Ba₃Y₂B₆O₁₅, a novel cubic borate

Single crystals of tribarium diyttrium hexa­borate, which crystallized in the cubic system, have been obtained by spontaneous crystallization from a high-temperature melt using Li₂O-BaO-B₂O₃ as flux. Its structure is composed of isolated [B₂O₅]^4- groups, irregular BaO₉ polyhedra and regular YO₆ polyhedra which occupy alternate sites running along the [111] direction. Irregular BaO₉ polyhedra and regular YO₆ polyhedra construct a three-dimensional framework, which is reinforced by [B₂O₅]^4- groups.

S1. Comment

Rare-earth borates have attracted considerable attention in the past few decades owing to their practical applications as nonlinear optical (NLO) materials (Mills, 1962; Norrestam et al., 1992; Wu et al., 2001; Gravereau et al., 2002) and plasma display panel (PDP) phosphors (Chadeyron et al., 1997). To date, five ternary compounds, BaYB₉O₁₆ (Fu et al., 1987), Ba₃YB₉O₁₈ (Li, Wang et al., 2004), Ba₃Y(BO₃)₃ (α and β phases) (Pan & Wang, 2003; Li, Chen et al., 2004a), Ba₃Y₂(BO₃)₄ (Ma et al., 2005) and BaY₃B₃O₁₀ (Li, Chen et al., 2004b), have been reported in the BaO–Y₂O₃–B₂O₃ system. Herein we describe the crystal structure of a novel borate, Ba₃Y₂B₆O₁₅. It crystallized in the cubic system, which is very rare in borates [about 1.18% of PDF compounds containing boron and oxygen [crystallize in this system], and [the figure is] even less in borate, according to Wu et al. (2005)].

The fundamental building unit of Ba₃Y₂B₆O₁₅ is an isolated [B₂O₅]^4- group, which is formed by two identical BO₃ triangles sharing the bridging O2 atom. Each [B₂O₅]^4- anionic group connects to six Ba atoms and four Y atoms via O atoms (Fig. 1). The B—O bond lengths range from 1.356 (4) to 1.406 (4) Å and the mean O—B—O bond angles are equal to 120°, which indicates that they are almost planar. These values are normal for the [B₂O₅]^4- group. The Ba atoms are coordinated by nine O atoms in irregular polyhedra with Ba—O bond lengths ranging from 2.732 (3) to 3.018 (3) Å. These values compare well with the value of Ba—O bond lengths of the nine-coordinate Ba²⁺ ion in Ba₃YB₉O₁₈. The Y atoms appear in two crystallographically different environments. Both Y1 and Y2 atoms are octahedrally coordinated by borate O atoms, forming regular YO₆ octahedra running right along the [111] direction alternately (Fig. 2). The YO₆ octahedra are isolated from each other by the intervening BaO₉ polyhedra and pyroborate groups. The Y1—O1 and Y2—O3 bond distances, 2.271 (3) and 2.250 (3) Å, respectively, are consistent with the sum of crystal radii (Brown & Altermatt, 1985). Irregular BaO₉ polyhedra and regular YO₆ polyhedra are interconnected to each other constructing a three-dimensional framework, which is reinforced by [B₂O₅]^4- groups.

The structure of the title compound is closely related to that of Al₄B₆O₁₅, which could be described with pseudo-cubic symmetry. The fundamental building unit of Al₄B₆O₁₅ is the [B₂O₅]^4- group. Within the [B₂O₅]^4- group, the B—O—B angle (119.8°) is almost equal to that of Ba₃Y₂B₆O₁₅ (122.0°), but the interplanar angle (16.9°) between the two terminal BO₂ planes is much smaller than that of Ba₃Y₂B₆O₁₅ (59.0°). According to Thompson et al. (1991), the terminal BO₂ planes pivot about the torsion angles to afford deviations from coplanarity that range from 0 to 76.8°, while the central B—O—B angle ranges from 111.8 to 180°. The O···O repulsive interactions can be relieved by torsional motions which produce nonzero interplanar angles between the two terminal BO₂ planes. Because of the small interplanar angle, the O···O repulsive interactions could not be relieved efficiently, which might be one of the reasons why the compound Al₄B₆O₁₅ is difficult to synthesize. Because of the different bond lengths of Al—O, Y—O and Ba—O, their coordination environments are different. Each AlO₆ octahedron shares three independent edges with adjacent AlO₆ octahedra, while each YO₆ octahedron shares six interconncted edges with adjacent BaO₉ polyhedra. Each BaO₉ polyhedron connects to two BaO₉ polyhedra and two YO6 octahedra by sharing edges, as well as another two BaO₉ polyhedra by sharing vertices.

