α-SrZn5-Type solid solution, BaZn2.6Cu2.4

Simura, R.; Yamane, H.

doi:10.1107/S2056989019012532

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 75| Part 10| October 2019| Pages 1490-1493

https://doi.org/10.1107/S2056989019012532

Open

access

α-SrZn₅-Type solid solution, BaZn_2.6Cu_2.4

Rayko Simura ^a ^* and Hisanori Yamane ^a

^aInstitute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, 980-8577, Japan
^*Correspondence e-mail: ray@tohoku.ac.jp

Edited by A. Van der Lee, Université de Montpellier II, France (Received 29 August 2019; accepted 9 September 2019; online 20 September 2019)

Single crystals of the title compound barium zinc copper, BaCu_2.6Zn_2.4, were obtained from a sample prepared by heating metal chips of Ba, Cu, and Zn in an Ar atmosphere up to 973 K, followed by slow cooling. Single-crystal X-ray structure analysis revealed that BaCu_2.6Zn_2.4 crystallizes in an orthorhombic cell [a = 12.9858 (3), b = 5.2162 (1), and c = 6.6804 (2) Å] with an α-SrZn₅-type structure (space group Pnma). The three-dimensional framework consists of Cu and Zn atoms, with Ba atoms in the tunnels extending in the b-axis direction. Although the Ba atom is larger than the Sr atom, the cell volume of BaCu_2.6Zn_2.4 [452.507 (19) Å³] is smaller than that of α-SrZn₅ [466.08 Å³]. This decrease in volume can be attributed to the partial substitution of Cu atoms by Zn atoms in the framework because the Cu—Zn and Cu—Cu bonds are shorter than the Zn—Zn bond. The increase in Ba—Zn interatomic distances from the Sr—Zn distances is cancelled out by the partial replacement of Zn with Cu atoms, which leads to shorter average Ba—Zn/Cu distances.

Keywords: crystal structure; barium zinc copper.

CCDC reference: 1952238

1. Chemical context

In A–M binary systems (A = Ca, Sr, Ba, M = Zn, Cu), several phases are present such as AM, AM₅, AM₁₁, and AM₁₃. AM₅ phases appear except for A = Ba with M = Cu. CaZn₅ (Häucke, 1940 ), CaCu₅ (Häucke, 1940), β-SrZn₅ (Bruzzone & Merlo, 1983 ), and SrCu₅ (Bruzzone, 1966 , 1971 ) crystallize in the hexagonal space group P6/mmm, and were reported to have the Kagome structure consisting of Zn or Cu atoms (Wendorff & Röhr, 2007 ). In addition to the high-temperature β-SrZn₅ phase, there exists a low-temperature polymorph of α-SrZn₅ in the orthorhombic space group Pnma (Baenziger & Conant, 1956 ; Bruzzone & Merlo, 1983; Wendorff & Röhr, 2007). BaZn₅ is in the tetragonal space group Cmcm with a structure distorted from P6/mmm-type AM₅ (Baenziger and Conant, 1956). In the present study, single crystals of a new ternary compound BaCu_2.6Zn_2.4 were synthesized, and the crystal structure was analyzed by X-ray diffraction.

2. Structural commentary

The volume for the chemical formula unit of the title compound (113.12 Å³ per formula) calculated from the cell volume V = 452.507 (19) Å³ and Z = 4 is smaller than that of BaZn₅ (120.43 Å³ per formula). The asymmetric unit contains one Ba site (Ba1), one Cu site (Cu1), and three mixed sites of Zn and Cu (Zn/Cu2, Zn/Cu3, Zn/Cu4). As shown in Fig. 1, the Cu1 site is located inside the triangular prism composed of Zn/Cu2, Zn/Cu4, and four Zn/Cu3 sites. The refined occupancy for the Zn/Cu2 site is 0.735 (8)/0.265 (8), while the occupancies of Zn/Cu3 and Zn/Cu4 are almost equivalent at 0.555 (8)/0.445 (8) and 0.555 (4)/0.445 (4), respectively (Table 1). As shown in Table 2, the Cu1—Zn/Cu2 and Cu1—Zn/Cu4 bond lengths are 2.5958 (5) and 2.5840 (6) Å, respectively; Cu1—Zn/Cu3 bond lengths are 2.5664 (4) Å × 2 and 2.6001 (4) Å × 2. The average Cu—Zn/Cu distance is 2.5855 Å, which is shorter than the Zn1—Zn2, Zn1—Zn3, and Zn1—Zn4 distances in α-SrZn₅ (2.6120 Å; Wendorff & Röhr 2007). The Zn/Cu2—Zn/Cu3 bond lengths are 2.5440 (4) Å × 2 and 2.5879 (4) Å × 2; Zn/Cu4—Zn/Cu3 bond lengths are 2.5576 (4) Å × 2 and 2.5756 (4) Å × 2; Zn/Cu3—Zn/Cu3 bond lengths are 2.6075 (5) and 2.6078 (5) Å; and the Zn/Cu4—Zn/Cu4 bond length is 2.8652 (3) Å × 2. These bonds are also shorter than those of SrZn₅ [2.5622 (11) Å × 2 and 2.7260 (11) Å × 2; 2.5594 (11) Å × 2 and 2.6665 (11) Å × 2; 2.6452 (10) and 2.6539 (10) Å; 3.0018 (8) Å × 2], respectively. These shorter Cu—Zn/Cu bonds in BaCu_2.6Zn_2.4 are consistent with the Cu—Cu bond lengths in BaCu₁₃ (2.49–2.68 Å, calculated using the data from Wendorff & Röhr, 2006 ), which are shorter than the Zn—Zn lengths for BaZn₁₃ (2.60–2.94 Å, Bruzzone et al. 1985 ). The average Zn_/Cu—Zn/Cu lengths for Ca(Zn_1-xCu_x)₅ (x = 0.97–0.6) decrease with increasing x (Merlo & Fornasini, 1985 ). In the title compound, the Cu1-centered triangular prisms align in the b- and c-axis directions by sharing the atoms of the Zn/Cu3 site, and form the framework of Cu and Zn atoms shown in Fig. 2.

