br31a—Br12	4.02 (3)
Bi31—Br41bⁱ	3.790 (12)	Br31b—Br31bⁱ	4.066
Bi31—Br41b	3.790 (12)	Br31b—Br31bⁱⁱ	4.066
Bi31—Br42a^vii	3.557 (12)	Br31b—Br12ⁱ	3.14 (3)
Bi31—Br42a^v	3.557 (12)	Br31b—Br12	3.14 (3)
Bi31—Br42b^vii	4.064 (11)	Br41a—Br41aⁱ	4.066
Bi31—Br42b^v	4.064 (11)	Br41a—Br41aⁱⁱ	4.066
Ni11—Ni11ⁱ	4.066	Br41a—Br41bⁱ	4.128 (3)
Ni11—Ni11ⁱⁱ	4.066	Br41a—Br41bⁱⁱ	4.128 (3)
Ni11—Ni11^viii	2.523 (8)	Br41a—Br42a^v	2.945 (18)
Ni11—Ni11ⁱⁱⁱ	2.523 (8)	Br41a—Br42b^v	3.687 (16)
Bi12—Bi12ⁱ	4.066	Br41b—Br41bⁱ	4.066
Bi12—Bi12ⁱⁱ	4.066	Br41b—Br41bⁱⁱ	4.066
Bi12—Bi22	3.425 (3)	Br41b—Br42a^v	3.635 (17)
Bi12—Bi22^v	3.571 (4)	Br12—Br12ⁱ	4.066
Bi12—Bi22^vi	3.571 (4)	Br12—Br12ⁱⁱ	4.066
Bi12—Bi32	3.318 (3)	Br12—Br22a	3.89 (3)
Bi12—Bi32ⁱⁱ	3.318 (3)	Br12—Br22b	2.97 (3)
Bi12—Ni12	2.745 (5)	Bi42a—Bi42aⁱ	4.066
Bi12—Ni12ⁱⁱ	2.745 (5)	Bi42a—Bi42aⁱⁱ	4.066
Bi12—Ni12^v	2.784 (9)	Bi42a—Br22aⁱ	2.960 (15)
Bi12—Br31a	3.859 (11)	Bi42a—Br22a	2.960 (15)
Bi12—Br31aⁱⁱ	3.859 (11)	Bi42a—Br22bⁱ	3.68 (2)
Bi12—Br31b	3.512 (5)	Bi42a—Br22b	3.68 (2)
Bi12—Br31bⁱⁱ	3.512 (5)	Bi42a—Br32aⁱ	2.91 (2)
Bi12—Br41a	3.78 (2)	Bi42a—Br32a	2.91 (2)
Bi12—Br41b	3.875 (14)	Bi42a—Br32bⁱ	3.344 (18)
Bi12—Br12	3.277 (13)	Bi42a—Br32b	3.344 (18)
Bi22—Bi22ⁱ	4.066	Bi42a—Br42a	2.769 (12)
Bi22—Bi22ⁱⁱ	4.066	Bi42a—Br42a^xii	2.769 (12)
Bi22—Bi32	3.250 (4)	Bi42b—Bi42bⁱ	4.066
Bi22—Bi32ⁱⁱ	3.250 (4)	Bi42b—Bi42bⁱⁱ	4.066
Bi22—Ni12	2.771 (5)	Bi42b—Br22b	2.98 (3)
Bi22—Ni12ⁱⁱ	2.771 (5)	Bi42b—Br32b	2.75 (2)
Bi22—Ni12^v	2.792 (9)	Bi42b—Br42a	3.436 (10)
Bi22—Br12^v	3.348 (9)	Bi42b—Br42aⁱⁱ	3.436 (10)
Bi22—Br12^vi	3.348 (9)	Bi42b—Br42a^xii	3.436 (10)
Bi22—Br22a^v	4.139 (13)	Bi42b—Br42a^xi	3.436 (10)
Bi22—Br22a^vi	4.139 (13)	Bi42b—Br42b	2.854 (7)
Bi22—Br22b^v	3.606 (12)	Bi42b—Br42bⁱⁱ	2.854 (7)
Bi22—Br22b^vi	3.606 (12)	Bi42b—Br42b^xii	2.854 (7)
Bi32—Bi32ⁱ	4.066	Bi42b—Br42b^xi	2.854 (7)
Bi32—Bi32ⁱⁱ	4.066	Br22a—Br22aⁱ	4.066
Bi32—Ni12	2.665 (10)	Br22a—Br22aⁱⁱ	4.066
Bi32—Br41aⁱ	3.465 (14)	Br22a—Br22bⁱ	4.169 (7)
Bi32—Br41a	3.465 (14)	Br22a—Br22bⁱⁱ	4.169 (7)
Bi32—Br41bⁱ	3.927 (11)	Br22a—Br42a	4.050 (16)
Bi32—Br41b	3.927 (11)	Br22a—Br42aⁱⁱ	4.050 (16)
Bi32—Br22a^v	3.817 (4)	Br22a—Br42a^xii	4.050 (16)
Bi32—Br22b^v	3.787 (4)	Br22a—Br42a^xi	4.050 (16)
Bi32—Br42a^vii	3.549 (13)	Br22a—Br42b	3.533 (16)
Bi32—Br42a^v	3.549 (13)	Br22a—Br42bⁱⁱ	3.533 (16)
Bi32—Br42b^vii	3.792 (13)	Br22a—Br42b^xii	3.533 (16)
Bi32—Br42b^v	3.792 (13)	Br22a—Br42b^xi	3.533 (16)
Ni12—Ni12ⁱ	4.066	Br22b—Br22bⁱ	4.066
Ni12—Ni12ⁱⁱ	4.066	Br22b—Br22bⁱⁱ	4.066
Ni12—Ni12^vii	2.505 (8)	Br22b—Br42b	4.14 (2)
Ni12—Ni12^v	2.505 (8)	Br22b—Br42bⁱⁱ	4.14 (2)
Br11—Br11ⁱ	4.066	Br22b—Br42b^xii	4.14 (2)
Br11—Br11ⁱⁱ	4.066	Br22b—Br42b^xi	4.14 (2)
Br11—Br21a	4.05 (3)	Br32a—Br32aⁱ	4.066
Br11—Br21b	3.51 (4)	Br32a—Br32aⁱⁱ	4.066
Br11—Br32a^ix	4.08 (3)	Br32a—Br32bⁱ	4.107 (5)
Br11—Br32a^x	4.08 (3)	Br32a—Br32bⁱⁱ	4.107 (5)
Br11—Br32b^ix	3.59 (2)	Br32a—Br42a	4.017 (19)
Br11—Br32b^x	3.59 (2)	Br32a—Br42aⁱⁱ	4.017 (19)
Bi41a—Bi41aⁱ	4.066	Br32a—Br42a^xii	4.017 (19)
Bi41a—Bi41aⁱⁱ	4.066	Br32a—Br42a^xi	4.017 (19)
Bi41a—Br21a	2.88 (2)	Br32a—Br42b	3.57 (2)
Bi41a—Br21aⁱⁱ	2.88 (2)	Br32a—Br42bⁱⁱ	3.57 (2)
Bi41a—Br21b	3.28 (3)	Br32a—Br42b^xii	3.57 (2)
Bi41a—Br21bⁱⁱ	3.28 (3)	Br32a—Br42b^xi	3.57 (2)
Bi41a—Br31a	2.926 (18)	Br32b—Br32bⁱ	4.066
Bi41a—Br31aⁱⁱ	2.926 (18)	Br32b—Br32bⁱⁱ	4.066
Bi41a—Br31b	3.76 (2)	Br32b—Br42b	3.944 (19)
Bi41a—Br31bⁱⁱ	3.76 (2)	Br32b—Br42bⁱⁱ	3.944 (19)
Bi41a—Br41a	2.922 (13)	Br32b—Br42b^xii	3.944 (19)
Bi41a—Br41a^xi	2.922 (13)	Br32b—Br42b^xi	3.944 (19)
Bi41b—Bi41bⁱ	4.066	Br42a—Br42aⁱ	4.066
Bi41b—Bi41bⁱⁱ	4.066	Br42a—Br42aⁱⁱ	4.066
Bi41b—Br21b	2.67 (4)	Br42a—Br42bⁱ	4.138 (3)
Bi41b—Br31b	3.07 (3)	Br42a—Br42bⁱⁱ	4.138 (3)
Bi41b—Br41aⁱ	3.559 (10)	Br42b—Br42bⁱ	4.066
Bi41b—Br41a	3.559 (10)	Br42b—Br42bⁱⁱ	4.066
Bi41b—Br41a^xii	3.559 (10)	Br42b—Br42b^xii	4.005 (14)
Bi41b—Br41a^xi	3.559 (10)