Bond-valence sums (BVS; Brown & Altermatt, 1985) of the Ba, Y and B atoms were calculated. The BVS values of the Ba, Y1, Y2 and B atoms are 2.0, 3.0, 3.2 and 3.0, respectively. All these values are close to expected values.

Related literature

For related literature, see: Brown & Altermatt (1985); Chadeyron et al. (1997); Fu et al. (1987); Gravereau et al. (2002); Li et al. (2004, 2004a, 2004b); Ma et al. (2005); Mills (1962); Norrestam et al. (1992); Pan & Wang (2003); Thompson et al. (1991); Wu et al. (2001, 2005).

S2. Experimental

Single crystals of Ba₃Y₂B₆O₁₅ were grown from a Li₂O–BaO–B₂O₃ flux system by spontaneous crystallization. Mixtures of analytical purity BaCO₃, Y₂O₃ and H₃BO₃ in stoichiometric proportions were sintered at 773 K for 24 h, and then sintered at 1123 K for 72 h with several intermediate grindings. Prepared Ba₃Y₂B₆O₁₅ polycrystalline samples (54.090 g) and analytical purity Li₂CO₃ (2.220 g), BaCO₃ (23.730 g), H₃BO₃ (18.750 g) were melted in a Ø40×40 mm Pt crucible at 1373 K for 5 h to ensure homogeneity, cooled to 1273 K at a rate of 2 K h^-1, and finally cooled to room temperature at a rate of 50 K h^-1. A clear, colourless crystal was physically separated from the melt for analysis.

S3. Refinement

The structure was solved with the direct methods program SHELXS97 (Sheldrick, 2008) and refined with the least-squares program SHELXL97 of the SHELXTL.PC suite of programs (Sheldrick, 2008). The final refinement included anisotropic displacement parameters and a secondary extinction correction. The program STRUCTURE_TIDY (Ref?) was then employed to standardize the atomic coordinates.

Computing details

Data collection: CrystalClear (Rigaku, 2008); cell refinement: CrystalClear (Rigaku, 2008); data reduction: CrystalClear (Rigaku, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. The coordination environment of the [B2O5]^4- group. Displacement ellipsoids are drawn at the 80% probability level. [Symmetry codes: (i) -z+1/2, x+1/2, y; (ii) z, x+1/2, -y; (iii) -y+1/2, z, -x; (iv) z, x, y; (v) -x+1/2, -y+1/2, -z+1/2; (vi) -y+1/2, z, -x; (vii) x, -y+1/2, z-1/2.]
	Fig. 2. A projection of the structure of Ba3Y2B6O15. BaO9 polyhedra and YO6 polyhedra construct a three-dimensional framework, which is reinforced by [B2O5]^4- groups. Atoms Y1 and Y2 occupy alternate sites running along the [111] direction.

tribarium biyttrium hexaborate

Crystal data

Ba3Y2B6O15	Dx = 4.105 Mg m^−3
Mr = 894.70	Mo Kα radiation, λ = 0.71073 Å
Cubic, Ia3	Cell parameters from 5120 reflections
Hall symbol: -I 2b 2c 3	θ = 2.9–30.0°
a = 14.253 (6) Å	µ = 16.05 mm^−1
V = 2895 (2) Å^3	T = 153 K
Z = 8	Chip, colourless
F(000) = 3168	0.22 × 0.20 × 0.17 mm

Data collection

Rigaku AFC10 diffractometer	712 independent reflections
Radiation source: fine-focus sealed tube	704 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.053
Detector resolution: 28.5714 pixels mm^-1	θmax = 30.0°, θmin = 2.9°
dtprofit.ref scans	h = −20→16
Absorption correction: multi-scan (ABSCOR; Higashi, 1995)	k = −17→18
Tmin = 0.635, Tmax = 1.000	l = −20→20
12264 measured reflections

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.021	w = 1/[σ^2(Fo^2) + (0.020P)^2 + 30.P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.047	(Δ/σ)max = 0.001
S = 1.09	Δρmax = 0.81 e Å^−3
712 reflections	Δρmin = −0.62 e Å^−3
43 parameters	Extinction correction: SHELXL, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.00075 (4)