Table 1
Fractional atomic coordinates and equivalent isotropic displacement parameters for BaCu_2.6Zn_2.4

Atom	x	y	z	U_eq	Occupancy
Ba1	0.41339 (2)	1/4	0.87119 (3)	0.01724 (6)	1
Cu1	0.21263 (3)	1/4	0.17198 (6)	0.01346 (8)	1
Zn/Cu2	0.21485 (3)	1/4	0.56053 (6)	0.01585 (9)	0.555 (8)/0.445 (8)
Zn/Cu3	0.35265 (2)	−0.00006 (5)	0.36005 (4)	0.01279 (7)	0.555 (4)/0.445 (4)
Zn/Cu4	0.01929 (3)	1/4	0.08049 (6)	0.01551 (9)	0.735 (8)/0.265 (8)

Table 2
Selected geometric parameters (Å) for BaCu_2.6Zn_2.4

Ba1—Cu1ⁱ	3.2916 (5)	Cu1—Zn/Cu3^ix	2.5664 (4)
Ba1—Zn/Cu2	3.3097 (5)	Cu1—Zn/Cu3	2.5664 (4)
Ba1—Zn/Cu4ⁱⁱ	3.3160 (5)	Cu1—Zn/Cu4	2.5840 (6)
Ba1—Zn/Cu2ⁱⁱⁱ	3.3429 (3)	Cu1—Zn/Cu2	2.5958 (5)
Ba1—Zn/Cu2^iv	3.3429 (3)	Cu1—Zn/Cu3^xii	2.6001 (4)
Ba1—Cu1ⁱⁱⁱ	3.3542 (3)	Cu1—Zn/Cu3^xiii	2.6001 (4)
Ba1—Cu1^iv	3.3542 (3)	Zn/Cu2—Zn/Cu3^viii	2.5440 (4)
Ba1—Zn/Cu4ⁱⁱⁱ	3.3672 (3)	Zn/Cu2—Zn/Cu3ⁱⁱⁱ	2.5440 (4)
Ba1—Zn/Cu4^iv	3.3672 (3)	Zn/Cu2—Zn/Cu3	2.5879 (4)
Ba1—Zn/Cu3^v	3.6040 (3)	Zn/Cu2—Zn/Cu3^ix	2.5879 (4)
Ba1—Zn/Cu3ⁱ	3.6040 (3)	Zn/Cu3—Zn/Cu3^xiv	2.6075 (5)
Ba1—Zn/Cu3^vi	3.6492 (3)	Zn/Cu3—Zn/Cu3^ix	2.6087 (5)
Ba1—Zn/Cu3^vii	3.6492 (3)	Zn/Cu4—Zn/Cu3^xv	2.5576 (4)
Ba1—Zn/Cu3ⁱⁱⁱ	3.6933 (3)	Zn/Cu4—Zn/Cu3^xvi	2.5576 (4)
Ba1—Zn/Cu3^viii	3.6933 (3)	Zn/Cu4—Zn/Cu3^xii	2.5756 (4)
Ba1—Zn/Cu3	3.7394 (3)	Zn/Cu4—Zn/Cu3^xiii	2.5756 (4)
Ba1—Zn/Cu3^ix	3.7394 (3)	Zn/Cu4—Zn/Cu4^xvii	2.8652 (3)
Ba1—Ba1^x	3.8503 (3)	Zn/Cu4—Zn/Cu4^xviii	2.8652 (3)
Ba1—Ba1^xi	3.8502 (3)

Ba1^x—Ba1—Ba1^xi	85.279 (9)
Symmetry codes: (i) x, y, z + 1; (ii) x + $[{1\over 2}]$ , y, −z + $[{1\over 2}]$ ; (iii) −x + $[{1\over 2}]$ , −y, z + $[{1\over 2}]$ ; (iv) −x + $[{1\over 2}]$ , −y + 1, z + $[{1\over 2}]$ ; (v) x, −y + $[{1\over 2}]$ , z + 1; (vi) −x + 1, y + $[{1\over 2}]$ , −z + 1; (vii) −x + 1, −y, −z + 1; (viii) −x + $[{1\over 2}]$ , y + $[{1\over 2}]$ , z + $[{1\over 2}]$ ; (ix) x, −y + $[{1\over 2}]$ , z; (x) −x + 1, −y + 1, −z + 2; (xi) −x + 1, −y, −z + 2; (xii) −x + $[{1\over 2}]$ , −y, z − $[{1\over 2}]$ ; (xiii) −x + $[{1\over 2}]$ , y + $[{1\over 2}]$ , z − $[{1\over 2}]$ ; (xiv) x, −y − $[{1\over 2}]$ , z; (xv) x − $[{1\over 2}]$ , y, −z + $[{1\over 2}]$ ; (xvi) x − $[{1\over 2}]$ , −y + $[{1\over 2}]$ , −z + $[{1\over 2}]$ ; (xvii) −x, −y, −z; (xviii) −x, −y + 1, −z.

Figure 1
Arrangement of Cu1-centered Zn/Cu trigonal prisms and the Ba1 atoms. Symmetry codes: (i) x, y, z; (ii) $[{1\over 2}]$ − x, 1 − y, $[{1\over 2}]$ + z; (iii) $[{1\over 2}]$ − x, 1 − y, − $[{1\over 2}]$ + z; (iv) x, y, −1 + z; (v) 1 − x, $[{1\over 2}]$ + y, 1 − z; (vi) x, 1 + y, −1 + z; (vii) − $[{1\over 2}]$ + x, $[{1\over 2}]$ − y, $[{3\over 2}]$ − z; (viii) $[{1\over 2}]$ − x, −y, − $[{1\over 2}]$ + z; (ix) x, $[{1\over 2}]$ − y, z; (x) x, 1 + y, z; (xi) $[{1\over 2}]$ − x, $[{1\over 2}]$ + y, − $[{1\over 2}]$ + z; (xii) $[{1\over 2}]$ − x, $[{1\over 2}]$ + y, $[{1\over 2}]$ + z; (xiii) x, $[{1\over 2}]$ − y, −1 + z.

Figure 2
Crystal structure of BaCu_2.6Zn_2.4 illustrated with the Cu1-centered Zn/Cu trigonal prisms.