Symmetry codes: (i) x−1, y, z; (ii) x+1, y, z; (iii) −x+1, −y, −z+1; (iv) −x+2, −y, −z+1; (v) −x+1, −y+1, −z+1; (vi) −x+2, −y+1, −z+1; (vii) −x, −y+1, −z+1; (viii) −x, −y, −z+1; (ix) x−1, y−1, z; (x) x, y−1, z; (xi) −x+3/2, y, −z+1/2; (xii) −x+1/2, y, −z+1/2.

(Bi7Ni2Br5mod) top

Crystal data top

Bi_6.889Br_4.778Ni₂	F(000) = 3183
M_r = 1938.8	D_x = 7.941 Mg m⁻³
Orthorhombic, Xmnm(α00)00s†	Mo Kα radiation, λ = 0.71073 Å
q = 0.11111a*	Cell parameters from 14269 reflections
a = 4.0660 (4) Å	θ = 1.8–24.5°
b = 46.610 (5) Å	µ = 88.43 mm⁻¹
c = 17.1299 (15) Å	T = 293 K
V = 3246.4 (5) Å³	Needle, black
Z = 8	0.6 × 0.08 × 0.02 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) 1/2+x₁, −x₂, 1/2+x₃, x₄; (3) x₁, x₂, 1/2−x₃, x₄; (4) 1/2+x₁, −x₂, −x₃, x₄; (5) −x₁, −x₂, −x₃, −x₄; (6) 1/2−x₁, x₂, 1/2−x₃, −x₄; (7) −x₁, −x₂, 1/2+x₃, −x₄; (8) 1/2−x₁, x₂, x₃, −x₄; (9) x₁, 1/2+x₂, x₃, 1/2+x₄; (10) 1/2+x₁, 1/2−x₂, 1/2+x₃, 1/2+x₄; (11) x₁, 1/2+x₂, 1/2−x₃, 1/2+x₄; (12) 1/2+x₁, 1/2−x₂, −x₃, 1/2+x₄; (13) −x₁, 1/2−x₂, −x₃, 1/2−x₄; (14) 1/2−x₁, 1/2+x₂, 1/2−x₃, 1/2−x₄; (15) −x₁, 1/2−x₂, 1/2+x₃, 1/2−x₄; (16) 1/2−x₁, 1/2+x₂, x₃, 1/2−x₄.