Special details

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.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Ba1	0.368191 (18)	0.0000	0.2500	0.00240 (11)
Y1	0.0000	0.0000	0.5000	0.00163 (16)
Y2	0.2500	0.2500	0.2500	0.00175 (16)
B1	0.1120 (3)	0.0640 (3)	0.3078 (3)	0.0042 (6)
O1	0.02893 (17)	0.04114 (17)	0.34885 (17)	0.0052 (5)
O2	0.1597 (3)	0.0000	0.2500	0.0075 (7)
O3	0.15544 (17)	0.14718 (16)	0.32350 (17)	0.0052 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ba1	0.00277 (15)	0.00186 (14)	0.00258 (14)	0.000	0.000	0.00051 (8)
Y1	0.00163 (16)	0.00163 (16)	0.00163 (16)	−0.00058 (13)	−0.00058 (13)	0.00058 (13)
Y2	0.00175 (16)	0.00175 (16)	0.00175 (16)	0.00034 (13)	0.00034 (13)	0.00034 (13)
B1	0.0048 (15)	0.0032 (14)	0.0045 (15)	0.0021 (12)	−0.0025 (12)	0.0010 (11)
O1	0.0021 (10)	0.0080 (11)	0.0056 (10)	−0.0016 (8)	0.0005 (8)	0.0010 (8)
O2	0.0017 (15)	0.0092 (17)	0.0117 (17)	0.000	0.000	−0.0066 (13)
O3	0.0044 (10)	0.0041 (10)	0.0069 (11)	−0.0002 (9)	0.0000 (8)	−0.0014 (8)

Geometric parameters (Å, º)