The Ba1 sites are staggered along the array of the triangular prisms in the tunnel extending in the b-axis direction. The interatomic distance of Ba1—Ba1 [3.8503 (3) Å] is shorter than that of Sr1—Sr1 [4.0230 (13) Å] of α-SrZn_5. The Ba1—Ba1—Ba1 angle [85.279 (9)°] is comparable to the Sr1—Sr1—Sr1 angle of α-SrZn₅ [82.39 (3)°]. There are three Cu1 sites, three Zn/Cu2 sites, eight Zn/Cu3 sites, and three Zn/Cu4 sites around the Ba1 site (Table 2). The average distance of interatomic distances between these 17 sites and the Ba1 site (3.495 Å) is shorter than that between 17 Zn sites and the Ba site of BaZn₅ (3.5832 Å), but is the same as that between 17 Sr sites and the Sr site of α-SrZn₅ (3.495 Å).

Comparison between BaCu₁₃ and BaZn₁₃ having an isotypic structure showed that the atomic distance of Ba—Cu (3.42 Å, calculated using the data by Wendorff & Röhr, 2006) is shorter than that of Ba—Zn (3.59 Å, calculated using the data by Bruzzone et al., 1985). This result is consistent with the fact that the average distance between the Ba1 site and Cu or Zn/Cu sites becomes shorter than the average atomic distance of Ba—Zn in BaZn₅. The lattice size of BaCu_2.6Zn_2.4 is expected to be larger than that of α-SrZn₅ because the interatomic distance of Ba—Zn for BaZn₁₃ is longer than that of Sr—Zn for SrZn₁₃, both of which have the same type of structure. However, the cell constants and volume for BaCu_2.6Zn_2.4 are 0.3–2.0% and 3.0–3.9% smaller than those reported for α-SrZn₅ [a = 13.15 (4), b = 5.32 (1), c = 6.72 (2) Å, V = 470.12 Å³ (Baenziger & Conant, 1956); a = 13.147 (7), b = 5.312 (2), c = 6.707 (3) Å, V = 468.4 Å³ (Bruzzone & Merlo, 1983); and a = 13.133 (3), b = 5.2991 (10), c = 6.6972 (13) Å, V = 466.08 Å³ (Wendorff & Röhr, 2007)]. The average interatomic distance between Ba and the framework forming Zn/Cu atoms in the title compound remains the same as the average Sr—Zn distance of α-SrZn₅ by partial substitution of Cu with Zn atoms. Thus, the decrease in cell volume is caused by the introduction of the shorter Cu—Zn and Cu—Cu bonds in the BaCu_2.6Zn_2.4 framework.

3. Synthesis and crystallization

The title compound was prepared from pieces of Ba (Aldrich Chemicals, 99.9%), Cu (Kojundo Chemical Laboratory Co., Ltd., 99.99%), and Zn (Strem Chemicals Inc., 99.99%) metals with molar ratio of Ba:Cu:Zn = 1:1:1. The metals were placed in a BN crucible (Showa Denko Co., Ltd., purity 99.95%, outer diameter 8.5 mm, inner diameter 6.5 mm, depth 18 mm), which was then put inside a stainless-steel tube (SUS 316: outer diameter 12.7 mm, inner diameter 10.7 mm, height 80 mm) and sealed with a stainless-steel cap in an Ar-filled glove box (MBRAUN; O₂ and H₂O < 1 ppm). The tube was heated to 933 K at a rate of 330 Kh⁻¹ for 10 h, then slowly cooled at a rate of 10 Kh⁻¹ to below 573 K. Finally, the sample was cooled to room temperature by shutting off the electric power to the heater of the furnace. The stainless-steel tube was cut in the Ar-filled glove box. The resulting product contained silver metallic single crystals of the title compound with size of several hundred µm. The surface color of the single crystals changed to metallic gold in air, but crystal decomposition did not occur. A thin layer formed by oxidation may have prevented the further oxidation of the sample. Single crystal XRD data collection was carried out in air. Another single crystal grain obtained from the same sample was buried in resin and polished with a SiC polishing sheet to verify the composition of the crystal by electron probe microanalysis (EPMA, JEOL JXA-8200). A Ba:Cu:Zn atomic ratio of 1.01 ± 0.01:2.62 ± 0.10:2.37 ± 0.09 was obtained by measurements at seven points with the total weight percent of 94–98%. From the EPMA measurement, the chemical composition of the single crystal was determined to be BaCu_2.6Zn_2.4.

4. Refinement

Crystal data, data collection, and structural refinement details are summarized in Table 3. The initial structural model was constructed from the α-SrZn₅ model by substituting the Ba1 site with the Sr1 site, and the Zn/Cu mixed sites with the four Zn sites. In the first stage of refinement, the sum of the occupancies for Cu and Zn atoms in each Zn/Cu site was constrained to be 1. After several refinement iterations, the Cu occupancy for the Zn/Cu1 site became 0.98 (6), and then this site was set to be fully occupied by Cu only. The substitutional occupations of the other three Zn/Cu mixed sites were refined under the restriction that the total chemical composition should be Zn:Cu = 0.48:0.52, which was determined by EPMA.

Table 3
Experimental details

Crystal data
Chemical formula	BaCu_2.60Zn_2.40
M_r	459.5
Crystal system, space group	Orthorhombic, Pnma
Temperature (K)	300
a, b, c (Å)	12.9858 (3), 5.2162 (1), 6.6804 (2)
V (Å³)	452.51 (2)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	32.87
Crystal size (mm)	0.10 × 0.07 × 0.06

Data collection
Diffractometer	Bruker D8 QUEST
Absorption correction	Multi-scan (SADABS; Bruker, 1997 )
T_min, T_max	0.49, 0.75
No. of measured, independent and observed [I > 2σ(I)] reflections	9003, 1038, 956
R_int	0.029
(sin θ/λ)_max (Å⁻¹)	0.794

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.017, 0.032, 1.17
No. of reflections	1038
No. of parameters	39
No. of restraints	1
Δρ_max, Δρ_min (e Å⁻³)	0.96, −0.98
Computer programs: APEX3 (Bruker, 2018 ), SAINT (Bruker, 1997), SHELXT2014/5 (Sheldrick, 2015a ), SHELXL2014/7 (Sheldrick, 2015b ), Crystal Maker X (CrystalMaker Software, 2003 ), publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 1952238