Data collection top

Imaging plate diffractometer STOE IPDS II	7264 independent reflections
Radiation source: fine-focus sealed tube	2724 reflections with I > 3σ(I)
Graphite monochromator	R_int = 0.150
incremental rotation scans	θ_max = 24.6°, θ_min = 1.4°
Absorption correction: numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	h = −4→4
T_min = 0.02, T_max = 0.204	k = −54→54
84857 measured reflections	l = −20→20

Refinement top

Refinement on F²	213 parameters
R[F² > 2σ(F²)] = 0.070	Weighting scheme based on measured s.u.'s w = 1/(σ²(I) + 0.000025I²)
wR(F²) = 0.090	(Δ/σ)_max = 0.001
S = 3.18	Δρ_max = 9.13 e Å⁻³
7264 reflections	Δρ_min = −9.18 e Å⁻³

Crystal data top

Bi_6.889Br_4.778Ni₂	V = 3246.4 (5) Å³
M_r = 1938.8	Z = 8
Orthorhombic, Xmnm(α00)00s†	Mo Kα radiation
q = 0.11111a*	µ = 88.43 mm⁻¹
a = 4.0660 (4) Å	T = 293 K
b = 46.610 (5) Å	0.6 × 0.08 × 0.02 mm
c = 17.1299 (15) Å

Data collection top

Imaging plate diffractometer STOE IPDS II	7264 independent reflections
Absorption correction: numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	2724 reflections with I > 3σ(I)
T_min = 0.02, T_max = 0.204	R_int = 0.150
84857 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.070	213 parameters
wR(F²) = 0.090	Δρ_max = 9.13 e Å⁻³
S = 3.18	Δρ_min = −9.18 e Å⁻³
7264 reflections

Special details top

Refinement. The starting model for the refinement of the superstructure is based on crystal chemical considerations. Due to high correlations several restraints were applied in the refinement. The fourier maps show that the electron density is described well by the proposed modulation model.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Bi11	0.75	0.03594 (3)	0.58915 (5)	0.0211 (4)
Bi21	0.75	0.02775 (3)	0.39177 (5)	0.0207 (4)
Bi31	0.25	0.07282 (4)	0.47440 (7)	0.0339 (5)
Ni11	0.25	0.01602 (11)	0.49796 (18)	0.0212 (3)
Bi12	0.75	0.21399 (3)	0.41278 (6)	0.0246 (4)
Bi22	0.75	0.22365 (4)	0.61083 (6)	0.0273 (4)
Bi32	0.25	0.17796 (4)	0.53016 (7)	0.0419 (6)
Ni12	0.25	0.23442 (11)	0.50508 (18)	0.0212 (3)
Br11	0.25	0.00132 (14)	0.25	0.0375 (19)
Bi41a	0.75	0.13189 (6)	0.25	0.0279 (9)
Bi41b	0.25	0.13428 (8)	0.25	0.0233 (15)
Br21a	0.25	0.08685 (19)	0.25	0.046 (2)
Br21b	0.25	0.0761 (3)	0.25	0.046 (2)
Br31a	0.25	0.17822 (19)	0.25	0.045 (3)
Br31b	0.25	0.1999 (2)	0.25	0.045 (3)
Br41a	0.75	0.13176 (15)	0.4127 (3)	0.0453 (16)
Br41b	0.75	0.13313 (19)	0.3729 (4)	0.0453 (16)
Br12	0.75	0.2509 (2)	0.25	0.035 (3)
Bi42a	0.25	0.38047 (7)	0.25	0.0251 (12)
Bi42b	0.75	0.37836 (7)	0.25	0.0282 (11)
Br22a	0.75	0.3349 (2)	0.25	0.0330 (19)
Br22b	0.75	0.3156 (2)	0.25	0.0330 (19)
Br32a	0.75	0.42474 (18)	0.25	0.0246 (15)
Br32b	0.75	0.43808 (19)	0.25	0.0246 (15)
Br42a	0.25	0.38159 (17)	0.4170 (3)	0.0362 (15)
Br42b	0.25	0.37878 (13)	0.3726 (3)	0.0362 (15)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Bi11	0.0173 (8)	0.0283 (8)	0.0176 (4)	0	0	−0.0026 (5)
Bi21	0.0176 (8)	0.0314 (7)	0.0132 (4)	0	0	0.0039 (5)
Bi31	0.0432 (12)	0.0227 (8)	0.0357 (5)	0	0	0.0036 (6)
Ni11	0.0154 (6)	0.0232 (7)	0.0251 (5)	0	0	0.0009 (5)
Bi12	0.0219 (9)	0.0290 (8)	0.0229 (4)	0	0	−0.0054 (5)
Bi22	0.0208 (9)	0.0335 (9)	0.0275 (5)	0	0	0.0059 (6)
Bi32	0.0554 (15)	0.0248 (9)	0.0454 (6)	0	0	0.0044 (7)
Ni12	0.0154 (6)	0.0232 (7)	0.0251 (5)	0	0	0.0009 (5)
Br11	0.047 (4)	0.043 (4)	0.0226 (16)	0	0	0
Bi41a	0.028 (2)	0.0340 (17)	0.0214 (9)	0	0	0
Bi41b	0.026 (4)	0.0248 (19)	0.0194 (13)	0	0	0
Br21a	0.048 (5)	0.023 (4)	0.066 (3)	0	0	0
Br21b	0.048 (5)	0.023 (4)	0.066 (3)	0	0	0
Br31a	0.052 (5)	0.019 (5)	0.065 (3)	0	0	0
Br31b	0.052 (5)	0.019 (5)	0.065 (3)	0	0	0
Br41a	0.052 (3)	0.053 (3)	0.0312 (18)	0	0	0.0013 (17)
Br41b	0.052 (3)	0.053 (3)	0.0312 (18)	0	0	0.0013 (17)
Br12	0.040 (6)	0.042 (5)	0.023 (3)	0	0	0
Bi42a	0.026 (3)	0.0229 (18)	0.0267 (12)	0	0	0
Bi42b	0.031 (3)	0.0301 (16)	0.0234 (11)	0	0	0
Br22a	0.033 (3)	0.039 (4)	0.0272 (17)	0	0	0
Br22b	0.033 (3)	0.039 (4)	0.0272 (17)	0	0	0
Br32a	0.017 (3)	0.034 (3)	0.0230 (15)	0	0	0
Br32b	0.017 (3)	0.034 (3)	0.0230 (15)	0	0	0
Br42a	0.036 (3)	0.052 (3)	0.0207 (17)	0	0	0.0016 (16)
Br42b	0.036 (3)	0.052 (3)	0.0207 (17)	0	0	0.0016 (16)