Ba1—O1^i	3.018 (3)	Y1—Ba1^xvii	4.0282 (17)
Ba1—O2	2.971 (4)	Y1—Ba1^xviii	4.0282 (17)
Ba1—O3^ii	2.732 (3)	Y2—O3^xix	2.250 (3)
Ba1—O3^iii	2.862 (3)	Y2—O3	2.250 (3)
Ba1—O3^i	2.732 (3)	Y2—O3^xiv	2.250 (3)
Ba1—O1^iv	2.753 (3)	Y2—O3^i	2.250 (3)
Ba1—O1^v	2.753 (3)	Y2—O3^xviii	2.250 (3)
Ba1—O3^vi	2.862 (3)	Y2—O3^iii	2.250 (3)
Ba1—O1^ii	3.018 (3)	Y2—Ba1^xviii	3.9414 (17)
Ba1—B1^i	3.211 (4)	Y2—Ba1^iii	3.9414 (17)
Ba1—B1^ii	3.211 (4)	Y2—Ba1^i	3.9414 (17)
Ba1—Y2^vii	3.9414 (17)	Y2—Ba1^xix	3.9414 (17)
Y1—O1^viii	2.271 (3)	Y2—Ba1^xiv	3.9414 (17)
Y1—O1^ix	2.271 (3)	B1—O1	1.360 (4)
Y1—O1^x	2.271 (3)	B1—O2	1.406 (4)
Y1—O1^xi	2.271 (3)	B1—O3	1.356 (4)
Y1—O1	2.271 (3)	B1—Ba1^xviii	3.211 (4)
Y1—O1^xii	2.271 (3)	O1—Ba1^xvi	2.753 (3)
Y1—Ba1^xiii	4.0282 (17)	O1—Ba1^xviii	3.018 (3)
Y1—Ba1^xiv	4.0282 (17)	O2—B1^vii	1.406 (4)
Y1—Ba1^xv	4.0282 (17)	O3—Ba1^xviii	2.732 (3)
Y1—Ba1^xvi	4.0282 (17)	O3—Ba1^xiv	2.862 (3)
O3^ii—Ba1—O3^i	153.03 (10)	Ba1^xv—Y1—Ba1^xvi	65.635 (2)
O3^ii—Ba1—O1^iv	75.33 (7)	O1^viii—Y1—Ba1^xvii	41.01 (6)
O3^i—Ba1—O1^iv	129.90 (7)	O1^ix—Y1—Ba1^xvii	138.99 (6)
O3^ii—Ba1—O1^v	129.90 (7)	O1^x—Y1—Ba1^xvii	73.68 (6)
O3^i—Ba1—O1^v	75.33 (7)	O1^xi—Y1—Ba1^xvii	47.86 (6)
O1^iv—Ba1—O1^v	67.33 (10)	O1—Y1—Ba1^xvii	132.14 (6)
O3^ii—Ba1—O3^vi	61.44 (9)	O1^xii—Y1—Ba1^xvii	106.32 (6)
O3^i—Ba1—O3^vi	116.25 (7)	Ba1^xiii—Y1—Ba1^xvii	65.635 (2)
O1^iv—Ba1—O3^vi	96.75 (7)	Ba1^xiv—Y1—Ba1^xvii	114.365 (2)
O1^v—Ba1—O3^vi	90.57 (7)	Ba1^xv—Y1—Ba1^xvii	65.635 (2)
O3^ii—Ba1—O3^iii	116.25 (7)	Ba1^xvi—Y1—Ba1^xvii	114.365 (2)
O3^i—Ba1—O3^iii	61.44 (9)	O1^viii—Y1—Ba1^xviii	138.99 (6)
O1^iv—Ba1—O3^iii	90.57 (7)	O1^ix—Y1—Ba1^xviii	41.01 (6)
O1^v—Ba1—O3^iii	96.75 (7)	O1^x—Y1—Ba1^xviii	106.32 (6)
O3^vi—Ba1—O3^iii	171.22 (9)	O1^xi—Y1—Ba1^xviii	132.14 (6)
O3^ii—Ba1—O2	76.52 (5)	O1—Y1—Ba1^xviii	47.86 (6)
O3^i—Ba1—O2	76.52 (5)	O1^xii—Y1—Ba1^xviii	73.68 (6)
O1^iv—Ba1—O2	146.33 (5)	Ba1^xiii—Y1—Ba1^xviii	114.365 (2)
O1^v—Ba1—O2	146.33 (5)	Ba1^xiv—Y1—Ba1^xviii	65.635 (2)
O3^vi—Ba1—O2	85.61 (5)	Ba1^xv—Y1—Ba1^xviii	114.365 (2)
O3^iii—Ba1—O2	85.61 (5)	Ba1^xvi—Y1—Ba1^xviii	65.635 (2)
O3^ii—Ba1—O1^i	128.22 (7)	Ba1^xvii—Y1—Ba1^xviii	180.0
O3^i—Ba1—O1^i	48.60 (7)	O3^xix—Y2—O3	180.00 (9)
O1^iv—Ba1—O1^i	127.59 (2)	O3^xix—Y2—O3^xiv	101.07 (8)
O1^v—Ba1—O1^i	62.75 (9)	O3—Y2—O3^xiv	78.93 (8)