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989019012532/vn2152sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989019012532/vn2152Isup2.hkl

checkCIF report

Computing details top

Data collection: APEX3 (Bruker, 2018); cell refinement: APEX3 (Bruker, 2018); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXT2014/5 (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014/7 (Sheldrick, 2015b); molecular graphics: Crystal Maker X (CrystalMaker Software, 2003); software used to prepare material for publication: publCIF (Westrip, 2010).

barium zinc copper top

Crystal data top

BaCu_2.60Zn_2.40	D_x = 6.744 Mg m⁻³
M_r = 459.5	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pnma	Cell parameters from 198 reflections
a = 12.9858 (3) Å	θ = 3.3–27.3°
b = 5.2162 (1) Å	µ = 32.87 mm⁻¹
c = 6.6804 (2) Å	T = 300 K
V = 452.51 (2) Å³	Chip, metallic light silver
Z = 4	0.10 × 0.07 × 0.06 mm
F(000) = 813.6

Data collection top

Bruker D8 QUEST diffractometer	956 reflections with I > 2σ(I)
Detector resolution: 7.3910 pixels mm^-1	R_int = 0.029
ω and σcans	θ_max = 34.4°, θ_min = 3.1°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −20→20
T_min = 0.49, T_max = 0.75	k = −8→7
9003 measured reflections	l = −10→10
1038 independent reflections

Refinement top

Refinement on F²	1 restraint
Least-squares matrix: full	w = 1/[σ²(F_o²) + (0.0069P)² + 0.6738P] where P = (F_o² + 2F_c²)/3
R[F² > 2σ(F²)] = 0.017	(Δ/σ)_max = 0.003
wR(F²) = 0.032	Δρ_max = 0.96 e Å⁻³
S = 1.17	Δρ_min = −0.98 e Å⁻³
1038 reflections	Extinction correction: SHELXL-2014/7 (Sheldrick 2015b, Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
39 parameters	Extinction coefficient: 0.00318 (18)

Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Ba1	0.41339 (2)	0.2500	0.87119 (3)	0.01724 (6)
Cu1	0.21263 (3)	0.2500	0.17198 (6)	0.01346 (8)
Zn2	0.21485 (3)	0.2500	0.56053 (6)	0.01585 (9)	0.555 (8)
Cu2	0.21485 (3)	0.2500	0.56053 (6)	0.01585 (9)	0.445 (8)
Zn3	0.35265 (2)	−0.00006 (5)	0.36005 (4)	0.01279 (7)	0.555 (4)
Cu3	0.35265 (2)	−0.00006 (5)	0.36005 (4)	0.01279 (7)	0.445 (4)
Zn4	0.01929 (3)	0.2500	0.08049 (6)	0.01551 (9)	0.735 (8)
Cu4	0.01929 (3)	0.2500	0.08049 (6)	0.01551 (9)	0.265 (8)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ba1	0.01853 (10)	0.01541 (10)	0.01779 (10)	0.000	0.00248 (7)	0.000
Cu1	0.01259 (17)	0.01619 (19)	0.01161 (16)	0.000	−0.00309 (13)	0.000
Zn2	0.01913 (19)	0.01558 (19)	0.01283 (17)	0.000	0.00354 (14)	0.000
Cu2	0.01913 (19)	0.01558 (19)	0.01283 (17)	0.000	0.00354 (14)	0.000
Zn3	0.01308 (12)	0.01109 (13)	0.01420 (13)	0.00054 (9)	−0.00154 (9)	0.00036 (9)
Cu3	0.01308 (12)	0.01109 (13)	0.01420 (13)	0.00054 (9)	−0.00154 (9)	0.00036 (9)
Zn4	0.01137 (16)	0.01599 (19)	0.01916 (19)	0.000	0.00157 (13)	0.000
Cu4	0.01137 (16)	0.01599 (19)	0.01916 (19)	0.000	0.00157 (13)	0.000

Geometric parameters (Å, º) top

Ba1—Cu1ⁱ	3.2916 (5)	Cu1—Zn3^vii	2.6001 (4)
Ba1—Zn2	3.3097 (5)	Cu1—Zn3^viii	2.6001 (4)
Ba1—Zn4ⁱⁱ	3.3160 (5)	Cu1—Zn2^ix	2.8711 (2)
Ba1—Zn2ⁱⁱⁱ	3.3429 (3)	Cu1—Zn2^vii	2.8711 (3)
Ba1—Zn2^iv	3.3429 (3)	Zn2—Zn3^x	2.5440 (4)
Ba1—Cu1ⁱⁱⁱ	3.3542 (3)	Zn2—Zn3ⁱⁱⁱ	2.5440 (4)
Ba1—Cu1^iv	3.3542 (3)	Zn2—Zn3	2.5879 (4)
Ba1—Zn4ⁱⁱⁱ	3.3672 (3)	Zn2—Zn3^vi	2.5879 (4)
Ba1—Zn4^iv	3.3672 (3)	Zn3—Zn4ⁱⁱ	2.5576 (4)
Ba1—Zn3^v	3.6040 (3)	Zn3—Zn4ⁱⁱⁱ	2.5756 (4)
Ba1—Zn3ⁱ	3.6040 (3)	Zn3—Zn3^xi	2.6075 (5)
Cu1—Zn3^vi	2.5664 (4)	Zn3—Zn3^vi	2.6087 (5)
Cu1—Zn3	2.5664 (4)	Zn4—Zn4^xii	2.8652 (3)
Cu1—Zn4	2.5840 (6)	Zn4—Zn4^xiii	2.8652 (3)
Cu1—Zn2	2.5958 (5)