(Bi7Ni2Br5simplified) top

Crystal data top

Bi_6.889Br_4.778Ni₂	F(000) = 3183
M_r = 1938.8	D_x = 7.941 Mg m⁻³
Orthorhombic, Cmcm	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C -2zc;-2x	Cell parameters from 14269 reflections
a = 4.0660 (4) Å	θ = 1.8–24.5°
b = 23.305 (3) Å	µ = 88.43 mm⁻¹
c = 17.130 (2) Å	T = 293 K
V = 1623.2 (3) Å³	Needle, black
Z = 4	0.6 × 0.08 × 0.02 mm

Data collection top

Imaging plate diffractometer STOE IPDS II	815 independent reflections
Radiation source: fine-focus sealed tube	752 reflections with I > 3σ(I)
Graphite monochromator	R_int = 0.103
incremental rotation scans	θ_max = 24.5°, θ_min = 1.8°
Absorption correction: numerical microscopic crystal description optimized with X-SHAPE 1.06 (Stoe, 1999)	h = −4→4
T_min = 0.02, T_max = 0.204	k = −26→26
8504 measured reflections	l = −19→19

Refinement top

Refinement on F²	56 parameters
R[F² > 2σ(F²)] = 0.039	Weighting scheme based on measured s.u.'s w = 1/(σ²(I) + 0.000025I²)
wR(F²) = 0.078	(Δ/σ)_max = 0.0004
S = 7.85	Δρ_max = 2.92 e Å⁻³
815 reflections	Δρ_min = −3.05 e Å⁻³

Crystal data top

Bi_6.889Br_4.778Ni₂	V = 1623.2 (3) Å³
M_r = 1938.8	Z = 4
Orthorhombic, Cmcm	Mo Kα radiation
a = 4.0660 (4) Å	µ = 88.43 mm⁻¹
b = 23.305 (3) Å	T = 293 K
c = 17.130 (2) Å	0.6 × 0.08 × 0.02 mm

Data collection top

Imaging plate diffractometer STOE IPDS II	815 independent reflections
Absorption correction: numerical microscopic crystal description optimized with X-SHAPE 1.06 (Stoe, 1999)	752 reflections with I > 3σ(I)
T_min = 0.02, T_max = 0.204	R_int = 0.103
8504 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.039	56 parameters
wR(F²) = 0.078	Δρ_max = 2.92 e Å⁻³
S = 7.85	Δρ_min = −3.05 e Å⁻³
815 reflections

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Bi1	0.5	0.32190 (5)	0.41176 (5)	0.0240 (3)
Bi2	0.5	0.30445 (5)	0.60932 (5)	0.0271 (3)
Bi3	0	0.39502 (6)	0.52761 (7)	0.0417 (4)
Ni	0	0.28158 (15)	0.50355 (15)	0.0214 (9)
Br1	0.5	0.2476 (3)	0.25	0.047 (2)	0.82 (2)
Bi4a	0.5	0.48744 (16)	0.25	0.0449 (11)	0.502 (7)
Bi4b	0	0.4880 (2)	0.25	0.0449 (11)	0.381 (6)
Br2a	0	0.3945 (4)	0.25	0.048 (2)	0.732 (10)
Br2b	0	0.3585 (12)	0.25	0.048 (2)	0.268 (10)
Br3a	0	0.5804 (4)	0.25	0.051 (2)	0.732 (10)
Br3b	0	0.6156 (12)	0.25	0.051 (2)	0.268 (10)
Br4a	0.5	0.4866 (3)	0.4150 (4)	0.0456 (15)	0.5
Br4b	0.5	0.4888 (3)	0.3726 (4)	0.0456 (15)	0.5

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Bi1	0.0201 (5)	0.0309 (6)	0.0211 (4)	0	0	0.0041 (4)
Bi2	0.0194 (6)	0.0408 (7)	0.0211 (4)	0	0	−0.0068 (4)
Bi3	0.0496 (8)	0.0262 (6)	0.0493 (6)	0	0	−0.0077 (5)
Ni	0.0158 (16)	0.0222 (17)	0.0261 (13)	0	0	−0.0002 (13)
Br1	0.048 (4)	0.068 (5)	0.026 (3)	0	0	0
Bi4a	0.077 (2)	0.0353 (17)	0.0225 (13)	0	0	0
Bi4b	0.077 (2)	0.0353 (17)	0.0225 (13)	0	0	0
Br2a	0.037 (4)	0.068 (6)	0.040 (2)	0	0	0
Br2b	0.037 (4)	0.068 (6)	0.040 (2)	0	0	0
Br3a	0.047 (4)	0.060 (5)	0.046 (2)	0	0	0
Br3b	0.047 (4)	0.060 (5)	0.046 (2)	0	0	0
Br4a	0.050 (3)	0.058 (3)	0.028 (3)	0	0	−0.003 (3)
Br4b	0.050 (3)	0.058 (3)	0.028 (3)	0	0	−0.003 (3)