O3^vi—Ba1—O1^i	69.43 (6)	O3^xix—Y2—O3^i	78.93 (8)
O3^iii—Ba1—O1^i	109.72 (6)	O3—Y2—O3^i	101.07 (8)
O2—Ba1—O1^i	84.76 (5)	O3^xiv—Y2—O3^i	180.00 (9)
O3^ii—Ba1—O1^ii	48.60 (7)	O3^xix—Y2—O3^xviii	78.93 (8)
O3^i—Ba1—O1^ii	128.22 (7)	O3—Y2—O3^xviii	101.07 (8)
O1^iv—Ba1—O1^ii	62.75 (9)	O3^xiv—Y2—O3^xviii	78.93 (8)
O1^v—Ba1—O1^ii	127.59 (2)	O3^i—Y2—O3^xviii	101.07 (8)
O3^vi—Ba1—O1^ii	109.72 (6)	O3^xix—Y2—O3^iii	101.07 (8)
O3^iii—Ba1—O1^ii	69.43 (6)	O3—Y2—O3^iii	78.93 (8)
O2—Ba1—O1^ii	84.76 (5)	O3^xiv—Y2—O3^iii	101.07 (8)
O1^i—Ba1—O1^ii	169.52 (9)	O3^i—Y2—O3^iii	78.93 (8)
O3^ii—Ba1—B1^i	141.57 (8)	O3^xviii—Y2—O3^iii	180.00 (10)
O3^i—Ba1—B1^i	24.73 (8)	O3^xix—Y2—Ba1^xviii	137.78 (6)
O1^iv—Ba1—B1^i	138.70 (8)	O3—Y2—Ba1^xviii	42.22 (6)
O1^v—Ba1—B1^i	72.22 (8)	O3^xiv—Y2—Ba1^xviii	45.62 (6)
O3^vi—Ba1—B1^i	91.58 (8)	O3^i—Y2—Ba1^xviii	134.38 (6)
O3^iii—Ba1—B1^i	86.07 (8)	O3^xviii—Y2—Ba1^xviii	70.56 (6)
O2—Ba1—B1^i	74.46 (7)	O3^iii—Y2—Ba1^xviii	109.44 (6)
O1^i—Ba1—B1^i	24.97 (8)	O3^xix—Y2—Ba1^iii	42.22 (6)
O1^ii—Ba1—B1^i	149.05 (8)	O3—Y2—Ba1^iii	137.78 (6)
O3^ii—Ba1—B1^ii	24.73 (8)	O3^xiv—Y2—Ba1^iii	134.38 (6)
O3^i—Ba1—B1^ii	141.57 (8)	O3^i—Y2—Ba1^iii	45.62 (6)
O1^iv—Ba1—B1^ii	72.22 (8)	O3^xviii—Y2—Ba1^iii	109.44 (6)
O1^v—Ba1—B1^ii	138.70 (8)	O3^iii—Y2—Ba1^iii	70.56 (6)
O3^vi—Ba1—B1^ii	86.07 (8)	Ba1^xviii—Y2—Ba1^iii	180.0
O3^iii—Ba1—B1^ii	91.58 (8)	O3^xix—Y2—Ba1	109.44 (6)
O2—Ba1—B1^ii	74.46 (7)	O3—Y2—Ba1	70.56 (6)
O1^i—Ba1—B1^ii	149.05 (8)	O3^xiv—Y2—Ba1	137.78 (6)
O1^ii—Ba1—B1^ii	24.97 (8)	O3^i—Y2—Ba1	42.22 (6)
B1^i—Ba1—B1^ii	148.92 (13)	O3^xviii—Y2—Ba1	134.38 (6)
O3^ii—Ba1—Y2^vii	33.60 (5)	O3^iii—Y2—Ba1	45.62 (6)
O3^i—Ba1—Y2^vii	129.31 (5)	Ba1^xviii—Y2—Ba1	112.731 (2)
O1^iv—Ba1—Y2^vii	99.39 (5)	Ba1^iii—Y2—Ba1	67.269 (2)
O1^v—Ba1—Y2^vii	123.25 (5)	O3^xix—Y2—Ba1^i	45.62 (6)
O3^vi—Ba1—Y2^vii	34.18 (5)	O3—Y2—Ba1^i	134.38 (6)
O3^iii—Ba1—Y2^vii	139.63 (5)	O3^xiv—Y2—Ba1^i	109.44 (6)
O2—Ba1—Y2^vii	64.697 (3)	O3^i—Y2—Ba1^i	70.56 (6)
O1^i—Ba1—Y2^vii	94.85 (5)	O3^xviii—Y2—Ba1^i	42.22 (6)
O1^ii—Ba1—Y2^vii	80.64 (4)	O3^iii—Y2—Ba1^i	137.78 (6)
B1^i—Ba1—Y2^vii	109.55 (6)	Ba1^xviii—Y2—Ba1^i	112.731 (2)
B1^ii—Ba1—Y2^vii	55.69 (7)	Ba1^iii—Y2—Ba1^i	67.269 (2)
O1^viii—Y1—O1^ix	180.0	Ba1—Y2—Ba1^i	112.731 (2)
O1^viii—Y1—O1^x	96.87 (8)	O3^xix—Y2—Ba1^xix	70.56 (6)