Cu1ⁱ—Ba1—Zn2	76.456 (11)	Zn3ⁱⁱⁱ—Zn2—Ba1^ix	121.722 (15)
Cu1ⁱ—Ba1—Zn4ⁱⁱ	152.125 (12)	Zn3—Zn2—Ba1^ix	122.810 (14)
Zn2—Ba1—Zn4ⁱⁱ	75.669 (11)	Zn3^vi—Zn2—Ba1^ix	75.843 (9)
Cu1ⁱ—Ba1—Zn2ⁱⁱⁱ	51.279 (6)	Cu1—Zn2—Ba1^ix	67.425 (9)
Zn2—Ba1—Zn2ⁱⁱⁱ	81.327 (5)	Cu1^iv—Zn2—Ba1^ix	63.436 (8)
Zn4ⁱⁱ—Ba1—Zn2ⁱⁱⁱ	123.428 (7)	Cu1ⁱⁱⁱ—Zn2—Ba1^ix	165.984 (15)
Cu1ⁱ—Ba1—Zn2^iv	51.279 (6)	Ba1—Zn2—Ba1^ix	128.704 (6)
Zn2—Ba1—Zn2^iv	81.327 (5)	Ba1^vii—Zn2—Ba1^ix	102.556 (13)
Zn4ⁱⁱ—Ba1—Zn2^iv	123.428 (7)	Zn3^x—Zn2—Ba1^xv	64.323 (11)
Zn2ⁱⁱⁱ—Ba1—Zn2^iv	102.555 (13)	Zn3ⁱⁱⁱ—Zn2—Ba1^xv	64.323 (11)
Cu1ⁱ—Ba1—Cu1ⁱⁱⁱ	81.710 (5)	Zn3—Zn2—Ba1^xv	138.309 (12)
Zn2—Ba1—Cu1ⁱⁱⁱ	51.038 (6)	Zn3^vi—Zn2—Ba1^xv	138.309 (12)
Zn4ⁱⁱ—Ba1—Cu1ⁱⁱⁱ	80.868 (9)	Cu1—Zn2—Ba1^xv	96.009 (15)
Zn2ⁱⁱⁱ—Ba1—Cu1ⁱⁱⁱ	45.610 (9)	Cu1^iv—Zn2—Ba1^xv	107.206 (11)
Zn2^iv—Ba1—Cu1ⁱⁱⁱ	120.913 (11)	Cu1ⁱⁱⁱ—Zn2—Ba1^xv	107.206 (11)
Cu1ⁱ—Ba1—Cu1^iv	81.710 (5)	Ba1—Zn2—Ba1^xv	134.520 (11)
Zn2—Ba1—Cu1^iv	51.038 (6)	Ba1^vii—Zn2—Ba1^xv	63.193 (8)
Zn4ⁱⁱ—Ba1—Cu1^iv	80.868 (9)	Ba1^ix—Zn2—Ba1^xv	63.193 (8)
Zn2ⁱⁱⁱ—Ba1—Cu1^iv	120.913 (11)	Zn2^vii—Zn3—Zn4ⁱⁱ	132.457 (17)
Zn2^iv—Ba1—Cu1^iv	45.610 (9)	Zn2^vii—Zn3—Cu1	68.362 (11)
Cu1ⁱⁱⁱ—Ba1—Cu1^iv	102.074 (12)	Zn4ⁱⁱ—Zn3—Cu1	114.601 (13)
Cu1ⁱ—Ba1—Zn4ⁱⁱⁱ	123.899 (7)	Zn2^vii—Zn3—Zn4ⁱⁱⁱ	114.379 (13)
Zn2—Ba1—Zn4ⁱⁱⁱ	80.829 (9)	Zn4ⁱⁱ—Zn3—Zn4ⁱⁱⁱ	67.858 (9)
Zn4ⁱⁱ—Ba1—Zn4ⁱⁱⁱ	50.766 (6)	Cu1—Zn3—Zn4ⁱⁱⁱ	174.066 (17)
Zn2ⁱⁱⁱ—Ba1—Zn4ⁱⁱⁱ	75.123 (8)	Zn2^vii—Zn3—Zn2	115.282 (11)
Zn2^iv—Ba1—Zn4ⁱⁱⁱ	162.151 (12)	Zn4ⁱⁱ—Zn3—Zn2	104.336 (14)
Cu1ⁱⁱⁱ—Ba1—Zn4ⁱⁱⁱ	45.217 (9)	Cu1—Zn3—Zn2	60.479 (14)
Cu1^iv—Ba1—Zn4ⁱⁱⁱ	120.008 (10)	Zn4ⁱⁱⁱ—Zn3—Zn2	113.935 (15)
Cu1ⁱ—Ba1—Zn4^iv	123.899 (7)	Zn2^vii—Zn3—Cu1ⁱⁱⁱ	105.132 (14)
Zn2—Ba1—Zn4^iv	80.829 (9)	Zn4ⁱⁱ—Zn3—Cu1ⁱⁱⁱ	114.021 (16)
Zn4ⁱⁱ—Ba1—Zn4^iv	50.766 (6)	Cu1—Zn3—Cu1ⁱⁱⁱ	114.595 (11)
Zn2ⁱⁱⁱ—Ba1—Zn4^iv	162.151 (12)	Zn4ⁱⁱⁱ—Zn3—Cu1ⁱⁱⁱ	59.898 (13)
Zn2^iv—Ba1—Zn4^iv	75.123 (8)	Zn2—Zn3—Cu1ⁱⁱⁱ	67.204 (10)
Cu1ⁱⁱⁱ—Ba1—Zn4^iv	120.008 (10)	Zn2^vii—Zn3—Zn3^xi	59.170 (7)
Cu1^iv—Ba1—Zn4^iv	45.217 (9)	Zn4ⁱⁱ—Zn3—Zn3^xi	120.663 (8)
Zn4ⁱⁱⁱ—Ba1—Zn4^iv	101.532 (12)	Cu1—Zn3—Zn3^xi	120.547 (7)
Cu1ⁱ—Ba1—Zn3^v	43.406 (7)	Zn4ⁱⁱⁱ—Zn3—Zn3^xi	59.590 (7)
Zn2—Ba1—Zn3^v	113.437 (9)	Zn2—Zn3—Zn3^xi	120.266 (7)
Zn4ⁱⁱ—Ba1—Zn3^v	156.251 (6)	Cu1ⁱⁱⁱ—Zn3—Zn3^xi	59.906 (7)
Zn2ⁱⁱⁱ—Ba1—Zn3^v	80.241 (8)	Zn2^vii—Zn3—Zn3^vi	120.829 (7)
Zn2^iv—Ba1—Zn3^v	42.758 (8)	Zn4ⁱⁱ—Zn3—Zn3^vi	59.337 (8)
Cu1ⁱⁱⁱ—Ba1—Zn3^v	122.288 (9)	Cu1—Zn3—Zn3^vi	59.453 (7)
Cu1^iv—Ba1—Zn3^v	88.359 (8)	Zn4ⁱⁱⁱ—Zn3—Zn3^vi	120.410 (7)
Zn4ⁱⁱⁱ—Ba1—Zn3^v	149.290 (8)	Zn2—Zn3—Zn3^vi	59.734 (7)