Bond lengths (Å) top

Bi1—Bi2	3.4086 (12)	Br1—Br2a	3.980 (10)
Bi1—Bi2ⁱ	3.5965 (13)	Br1—Br2aⁱⁱⁱ	3.980 (10)
Bi1—Bi2ⁱⁱ	3.5965 (13)	Br1—Br2b	3.29 (2)
Bi1—Bi3	3.3128 (12)	Br1—Br2bⁱⁱⁱ	3.29 (2)
Bi1—Bi3ⁱⁱⁱ	3.3128 (12)	Br1—Br3a^viii	3.897 (12)
Bi1—Ni	2.737 (2)	Br1—Br3b^viii	3.08 (3)
Bi1—Niⁱⁱⁱ	2.737 (2)	Bi4a—Br2a	2.971 (8)
Bi1—Niⁱ	2.814 (3)	Bi4a—Br2aⁱⁱⁱ	2.971 (8)
Bi1—Br1	3.267 (4)	Bi4a—Br2b	3.63 (2)
Bi1—Br2a	3.830 (4)	Bi4a—Br2bⁱⁱⁱ	3.63 (2)
Bi1—Br2aⁱⁱⁱ	3.830 (4)	Bi4a—Br3a	2.971 (7)
Bi1—Br2b	3.541 (7)	Bi4a—Br3aⁱⁱⁱ	2.971 (7)
Bi1—Br2bⁱⁱⁱ	3.541 (7)	Bi4a—Br3b	3.61 (2)
Bi1—Br4a	3.839 (8)	Bi4a—Br3bⁱⁱⁱ	3.61 (2)
Bi1—Br4b	3.946 (8)	Bi4a—Br4a	2.826 (7)
Bi2—Bi3	3.2477 (13)	Bi4a—Br4a^ix	2.826 (7)
Bi2—Bi3ⁱⁱⁱ	3.2477 (13)	Bi4b—Br2b	3.02 (3)
Bi2—Ni	2.7749 (19)	Bi4b—Br3b	2.97 (3)
Bi2—Niⁱⁱⁱ	2.7749 (19)	Bi4b—Br4a^vi	3.481 (5)
Bi2—Niⁱ	2.785 (3)	Bi4b—Br4a	3.481 (5)
Bi2—Br1ⁱ	3.378 (3)	Bi4b—Br4a^x	3.481 (5)
Bi2—Br1ⁱⁱ	3.378 (3)	Bi4b—Br4a^ix	3.481 (5)
Bi2—Br3b^iv	3.663 (14)	Bi4b—Br4b^vi	2.923 (5)
Bi2—Br3b^v	3.663 (14)	Bi4b—Br4b	2.923 (5)
Bi3—Ni	2.676 (4)	Bi4b—Br4b^x	2.923 (5)
Bi3—Br3a^iv	3.8525 (18)	Bi4b—Br4b^ix	2.923 (5)
Bi3—Br3b^iv	3.818 (2)	Br2a—Br4b^vi	3.657 (8)
Bi3—Br4a^vi	3.523 (6)	Br2a—Br4b	3.657 (8)
Bi3—Br4a	3.523 (6)	Br2a—Br4b^x	3.657 (8)
Bi3—Br4a^iv	3.565 (6)	Br2a—Br4b^ix	3.657 (8)
Bi3—Br4a^v	3.565 (6)	Br3a—Br4b^vi	3.620 (8)
Bi3—Br4b^vi	3.994 (6)	Br3a—Br4b	3.620 (8)
Bi3—Br4b	3.994 (6)	Br3a—Br4b^x	3.620 (8)
Bi3—Br4b^iv	3.794 (6)	Br3a—Br4b^ix	3.620 (8)
Bi3—Br4b^v	3.794 (6)	Br4a—Br4a^v	2.979 (9)
Ni—Ni^vii	2.513 (3)	Br4a—Br4b^v	3.684 (9)
Ni—Niⁱ	2.513 (3)

Symmetry codes: (i) −x+1/2, −y+1/2, −z+1; (ii) −x+3/2, −y+1/2, −z+1; (iii) x+1, y, z; (iv) −x, −y+1, −z+1; (v) −x+1, −y+1, −z+1; (vi) x−1, y, z; (vii) −x−1/2, −y+1/2, −z+1; (viii) x+1/2, y−1/2, z; (ix) x, y, −z+1/2; (x) x−1, y, −z+1/2.

Experimental details

	(Bi7Ni2Br5average)	(Bi7Ni2Br5mod)	(Bi7Ni2Br5simplified)
Crystal data
Chemical formula	Bi_6.889Br_4.778Ni₂	Bi_6.889Br_4.778Ni₂	Bi_6.889Br_4.778Ni₂
M_r	1938.8	1938.8	1938.8
Crystal system, space group	Orthorhombic, Pmnm	Orthorhombic, Xmnm(α00)00s†	Orthorhombic, Cmcm
Temperature (K)	293	293	293
a, b, c (Å)	4.0660 (4), 23.305 (3), 17.130 (2)	?	4.0660 (4), 23.305 (3), 17.130 (2)
V (Å³)	1623.2 (3)	90, 90, 90	1623.2 (3)
Z	4	3246.4 (5)	4
Radiation type	Mo Kα	?	Mo Kα
µ (mm⁻¹)	88.43	1.8–24.5	88.43
Crystal size (mm)	0.6 × 0.08 × 0.02	Black	0.6 × 0.08 × 0.02

Data collection
Diffractometer	Imaging plate diffractometer STOE IPDS II	Imaging plate diffractometer STOE IPDS II	Imaging plate diffractometer STOE IPDS II
Absorption correction	Numerical microscopic crystal description optimized with X-SHAPE 1.06 (Stoe, 1999)	Numerical (Jana2000; Petricek, Dusek & Palatinus, 2000)	Numerical microscopic crystal description optimized with X-SHAPE 1.06 (Stoe, 1999)
T_min, T_max	0.02, 0.204	0.02, 0.204	0.02, 0.204
No. of measured, independent and observed [I > 3σ(I)] reflections	17051, 1631, 1075	84857, 7264, 2724	8504, 815, 752
R_int	0.114	0.150	0.103
(sin θ/λ)_max (Å⁻¹)	0.586	0.586	0.584

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.060, 0.085, 6.06	0.070, 0.090, 3.18	0.039, 0.078, 7.85
No. of reflections	1631	7264	815
No. of parameters	105	213	56
No. of restraints	?	?	?
Δρ_max, Δρ_min (e Å⁻³)	2.17, −2.30	9.13, −9.18	2.92, −3.05

Computer programs: (Jana2000; Petricek and Dusek, 2000).