O1^ix—Y1—O1^x	83.13 (8)	O3—Y2—Ba1^xix	109.44 (6)
O1^viii—Y1—O1^xi	83.13 (8)	O3^xiv—Y2—Ba1^xix	42.22 (6)
O1^ix—Y1—O1^xi	96.87 (8)	O3^i—Y2—Ba1^xix	137.78 (6)
O1^x—Y1—O1^xi	83.13 (8)	O3^xviii—Y2—Ba1^xix	45.62 (6)
O1^viii—Y1—O1	96.87 (8)	O3^iii—Y2—Ba1^xix	134.38 (6)
O1^ix—Y1—O1	83.13 (8)	Ba1^xviii—Y2—Ba1^xix	67.269 (2)
O1^x—Y1—O1	96.87 (8)	Ba1^iii—Y2—Ba1^xix	112.731 (2)
O1^xi—Y1—O1	180.0	Ba1—Y2—Ba1^xix	180.0
O1^viii—Y1—O1^xii	83.13 (8)	Ba1^i—Y2—Ba1^xix	67.269 (2)
O1^ix—Y1—O1^xii	96.87 (8)	O3^xix—Y2—Ba1^xiv	134.38 (6)
O1^x—Y1—O1^xii	180.0	O3—Y2—Ba1^xiv	45.62 (6)
O1^xi—Y1—O1^xii	96.87 (8)	O3^xiv—Y2—Ba1^xiv	70.56 (6)
O1—Y1—O1^xii	83.13 (8)	O3^i—Y2—Ba1^xiv	109.44 (6)
O1^viii—Y1—Ba1^xiii	106.32 (6)	O3^xviii—Y2—Ba1^xiv	137.78 (6)
O1^ix—Y1—Ba1^xiii	73.68 (6)	O3^iii—Y2—Ba1^xiv	42.22 (6)
O1^x—Y1—Ba1^xiii	47.86 (6)	Ba1^xviii—Y2—Ba1^xiv	67.269 (2)
O1^xi—Y1—Ba1^xiii	41.01 (6)	Ba1^iii—Y2—Ba1^xiv	112.731 (2)
O1—Y1—Ba1^xiii	138.99 (6)	Ba1—Y2—Ba1^xiv	67.269 (2)
O1^xii—Y1—Ba1^xiii	132.14 (6)	Ba1^i—Y2—Ba1^xiv	180.000 (7)
O1^viii—Y1—Ba1^xiv	132.14 (6)	Ba1^xix—Y2—Ba1^xiv	112.731 (2)
O1^ix—Y1—Ba1^xiv	47.86 (6)	O3—B1—O1	122.5 (3)
O1^x—Y1—Ba1^xiv	41.01 (6)	O3—B1—O2	116.3 (3)
O1^xi—Y1—Ba1^xiv	106.32 (6)	O1—B1—O2	121.2 (3)
O1—Y1—Ba1^xiv	73.68 (6)	O3—B1—Ba1^xviii	57.42 (17)
O1^xii—Y1—Ba1^xiv	138.99 (6)	O1—B1—Ba1^xviii	69.53 (18)
Ba1^xiii—Y1—Ba1^xiv	65.635 (2)	O2—B1—Ba1^xviii	159.0 (2)
O1^viii—Y1—Ba1^xv	47.86 (6)	B1—O1—Y1	128.9 (2)
O1^ix—Y1—Ba1^xv	132.14 (6)	B1—O1—Ba1^xvi	123.7 (2)
O1^x—Y1—Ba1^xv	138.99 (6)	Y1—O1—Ba1^xvi	106.23 (9)
O1^xi—Y1—Ba1^xv	73.68 (6)	B1—O1—Ba1^xviii	85.50 (19)
O1—Y1—Ba1^xv	106.32 (6)	Y1—O1—Ba1^xviii	98.24 (8)
O1^xii—Y1—Ba1^xv	41.01 (6)	Ba1^xvi—O1—Ba1^xviii	98.23 (7)
Ba1^xiii—Y1—Ba1^xv	114.365 (2)	B1^vii—O2—B1	122.0 (4)
Ba1^xiv—Y1—Ba1^xv	180.0	B1^vii—O2—Ba1	119.0 (2)
O1^viii—Y1—Ba1^xvi	73.68 (6)	B1—O2—Ba1	119.0 (2)
O1^ix—Y1—Ba1^xvi	106.32 (6)	B1—O3—Y2	140.0 (2)
O1^x—Y1—Ba1^xvi	132.14 (6)	B1—O3—Ba1^xviii	97.9 (2)
O1^xi—Y1—Ba1^xvi	138.99 (6)	Y2—O3—Ba1^xviii	104.18 (9)
O1—Y1—Ba1^xvi	41.01 (6)	B1—O3—Ba1^xiv	107.0 (2)
O1^xii—Y1—Ba1^xvi	47.86 (6)	Y2—O3—Ba1^xiv	100.20 (8)
Ba1^xiii—Y1—Ba1^xvi	180.0	Ba1^xviii—O3—Ba1^xiv	102.59 (8)
Ba1^xiv—Y1—Ba1^xvi	114.365 (2)

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