Zn4^iv—Ba1—Zn3^v	107.404 (7)	Cu1ⁱⁱⁱ—Zn3—Zn3^vi	120.095 (7)
Cu1ⁱ—Ba1—Zn3ⁱ	43.406 (7)	Zn3^xi—Zn3—Zn3^vi	180.0
Zn2—Ba1—Zn3ⁱ	113.437 (10)	Zn2^vii—Zn3—Ba1^xiv	63.138 (9)
Zn4ⁱⁱ—Ba1—Zn3ⁱ	156.251 (6)	Zn4ⁱⁱ—Zn3—Ba1^xiv	76.764 (11)
Zn2ⁱⁱⁱ—Ba1—Zn3ⁱ	42.758 (8)	Cu1—Zn3—Ba1^xiv	61.802 (11)
Zn2^iv—Ba1—Zn3ⁱ	80.241 (8)	Zn4ⁱⁱⁱ—Zn3—Ba1^xiv	124.057 (13)
Cu1ⁱⁱⁱ—Ba1—Zn3ⁱ	88.359 (8)	Zn2—Zn3—Ba1^xiv	115.967 (11)
Cu1^iv—Ba1—Zn3ⁱ	122.288 (9)	Cu1ⁱⁱⁱ—Zn3—Ba1^xiv	168.248 (12)
Zn4ⁱⁱⁱ—Ba1—Zn3ⁱ	107.404 (7)	Zn3^xi—Zn3—Ba1^xiv	111.218 (4)
Zn4^iv—Ba1—Zn3ⁱ	149.290 (8)	Zn3^vi—Zn3—Ba1^xiv	68.782 (4)
Zn3^v—Ba1—Zn3ⁱ	42.436 (9)	Zn2^vii—Zn3—Ba1^xvi	76.752 (12)
Zn3^vi—Cu1—Zn3	61.093 (15)	Zn4ⁱⁱ—Zn3—Ba1^xvi	62.842 (9)
Zn3^vi—Cu1—Zn4	143.536 (12)	Cu1—Zn3—Ba1^xvi	124.350 (13)
Zn3—Cu1—Zn4	143.535 (12)	Zn4ⁱⁱⁱ—Zn3—Ba1^xvi	61.552 (11)
Zn3^vi—Cu1—Zn2	60.171 (12)	Zn2—Zn3—Ba1^xvi	167.121 (13)
Zn3—Cu1—Zn2	60.171 (12)	Cu1ⁱⁱⁱ—Zn3—Ba1^xvi	115.565 (11)
Zn4—Cu1—Zn2	104.319 (19)	Zn3^xi—Zn3—Ba1^xvi	69.067 (4)
Zn3^vi—Cu1—Zn3^vii	151.424 (19)	Zn3^vi—Zn3—Ba1^xvi	110.932 (4)
Zn3—Cu1—Zn3^vii	111.623 (8)	Ba1^xiv—Zn3—Ba1^xvi	64.121 (6)
Zn4—Cu1—Zn3^vii	59.580 (12)	Zn2^vii—Zn3—Ba1^vii	60.831 (11)
Zn2—Cu1—Zn3^vii	143.610 (13)	Zn4ⁱⁱ—Zn3—Ba1^vii	165.534 (13)
Zn3^vi—Cu1—Zn3^viii	111.623 (8)	Cu1—Zn3—Ba1^vii	61.739 (9)
Zn3—Cu1—Zn3^viii	151.425 (19)	Zn4ⁱⁱⁱ—Zn3—Ba1^vii	114.440 (11)
Zn4—Cu1—Zn3^viii	59.580 (12)	Zn2—Zn3—Ba1^vii	61.359 (9)
Zn2—Cu1—Zn3^viii	143.610 (13)	Cu1ⁱⁱⁱ—Zn3—Ba1^vii	60.125 (11)
Zn3^vii—Cu1—Zn3^viii	60.188 (14)	Zn3^xi—Zn3—Ba1^vii	69.329 (4)
Zn3^vi—Cu1—Zn2^ix	55.449 (11)	Zn3^vi—Zn3—Ba1^vii	110.672 (4)
Zn3—Cu1—Zn2^ix	110.868 (16)	Ba1^xiv—Zn3—Ba1^vii	110.530 (8)
Zn4—Cu1—Zn2^ix	104.914 (12)	Ba1^xvi—Zn3—Ba1^vii	131.391 (8)
Zn2—Cu1—Zn2^ix	104.812 (11)	Zn3^xvii—Zn4—Zn3^xviii	61.325 (15)
Zn3^vii—Cu1—Zn2^ix	110.769 (15)	Zn3^xvii—Zn4—Zn3^viii	153.278 (18)
Zn3^viii—Cu1—Zn2^ix	56.195 (11)	Zn3^xviii—Zn4—Zn3^viii	112.142 (9)
Zn3^vi—Cu1—Zn2^vii	110.868 (16)	Zn3^xvii—Zn4—Zn3^vii	112.142 (9)
Zn3—Cu1—Zn2^vii	55.449 (11)	Zn3^xviii—Zn4—Zn3^vii	153.278 (18)
Zn4—Cu1—Zn2^vii	104.914 (12)	Zn3^viii—Zn4—Zn3^vii	60.821 (15)
Zn2—Cu1—Zn2^vii	104.812 (11)	Zn3^xvii—Zn4—Cu1	141.749 (13)
Zn3^vii—Cu1—Zn2^vii	56.195 (11)	Zn3^xviii—Zn4—Cu1	141.749 (13)
Zn3^viii—Cu1—Zn2^vii	110.769 (15)	Zn3^viii—Zn4—Cu1	60.522 (12)
Zn2^ix—Cu1—Zn2^vii	130.57 (2)	Zn3^vii—Zn4—Cu1	60.522 (12)
Zn3^vi—Cu1—Ba1^xiv	74.792 (12)	Zn3^xvii—Zn4—Zn4^xii	56.370 (13)
Zn3—Cu1—Ba1^xiv	74.792 (12)	Zn3^xviii—Zn4—Zn4^xii	112.00 (2)
Zn4—Cu1—Ba1^xiv	128.695 (16)	Zn3^viii—Zn4—Zn4^xii	111.04 (2)