Selected bond lengths (Å) for (Bi7Ni2Br5average) top

Bi11—Bi11ⁱ	4.066	Bi41b—Br41bⁱ	3.003 (9)
Bi11—Bi11ⁱⁱ	4.066	Bi41b—Br41b	3.003 (9)
Bi11—Bi21	3.398 (3)	Bi41b—Br41b^xii	3.003 (9)
Bi11—Bi21ⁱⁱⁱ	3.616 (3)	Bi41b—Br41b^xi	3.003 (9)
Bi11—Bi21^iv	3.616 (3)	Br21a—Br21aⁱ	4.066
Bi11—Bi31	3.309 (3)	Br21a—Br21aⁱⁱ	4.066
Bi11—Bi31ⁱⁱ	3.309 (3)	Br21a—Br21bⁱ	4.101 (6)
Bi11—Ni11	2.730 (5)	Br21a—Br21bⁱⁱ	4.101 (6)
Bi11—Ni11ⁱⁱ	2.730 (5)	Br21a—Br31a	4.15 (4)
Bi11—Ni11ⁱⁱⁱ	2.843 (9)	Br21a—Br41aⁱ	4.135 (19)
Bi11—Br11ⁱⁱⁱ	3.257 (8)	Br21a—Br41a	4.135 (19)
Bi11—Br32a^v	3.871 (14)	Br21a—Br41a^xii	4.135 (19)
Bi11—Br32a^vi	3.871 (14)	Br21a—Br41a^xi	4.135 (19)
Bi11—Br32b^v	3.639 (7)	Br21a—Br41bⁱ	3.634 (18)
Bi11—Br32b^vi	3.639 (7)	Br21a—Br41b	3.634 (18)
Bi11—Br42a^v	3.886 (16)	Br21a—Br41b^xii	3.634 (18)
Bi11—Br42b^v	4.020 (16)	Br21a—Br41b^xi	3.634 (18)
Bi21—Bi21ⁱ	4.066	Br21b—Br21bⁱ	4.066
Bi21—Bi21ⁱⁱ	4.066	Br21b—Br21bⁱⁱ	4.066
Bi21—Bi31	3.247 (3)	Br21b—Br41bⁱ	3.96 (3)
Bi21—Bi31ⁱⁱ	3.247 (3)	Br21b—Br41b	3.96 (3)
Bi21—Ni11	2.778 (4)	Br21b—Br41b^xii	3.96 (3)
Bi21—Ni11ⁱⁱ	2.778 (4)	Br21b—Br41b^xi	3.96 (3)
Bi21—Ni11ⁱⁱⁱ	2.782 (8)	Br31a—Br31aⁱ	4.066
Bi21—Br11	3.403 (6)	Br31a—Br31aⁱⁱ	4.066
Bi21—Br11ⁱⁱ	3.403 (6)	Br31a—Br41aⁱ	4.103 (18)
Bi21—Br21b	3.90 (2)	Br31a—Br41a	4.103 (18)
Bi21—Br21bⁱⁱ	3.90 (2)	Br31a—Br41a^xii	4.103 (18)
Bi31—Bi31ⁱ	4.066	Br31a—Br41a^xi	4.103 (18)
Bi31—Bi31ⁱⁱ	4.066	Br31a—Br41bⁱ	3.662 (17)
Bi31—Ni11	2.681 (10)	Br31a—Br41b	3.662 (17)
Bi31—Br21a	3.905 (5)	Br31a—Br41b^xii	3.662 (17)
Bi31—Br21b	3.845 (3)	Br31a—Br41b^xi	3.662 (17)
Bi31—Br41aⁱ	3.586 (16)	Br31a—Br12ⁱ	4.02 (3)
Bi31—Br41a	3.586 (16)	Br31a—Br12	4.02 (3)
Bi31—Br41bⁱ	3.790 (12)	Br31b—Br31bⁱ	4.066
Bi31—Br41b	3.790 (12)	Br31b—Br31bⁱⁱ	4.066
Bi31—Br42a^vii	3.557 (12)	Br31b—Br12ⁱ	3.14 (3)
Bi31—Br42a^v	3.557 (12)	Br31b—Br12	3.14 (3)
Bi31—Br42b^vii	4.064 (11)	Br41a—Br41aⁱ	4.066
Bi31—Br42b^v	4.064 (11)	Br41a—Br41aⁱⁱ	4.066
Ni11—Ni11ⁱ	4.066	Br41a—Br41bⁱ	4.128 (3)
Ni11—Ni11ⁱⁱ	4.066	Br41a—Br41bⁱⁱ	4.128 (3)
Ni11—Ni11^viii	2.523 (8)	Br41a—Br42a^v	2.945 (18)
Ni11—Ni11ⁱⁱⁱ	2.523 (8)	Br41a—Br42b^v	3.687 (16)
Bi12—Bi12ⁱ	4.066	Br41b—Br41bⁱ	4.066
Bi12—Bi12ⁱⁱ	4.066	Br41b—Br41bⁱⁱ	4.066
Bi12—Bi22	3.425 (3)	Br41b—Br42a^v	3.635 (17)
Bi12—Bi22^v	3.571 (4)	Br12—Br12ⁱ	4.066
Bi12—Bi22^vi	3.571 (4)	Br12—Br12ⁱⁱ	4.066
Bi12—Bi32	3.318 (3)	Br12—Br22a	3.89 (3)
Bi12—Bi32ⁱⁱ	3.318 (3)	Br12—Br22b	2.97 (3)
Bi12—Ni12	2.745 (5)	Bi42a—Bi42aⁱ	4.066
Bi12—Ni12ⁱⁱ	2.745 (5)	Bi42a—Bi42aⁱⁱ	4.066
Bi12—Ni12^v	2.784 (9)	Bi42a—Br22aⁱ	2.960 (15)
Bi12—Br31a	3.859 (11)	Bi42a—Br22a	2.960 (15)
Bi12—Br31aⁱⁱ	3.859 (11)	Bi42a—Br22bⁱ	3.68 (2)
Bi12—Br31b	3.512 (5)	Bi42a—Br22b	3.68 (2)
Bi12—Br31bⁱⁱ	3.512 (5)	Bi42a—Br32aⁱ	2.91 (2)
Bi12—Br41a	3.78 (2)	Bi42a—Br32a	2.91 (2)
Bi12—Br41b	3.875 (14)	Bi42a—Br32bⁱ	3.344 (18)
Bi12—Br12	3.277 (13)	Bi42a—Br32b	3.344 (18)
Bi22—Bi22ⁱ	4.066	Bi42a—Br42a	2.769 (12)
Bi22—Bi22ⁱⁱ	4.066	Bi42a—Br42a^xii	2.769 (12)
Bi22—Bi32	3.250 (4)	Bi42b—Bi42bⁱ	4.066
Bi22—Bi32ⁱⁱ	3.250 (4)	Bi42b—Bi42bⁱⁱ	4.066
Bi22—Ni12	2.771 (5)	Bi42b—Br22b	2.98 (3)
Bi22—Ni12ⁱⁱ	2.771 (5)	Bi42b—Br32b	2.75 (2)
Bi22—Ni12^v	2.792 (9)	Bi42b—Br42a	3.436 (10)
Bi22—Br12^v	3.348 (9)	Bi42b—Br42aⁱⁱ	3.436 (10)
Bi22—Br12^vi	3.348 (9)	Bi42b—Br42a^xii	3.436 (10)
Bi22—Br22a^v	4.139 (13)	Bi42b—Br42a^xi	3.436 (10)
Bi22—Br22a^vi	4.139 (13)	Bi42b—Br42b	2.854 (7)
Bi22—Br22b^v	3.606 (12)	Bi42b—Br42bⁱⁱ	2.854 (7)
Bi22—Br22b^vi	3.606 (12)	Bi42b—Br42b^xii	2.854 (7)
Bi32—Bi32ⁱ	4.066	Bi42b—Br42b^xi	2.854 (7)
Bi32—Bi32ⁱⁱ	4.066	Br22a—Br22aⁱ	4.066
Bi32—Ni12	2.665 (10)	Br22a—Br22aⁱⁱ	4.066
Bi32—Br41aⁱ	3.465 (14)	Br22a—Br22bⁱ	4.169 (7)
Bi32—Br41a	3.465 (14)	Br22a—Br22bⁱⁱ	4.169 (7)
Bi32—Br41bⁱ	3.927 (11)	Br22a—Br42a	4.050 (16)
Bi32—Br41b	3.927 (11)	Br22a—Br42aⁱⁱ	4.050 (16)
Bi32—Br22a^v	3.817 (4)	Br22a—Br42a^xii	4.050 (16)
Bi32—Br22b^v	3.787 (4)	Br22a—Br42a^xi	4.050 (16)
Bi32—Br42a^vii	3.549 (13)	Br22a—Br42b	3.533 (16)
Bi32—Br42a^v	3.549 (13)	Br22a—Br42bⁱⁱ	3.533 (16)
Bi32—Br42b^vii	3.792 (13)	Br22a—Br42b^xii	3.533 (16)
Bi32—Br42b^v	3.792 (13)	Br22a—Br42b^xi	3.533 (16)
Ni12—Ni12ⁱ	4.066	Br22b—Br22bⁱ	4.066
Ni12—Ni12ⁱⁱ	4.066	Br22b—Br22bⁱⁱ	4.066
Ni12—Ni12^vii	2.505 (8)	Br22b—Br42b	4.14 (2)
Ni12—Ni12^v	2.505 (8)	Br22b—Br42bⁱⁱ	4.14 (2)
Br11—Br11ⁱ	4.066	Br22b—Br42b^xii	4.14 (2)
Br11—Br11ⁱⁱ	4.066	Br22b—Br42b^xi	4.14 (2)
Br11—Br21a	4.05 (3)	Br32a—Br32aⁱ	4.066
Br11—Br21b	3.51 (4)	Br32a—Br32aⁱⁱ	4.066
Br11—Br32a^ix	4.08 (3)	Br32a—Br32bⁱ	4.107 (5)
Br11—Br32a^x	4.08 (3)	Br32a—Br32bⁱⁱ	4.107 (5)
Br11—Br32b^ix	3.59 (2)	Br32a—Br42a	4.017 (19)
Br11—Br32b^x	3.59 (2)	Br32a—Br42aⁱⁱ	4.017 (19)
Bi41a—Bi41aⁱ	4.066	Br32a—Br42a^xii	4.017 (19)
Bi41a—Bi41aⁱⁱ	4.066	Br32a—Br42a^xi	4.017 (19)
Bi41a—Br21a	2.88 (2)	Br32a—Br42b	3.57 (2)
Bi41a—Br21aⁱⁱ	2.88 (2)	Br32a—Br42bⁱⁱ	3.57 (2)
Bi41a—Br21b	3.28 (3)	Br32a—Br42b^xii	3.57 (2)
Bi41a—Br21bⁱⁱ	3.28 (3)	Br32a—Br42b^xi	3.57 (2)
Bi41a—Br31a	2.926 (18)	Br32b—Br32bⁱ	4.066
Bi41a—Br31aⁱⁱ	2.926 (18)	Br32b—Br32bⁱⁱ	4.066
Bi41a—Br31b	3.76 (2)	Br32b—Br42b	3.944 (19)
Bi41a—Br31bⁱⁱ	3.76 (2)	Br32b—Br42bⁱⁱ	3.944 (19)
Bi41a—Br41a	2.922 (13)	Br32b—Br42b^xii	3.944 (19)
Bi41a—Br41a^xi	2.922 (13)	Br32b—Br42b^xi	3.944 (19)
Bi41b—Bi41bⁱ	4.066	Br42a—Br42aⁱ	4.066
Bi41b—Bi41bⁱⁱ	4.066	Br42a—Br42aⁱⁱ	4.066
Bi41b—Br21b	2.67 (4)	Br42a—Br42bⁱ	4.138 (3)
Bi41b—Br31b	3.07 (3)	Br42a—Br42bⁱⁱ	4.138 (3)
Bi41b—Br41aⁱ	3.559 (10)	Br42b—Br42bⁱ	4.066
Bi41b—Br41a	3.559 (10)	Br42b—Br42bⁱⁱ	4.066
Bi41b—Br41a^xii	3.559 (10)	Br42b—Br42b^xii	4.005 (14)
Bi41b—Br41a^xi	3.559 (10)