Zn2—Cu1—Ba1^xiv	126.987 (17)	Zn3^vii—Zn4—Zn4^xii	55.772 (13)
Zn3^vii—Cu1—Ba1^xiv	76.642 (12)	Cu1—Zn4—Zn4^xii	104.989 (16)
Zn3^viii—Cu1—Ba1^xiv	76.642 (12)	Zn3^xvii—Zn4—Zn4^xiii	112.00 (2)
Zn2^ix—Cu1—Ba1^xiv	65.285 (11)	Zn3^xviii—Zn4—Zn4^xiii	56.370 (13)
Zn2^vii—Cu1—Ba1^xiv	65.285 (11)	Zn3^viii—Zn4—Zn4^xiii	55.772 (13)
Zn3^x—Zn2—Zn3ⁱⁱⁱ	61.660 (15)	Zn3^vii—Zn4—Zn4^xiii	111.04 (2)
Zn3^x—Zn2—Zn3	154.64 (2)	Cu1—Zn4—Zn4^xiii	104.989 (16)
Zn3ⁱⁱⁱ—Zn2—Zn3	112.768 (8)	Zn4^xii—Zn4—Zn4^xiii	131.08 (3)
Zn3^x—Zn2—Zn3^vi	112.768 (8)	Zn3^xvii—Zn4—Ba1^xvii	77.904 (12)
Zn3ⁱⁱⁱ—Zn2—Zn3^vi	154.64 (2)	Zn3^xviii—Zn4—Ba1^xvii	77.904 (12)
Zn3—Zn2—Zn3^vi	60.531 (15)	Zn3^viii—Zn4—Ba1^xvii	75.374 (12)
Zn3^x—Zn2—Cu1	141.503 (14)	Zn3^vii—Zn4—Ba1^xvii	75.374 (12)
Zn3ⁱⁱⁱ—Zn2—Cu1	141.503 (14)	Cu1—Zn4—Ba1^xvii	128.184 (17)
Zn3—Zn2—Cu1	59.350 (12)	Zn4^xii—Zn4—Ba1^xvii	65.542 (15)
Zn3^vi—Zn2—Cu1	59.350 (12)	Zn4^xiii—Zn4—Ba1^xvii	65.542 (15)
Zn3^x—Zn2—Cu1^iv	56.189 (10)	Zn3^xvii—Zn4—Ba1^ix	121.676 (15)
Zn3ⁱⁱⁱ—Zn2—Cu1^iv	112.000 (16)	Zn3^xviii—Zn4—Ba1^ix	74.638 (9)
Zn3—Zn2—Cu1^iv	111.420 (16)	Zn3^viii—Zn4—Ba1^ix	76.705 (9)
Zn3^vi—Zn2—Cu1^iv	56.601 (10)	Zn3^vii—Zn4—Ba1^ix	123.655 (15)
Cu1—Zn2—Cu1^iv	105.245 (11)	Cu1—Zn4—Ba1^ix	67.126 (9)
Zn3^x—Zn2—Cu1ⁱⁱⁱ	112.000 (16)	Zn4^xii—Zn4—Ba1^ix	165.22 (2)
Zn3ⁱⁱⁱ—Zn2—Cu1ⁱⁱⁱ	56.189 (10)	Zn4^xiii—Zn4—Ba1^ix	63.692 (10)
Zn3—Zn2—Cu1ⁱⁱⁱ	56.601 (10)	Ba1^xvii—Zn4—Ba1^ix	129.234 (6)
Zn3^vi—Zn2—Cu1ⁱⁱⁱ	111.420 (16)	Zn3^xvii—Zn4—Ba1^vii	74.638 (9)
Cu1—Zn2—Cu1ⁱⁱⁱ	105.245 (11)	Zn3^xviii—Zn4—Ba1^vii	121.676 (15)
Cu1^iv—Zn2—Cu1ⁱⁱⁱ	130.57 (2)	Zn3^viii—Zn4—Ba1^vii	123.655 (15)
Zn3^x—Zn2—Ba1	77.010 (12)	Zn3^vii—Zn4—Ba1^vii	76.705 (9)
Zn3ⁱⁱⁱ—Zn2—Ba1	77.010 (12)	Cu1—Zn4—Ba1^vii	67.126 (9)
Zn3—Zn2—Ba1	77.635 (12)	Zn4^xii—Zn4—Ba1^vii	63.692 (10)
Zn3^vi—Zn2—Ba1	77.635 (12)	Zn4^xiii—Zn4—Ba1^vii	165.22 (2)
Cu1—Zn2—Ba1	129.470 (17)	Ba1^xvii—Zn4—Ba1^vii	129.234 (6)
Cu1^iv—Zn2—Ba1	65.284 (11)	Ba1^ix—Zn4—Ba1^vii	101.532 (12)
Cu1ⁱⁱⁱ—Zn2—Ba1	65.284 (11)	Zn3^xvii—Zn4—Ba1^xv	63.718 (10)
Zn3^x—Zn2—Ba1^vii	121.722 (15)	Zn3^xviii—Zn4—Ba1^xv	63.718 (11)
Zn3ⁱⁱⁱ—Zn2—Ba1^vii	74.105 (9)	Zn3^viii—Zn4—Ba1^xv	139.660 (11)
Zn3—Zn2—Ba1^vii	75.842 (9)	Zn3^vii—Zn4—Ba1^xv	139.660 (11)
Zn3^vi—Zn2—Ba1^vii	122.810 (14)	Cu1—Zn4—Ba1^xv	96.897 (15)
Cu1—Zn2—Ba1^vii	67.425 (9)	Zn4^xii—Zn4—Ba1^xv	106.854 (15)
Cu1^iv—Zn2—Ba1^vii	165.984 (15)	Zn4^xiii—Zn4—Ba1^xv	106.854 (15)
Cu1ⁱⁱⁱ—Zn2—Ba1^vii	63.436 (8)	Ba1^xvii—Zn4—Ba1^xv	134.919 (13)
Ba1—Zn2—Ba1^vii	128.704 (6)	Ba1^ix—Zn4—Ba1^xv	63.342 (8)
Zn3^x—Zn2—Ba1^ix	74.105 (9)	Ba1^vii—Zn4—Ba1^xv	63.342 (8)