Selected bond lengths (Å) for (Bi7Ni2Br5simplified) top

Bi1—Bi2	3.4086 (12)	Br1—Br2a	3.980 (10)
Bi1—Bi2ⁱ	3.5965 (13)	Br1—Br2aⁱⁱⁱ	3.980 (10)
Bi1—Bi2ⁱⁱ	3.5965 (13)	Br1—Br2b	3.29 (2)
Bi1—Bi3	3.3128 (12)	Br1—Br2bⁱⁱⁱ	3.29 (2)
Bi1—Bi3ⁱⁱⁱ	3.3128 (12)	Br1—Br3a^viii	3.897 (12)
Bi1—Ni	2.737 (2)	Br1—Br3b^viii	3.08 (3)
Bi1—Niⁱⁱⁱ	2.737 (2)	Bi4a—Br2a	2.971 (8)
Bi1—Niⁱ	2.814 (3)	Bi4a—Br2aⁱⁱⁱ	2.971 (8)
Bi1—Br1	3.267 (4)	Bi4a—Br2b	3.63 (2)
Bi1—Br2a	3.830 (4)	Bi4a—Br2bⁱⁱⁱ	3.63 (2)
Bi1—Br2aⁱⁱⁱ	3.830 (4)	Bi4a—Br3a	2.971 (7)
Bi1—Br2b	3.541 (7)	Bi4a—Br3aⁱⁱⁱ	2.971 (7)
Bi1—Br2bⁱⁱⁱ	3.541 (7)	Bi4a—Br3b	3.61 (2)
Bi1—Br4a	3.839 (8)	Bi4a—Br3bⁱⁱⁱ	3.61 (2)
Bi1—Br4b	3.946 (8)	Bi4a—Br4a	2.826 (7)
Bi2—Bi3	3.2477 (13)	Bi4a—Br4a^ix	2.826 (7)
Bi2—Bi3ⁱⁱⁱ	3.2477 (13)	Bi4b—Br2b	3.02 (3)
Bi2—Ni	2.7749 (19)	Bi4b—Br3b	2.97 (3)
Bi2—Niⁱⁱⁱ	2.7749 (19)	Bi4b—Br4a^vi	3.481 (5)
Bi2—Niⁱ	2.785 (3)	Bi4b—Br4a	3.481 (5)
Bi2—Br1ⁱ	3.378 (3)	Bi4b—Br4a^x	3.481 (5)
Bi2—Br1ⁱⁱ	3.378 (3)	Bi4b—Br4a^ix	3.481 (5)
Bi2—Br3b^iv	3.663 (14)	Bi4b—Br4b^vi	2.923 (5)
Bi2—Br3b^v	3.663 (14)	Bi4b—Br4b	2.923 (5)
Bi3—Ni	2.676 (4)	Bi4b—Br4b^x	2.923 (5)
Bi3—Br3a^iv	3.8525 (18)	Bi4b—Br4b^ix	2.923 (5)
Bi3—Br3b^iv	3.818 (2)	Br2a—Br4b^vi	3.657 (8)
Bi3—Br4a^vi	3.523 (6)	Br2a—Br4b	3.657 (8)
Bi3—Br4a	3.523 (6)	Br2a—Br4b^x	3.657 (8)
Bi3—Br4a^iv	3.565 (6)	Br2a—Br4b^ix	3.657 (8)
Bi3—Br4a^v	3.565 (6)	Br3a—Br4b^vi	3.620 (8)
Bi3—Br4b^vi	3.994 (6)	Br3a—Br4b	3.620 (8)
Bi3—Br4b	3.994 (6)	Br3a—Br4b^x	3.620 (8)
Bi3—Br4b^iv	3.794 (6)	Br3a—Br4b^ix	3.620 (8)
Bi3—Br4b^v	3.794 (6)	Br4a—Br4a^v	2.979 (9)
Ni—Ni^vii	2.513 (3)	Br4a—Br4b^v	3.684 (9)
Ni—Niⁱ	2.513 (3)

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