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

Fractional atomic coordinates and equivalent isotropic displacement parameters for BaCu_2.6Zn_2.4 top

Atom	x	y	z	U_eq	Occupancy
Ba1	0.41339 (2)	1/4	0.87119 (3)	0.01724 (6)	1
Cu1	0.21263 (3)	1/4	0.17198 (6)	0.01346 (8)	1
Zn/Cu2	0.21485 (3)	1/4	0.56053 (6)	0.01585 (9)	0.555 (8)/0.445 (8)
Zn/Cu3	0.35265 (2)	-0.00006 (5)	0.36005 (4)	0.01279 (7)	0.555 (4)/0.445 (4)
Zn/Cu4	0.01929 (3)	1/4	0.08049 (6)	0.01551 (9)	0.735 (8)/0.265 (8)

Selected geometric parameters (Å) for BaCu_2.6Zn_2.4 top

Ba1—Cu1ⁱ	3.2916 (5)	Cu1—Zn/Cu3^ix	2.5664 (4)
Ba1—Zn/Cu2	3.3097 (5)	Cu1—Zn/Cu3	2.5664 (4)
Ba1—Zn/Cu4ⁱⁱ	3.3160 (5)	Cu1—Zn/Cu4	2.5840 (6)
Ba1—Zn/Cu2ⁱⁱⁱ	3.3429 (3)	Cu1—Zn/Cu2	2.5958 (5)
Ba1—Zn/Cu2^iv	3.3429 (3)	Cu1—Zn/Cu3^xii	2.6001 (4)
Ba1—Cu1ⁱⁱⁱ	3.3542 (3)	Cu1—Zn/Cu3^xiii	2.6001 (4)
Ba1—Cu1^iv	3.3542 (3)	Zn/Cu2—Zn/Cu3^viii	2.5440 (4)
Ba1—Zn/Cu4ⁱⁱⁱ	3.3672 (3)	Zn/Cu2—Zn/Cu3ⁱⁱⁱ	2.5440 (4)
Ba1—Zn/Cu4^iv	3.3672 (3)	Zn/Cu2—Zn/Cu3	2.5879 (4)
Ba1—Zn/Cu3^v	3.6040 (3)	Zn/Cu2—Zn/Cu3^ix	2.5879 (4)
Ba1—Zn/Cu3ⁱ	3.6040 (3)	Zn/Cu3—Zn/Cu3^xiv	2.6075 (5)
Ba1—Zn/Cu3^vi	3.6492 (3)	Zn/Cu3—Zn/Cu3^ix	2.6087 (5)
Ba1—Zn/Cu3^vii	3.6492 (3)	Zn/Cu4—Zn/Cu3^xv	2.5576 (4)
Ba1—Zn/Cu3ⁱⁱⁱ	3.6933 (3)	Zn/Cu4—Zn/Cu3^xvi	2.5576 (4)
Ba1—Zn/Cu3^viii	3.6933 (3)	Zn/Cu4—Zn/Cu3^xii	2.5756 (4)
Ba1—Zn/Cu3	3.7394 (3)	Zn/Cu4—Zn/Cu3^xiii	2.5756 (4)
Ba1—Zn/Cu3^ix	3.7394 (3)	Zn/Cu4—Zn/Cu4^xvii	2.8652 (3)
Ba1—Ba1^x	3.8503 (3)	Zn/Cu4—Zn/Cu4^xviii	2.8652 (3)
Ba1—Ba1^xi	3.8502 (3)

Ba1^x—Ba1—Ba1^xi	85.279 (9)

Symmetry codes: (i) x, y, z + 1; (ii) x + 1/2, y, -z + 1/2; (iii) -x + 1/2, -y, z + 1/2; (iv) -x + 1/2, -y + 1, z + 1/2; (v) x, -y + 1/2, z + 1; (vi) -x + 1, y + 1/2, -z + 1; (vii) -x + 1, -y, -z + 1; (viii) -x + 1/2, y + 1/2, z + 1/2; (ix) x, -y + 1/2, z; (x) -x + 1, -y + 1, -z + 2; (xi) -x + 1, -y, -z + 2; (xii) -x + 1/2, -y, z - 1/2; (xiii) -x + 1/2, y + 1/2, z - 1/2; (xiv) x, -y - 1/2, z; (xv) x - 1/2, y, -z + 1/2; (xvi) x - 1/2, -y + 1/2, -z + 1/2; (xvii) -x, -y, -z; (xviii) -x, -y + 1, -z.

Acknowledgements

The authors wish to thank Mr T. Kamaya at the Central Analytical Facility (CAF), Institute of Multidisciplinary Research for Advanced Materials (IMRAM), Tohoku University for performing the EPMA analysis.

Funding information

Funding for this research was provided by: Japan Society for the Promotion of Science (grant No. JP18H05347).

References

Baenziger, N. C. & Conant, J. W. (1956). Acta Cryst. 9, 361–364. CrossRef ICSD CAS IUCr Journals Web of Science Google Scholar
Bruker (1997). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruker (2018). APEX3. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Bruzzone, G. (1966). Atti Accad. Naz. Lincei. Rend. Cl. Sci. Fs. Mat. Nat. 41, 90–96. CAS Google Scholar
Bruzzone, G. (1971). J. Less-Common Met. 25, 361–366. CrossRef ICSD CAS Google Scholar
Bruzzone, G., Ferretti, M. & Merlo, F. (1985). J. Less-Common Met. 114, 305–310. CrossRef ICSD CAS Web of Science Google Scholar
Bruzzone, G. & Merlo, F. (1983). J. Less-Common Met. 92, 75–79. CrossRef ICSD CAS Google Scholar
CrystalMaker Software (2003). CrystalMaker. CrystalMaker Software, Bicester, England. Google Scholar
Häucke, W. (1940). Z. Anorg. Allg. Chem. 244, 17–22. Google Scholar
Merlo, F. & Fornasini, M. L. (1985). J. Less-Common Met. 109, 135–146. CrossRef ICSD CAS Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Wendorff, M. & Röhr, C. (2006). J. Alloys Compd. 421, 24–34. CrossRef ICSD CAS Google Scholar
Wendorff, M. & Röhr, C. (2007). Z. Naturforsch. B, 62, 1549–1562. CrossRef CAS Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar