Crystal structure of the solid solution Ba8.35Pb0.65(B3O6)6

Zhao, W.

doi:10.1107/S2056989017001864

research communications

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 73| Part 3| March 2017| Pages 349-353

https://doi.org/10.1107/S2056989017001864

Open

access

Crystal structure of the solid solution Ba_8.35Pb_0.65(B₃O₆)₆

Wenwu Zhao ^a ^*

^aDepartment of Environmental and Chemical Engineering, Tangshan College, 38 North HuaYan Road, Tangshan 063000, Hebei, People's Republic of China
^*Correspondence e-mail: zww995@163.com

Edited by M. Weil, Vienna University of Technology, Austria (Received 5 December 2016; accepted 2 February 2017; online 14 February 2017)

Single crystals of lead barium borate, Ba_8.35Pb_0.65(B₃O₆)₆, octabarium lead(II) hexakis(triborate), have been obtained by spontaneous nucleation from a high-temperature melt. Its three-dimensional structure is constructed on the basis of a BaO₉ polyhedron, a (Pb/Ba)O₆ octahedron (occupancy ratio Pb:Ba = 0.216:0.784) and a condensed B₃O₆ ring anion. In the crystal, the planar B₃O₆ anions are stacked in an alternating fashion with Ba and (Pb/Ba) atoms along [001]. A comparison is made with the structures of related solid solutions in the system Ba/Pb/B/O.

Keywords: crystal structure; borate; spontaneous nucleation; solid solution.

CCDC reference: 1530747

1. Chemical context

The study of inorganic borates is motivated by their possible non-linear optical properties, transparency in a wide range of wavelengths, high laser-damage tolerance, piezoelectricity and luminescent and other useful properties for technical applications of the respective compounds. For example, β-BaB₂O₄ (Chen et al., 1985 ), LiB₃O₅ (Chen et al., 1989 ), CsB₃O₅ (Sasaki et al., 2000 ), Sr₂Be₂B₂O₇ (Chen et al., 1995 ), K₅Ba₁₀(BO₃)₈F (Liu et al., 2016 ), PbB₄O₇ (Bartwal et al., 2001 ), Pb₂B₅O₉X (X = Cl, Br, I) (Huang et al., 2010 ) or Ba₃Sr₄(BO₃)₃F₅ (Zhang et al., 2009 ) have been studied because of their second-order non-linear optical behavior. Among inorganic borates synthesized and characterized over the past decades, some lead(II) borates show comprehensive applications. These features are associated with the highly asymmetric stereochemistry typical for a lead(II) atom due to the stereoactivity of the 6s² lone pair (Zhang et al., 2016 ; Mutailipu et al., 2016 ). Accordingly, numerous studies have been devoted to this family of compounds. Some lead borates are particularly attractive because of their high second-harmonic generation (SHG) response (Wu et al., 2012 ; Dong et al., 2015 ; Jing et al., 2015 ) or large birefringence (Liu et al., 2015 ).

In this communication, we report on the synthesis and crystal structure of the solid solution Ba_8.35Pb_0.65(B₃O₆)₆.

2. Structural commentary

The crystal structure of Ba_8.35Pb_0.65(B₃O₆)₆ is based on a Ba2O₉ polyhedron, a (Pb/Ba1)O₆ polyhedron and a condensed B₃O₆ anion, as shown in Fig. 1. The planar B₃O₆ anions (point group symmetry 3.) are isolated from each other and distributed layer upon layer perpendicular to [001]. The occupationally disordered (Pb/Ba)1 site (occupancy ratio Pb:Ba = 0.216:0.784) and the Ba2 site are located alternately between the B₃O₆ sheets in (Pb/Ba)1 and Ba2 layers, as shown in Fig. 2a. The B atom is bound to one O1 atom and two O2 atoms to from a BO₃ triangle. Three BO₃ triangles are condensed through vertex-sharing to build a planar and cyclic B₃O₆ unit. The B—O bond lengths vary from 1.318 (5) to 1.406 (5) Å (Table 1), and the O—B—O angles are between 116.8 (4) and 122.6 (4)°.

Table 1
Selected geometric parameters (Å, °)

(Pb/Ba)1—O1	2.537 (3)	B—O1	1.318 (5)
Ba2—O1	2.766 (3)	B—O2	1.397 (5)
Ba2—O1ⁱ	2.810 (3)	B—O2ⁱⁱ	1.406 (5)
Ba2—O2	3.030 (3)

O1—B—O2	120.6 (4)	O2—B—O2ⁱⁱ	116.8 (4)
O1—B—O2ⁱⁱ	122.6 (4)
Symmetry codes: (i) $[-x+{\script{2\over 3}}, -y+{\script{1\over 3}}, -z+{\script{1\over 3}}]$ ; (ii) -y, x-y-1, z.

Figure 1
The principal building units in the crystal structure of the title compound. Displacement ellipsoids are drawn at the 50% probability level. [Symmetry codes: (i) −x, −y, −z; (ii) −y, x − y, z; (iii) y, −x + y, −z; (iv) x − y, x, −z; (v) −x + y, −x, z; (vi) −y + 1, x − y, z; (vii) −x + y + 1, −x + 1, z; (viii) y + $[{2\over 3}]$ , −x + y + $[{1\over 3}]$ , −z + $[{1\over 3}]$ ; (ix) x − y + $[{2\over 3}]$ , x + $[{1\over 3}]$ , −z + $[{1\over 3}]$ ; (x) −x + $[{2\over 3}]$ , −y + $[{1\over 3}]$ , −z + $[{1\over 3}]$ ; (xiii) −y, x − y − 1, z; (xiv) −x + y + 1, −x, z.]

Figure 2
The crystal structures of related solid solutions in the system Ba/Pb/B/O viewed down [010]: (a) Ba_8.35Pb_0.65(B₃O₆)₆; (b) Ba_7.87Pb_1.13(B₃O₆)₆ (Wu et al., 2012

); (c) Ba₂Pb(B₃O₆)₂ (Li et al., 2014

); (d) Ba₂Pb(B₃O₆)₂ (Tang et al., 2015

). The numbers indicate the bond lengths (Å) of the PbO₆ or (Ba/Pb)O₆ octahedra.

The Ba2 atom (site symmetry 3.) is coordinated by nine O atoms. The Ba—O bond lengths of the Ba2O₉ polyhedron range from 2.766 (3) to 3.030 (3) Å, with a mean distance of 2.869 Å (Table 1). A similar environment for Ba is observed in the crystal structures of Na₃Ba₂(B₃O₆)₂F (Zhang et al., 2015 ), PbBa₂(B₃O₆)₂ (Li et al., 2014 ) and α-BBO (Wu et al., 2002 ). Each of the Ba2O₉ polyhedra shares edges with adjacent Ba2O₉ polyhedra to form six-membered rings that are arranged in corrugated layers extending parallel to (001) (Fig. 3). The (Pb/Ba)1 site (site symmetry $[\overline{3}]$ .) is surrounded by six O atoms; the corresponding (Pb/Ba)1O₆ octahedra are isolated from each other. The six (Pb/Ba1)—O bonds have an identical length of 2.537 (3) Å (Table 1, Fig. 2a). In comparison with the M2 site, the M1 site has a more narrow coordination environment which seems to be the reason why Pb atoms exclusively substitute Ba atoms at the latter position due to their smaller ionic radius.

Figure 3
The formation of a corrugated layer of Ba2O₉ polyhedra in the crystal structure of Ba_8.35Pb_0.65(B₃O₆)₆ viewed down [001].

3. Comparison with the structures of related solid solutions

It is interesting to compare the structure of Ba_8.35Pb_0.65(B₃O₆)₆ with those of the related solid solutions Ba_7.87Pb_1.13(B₃O₆)₆ (Wu et al., 2012) and Ba₂Pb(B₃O₆)₂ (Li et al., 2014; Tang et al., 2015 ). Whereas the title compound Ba_8.35Pb_0.65(B₃O₆)₆ crystallizes in space group R $[\overline{3}]$ , Ba_7.87Pb_1.13(B₃O₆)₆ was solved and refined in space group R32 on the basis of single crystal X-ray diffraction data (Wu et al., 2012); the lattice parameters of both compounds are very similar. Ba₂Pb(B₃O₆)₂ on the other hand was reported to crystallize either in space group R $[\overline{3}]$ with lattice parameters in the same range as the previous two structures (single crystal X-ray diffraction data; Li et al., 2014) or in space group R $[\overline{3}]$ c with a doubled c axis in comparison with the other structures (powder X-ray diffraction data using the Rietveld method; Tang et al., 2015). All four crystal structures are characterized by an alternating stacking of cationic and anionic (001) layers along [001], as shown in Fig. 2. In each case, the Ba site is coordinated by nine O atoms to form BaO₉ polyhedra, and the Pb or the (Pb/Ba) site is coordinated by six O atoms to form distorted PbO₆ octahedra [in Ba₂Pb(B₃O₆)₂] or (Pb/Ba)O₆ octahedra [in Ba_8.35Pb_0.65(B₃O₆)₆ and Ba_7.87Pb_1.13(B₃O₆)₆].

The arrangement of the planar B₃O₆ rings in the crystal structures is a determining factor in whether a non-centrosymmetric or a centrosymmetric structure is obtained. In Ba_7.87Pb_1.13(B₃O₆)₆ (Wu et al., 2012), the rings are aligned in a chiral arrangement (Fig. 4b), responsible for the SHG effect. In Ba₂Pb(B₃O₆)₂ (Li et al., 2014), the B₃O₆ rings are parallel to each other, distributed layer upon layer along [001], and the B₃O₆ rings in neighbouring layers point in exactly opposite directions (Fig. 4c), just like in the title compound (Fig. 4a). In the Ba₂Pb(B₃O₆)₂ structure with doubled volume (Tang et al., 2015), all of the B₃O₆ rings are parallel to (001), and the B₃O₆ rings in two neighbouring layers are rotated slightly relative to each other (Fig. 4d).

Figure 4
The arrangement of B₃O₆ groups along the [001] direction in the different solid solutions: (a) Ba_8.35Pb_0.65(B₃O₆)₆; (b) Ba_7.87Pb_1.13(B₃O₆)₆ (Wu et al., 2012

); (c) Ba₂Pb(B₃O₆)₂ (Li et al., 2014

); (d) Ba₂Pb(B₃O₆)₂ (Tang et al., 2015

4. Synthesis and crystallization

Suitable crystals of the solid solution Ba_8.35Pb_0.65(B₃O₆)₆ were obtained by spontaneous nucleation from a high-temperature melt mixture originating from PbO, H₃BO₃ and BaF₂ in molar ratios of 4:5:1. The starting materials were weighed and melted in a platinum crucible in several batches. The crucible position was fixed at the centre of a resistance-heated furnace. The temperature of the furnace was controlled within 0.1–1 K by an Al-708P controller and a Pt/Pt–Rh thermocouple. The temperature was raised by about 50 K h⁻¹ to 50 K above the melting point and held for 15 h to ensure a homogenous mixture of the solution. After cooling down the furnace to 1073 K, a slow cooling rate of 5 K d⁻¹, was applied, followed by cooling to room temperature at 20 K h⁻¹. Colorless crystals in the millimetre range were obtained.

5. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2. From the two large cation positions in the structure (Wyckoff positions 3a and 6c), only those of M1 at 3a are occupationally disordered by Ba and Pb atoms. Refinement of the occupancy of Ba:Pb at this site under consideration of EXYZ and EADP commands (Sheldrick, 2008 ) resulted in a 21.6 (7)% occupancy of Pb. The highest peak and the deepest hole are located 0.98 and 2.06 Å from the Ba2 and B atoms, respectively.

Table 2
Experimental details

Crystal data
Chemical formula	Ba_8.35Pb_0.65(B₃O₆)₆
M_r	2051.83
Crystal system, space group	Trigonal, R $[\overline{3}]$
Temperature (K)	296
a, c (Å)	7.206 (2), 18.653 (11)
V (Å³)	838.7 (6)
Z	1
Radiation type	Mo Kα
μ (mm⁻¹)	13.00
Crystal size (mm)	0.16 × 0.08 × 0.02

Data collection
Diffractometer	Bruker APEXII CCD
Absorption correction	Numerical (face-indexed using SADABS; Bruker, 2000 )
T_min, T_max	0.141, 0.547
No. of measured, independent and observed [I > 2σ(I)] reflections	1745, 441, 430
R_int	0.024
(sin θ/λ)_max (Å⁻¹)	0.652

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.019, 0.048, 1.23
No. of reflections	441
No. of parameters	35
Δρ_max, Δρ_min (e Å⁻³)	0.64, −0.74
Computer programs: APEX2 and SAINT (Bruker, 2000), SHELXS97, SHELXL97 and SHELXTL (Sheldrick, 2008) and DIAMOND (Brandenburg, 2006 ).

Supporting information

CCDC reference: 1530747

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989017001864/wm5348sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989017001864/wm5348Isup2.hkl

Crystal structure. DOI: https://doi.org/10.1107/S2056989017001864/wm5348sup3.txt

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2000); cell refinement: SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); 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: SHELXTL (Sheldrick, 2008).

Octabarium lead(II) hexakis(triborate) top

Crystal data top

Ba_8.35Pb_0.65(B₃O₆)₆	D_x = 4.062 Mg m⁻³
M_r = 2051.83	Mo Kα radiation, λ = 0.71073 Å
Trigonal, R3	Cell parameters from 1161 reflections
Hall symbol: -R 3	θ = 3.3–27.6°
a = 7.206 (2) Å	µ = 13.00 mm⁻¹
c = 18.653 (11) Å	T = 296 K
V = 838.7 (6) Å³	Plate, colourless
Z = 1	0.16 × 0.08 × 0.02 mm
F(000) = 899

Data collection top

Bruker APEXII CCD diffractometer	441 independent reflections
Radiation source: fine-focus sealed tube	430 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.024
phi and ω scans	θ_max = 27.6°, θ_min = 3.3°
Absorption correction: numerical (face-indexed using SADABS; Bruker, 2000)	h = −8→9
T_min = 0.141, T_max = 0.547	k = −9→9
1745 measured reflections	l = −14→23

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.019	w = 1/[σ²(F_o²) + (0.0178P)² + 5.852P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.048	(Δ/σ)_max < 0.001
S = 1.23	Δρ_max = 0.64 e Å⁻³
441 reflections	Δρ_min = −0.74 e Å⁻³
35 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.00125 (17)

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.

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 (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Pb1	0.0000	0.0000	0.0000	0.0147 (2)	0.216 (7)
Ba1	0.0000	0.0000	0.0000	0.0147 (2)	0.784 (7)
Ba2	0.6667	0.3333	0.12947 (2)	0.01537 (18)
B	0.2953 (7)	−0.1579 (7)	0.0864 (3)	0.0175 (9)
O1	0.2633 (5)	0.0063 (4)	0.09165 (18)	0.0218 (6)
O2	0.5029 (5)	−0.1261 (5)	0.08345 (18)	0.0234 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Pb1	0.0136 (2)	0.0136 (2)	0.0169 (3)	0.00680 (12)	0.000	0.000
Ba1	0.0136 (2)	0.0136 (2)	0.0169 (3)	0.00680 (12)	0.000	0.000
Ba2	0.01176 (19)	0.01176 (19)	0.0226 (3)	0.00588 (9)	0.000	0.000
B	0.019 (2)	0.017 (2)	0.018 (2)	0.0103 (18)	−0.0009 (18)	−0.0002 (17)
O1	0.0185 (14)	0.0159 (13)	0.0320 (17)	0.0093 (12)	−0.0011 (12)	−0.0022 (12)
O2	0.0162 (14)	0.0142 (13)	0.0384 (18)	0.0066 (11)	0.0012 (13)	0.0017 (13)

Geometric parameters (Å, º) top

(Pb/Ba)1—O1ⁱ	2.537 (3)	Ba2—O1^vii	2.810 (3)
(Pb/Ba)1—O1ⁱⁱ	2.537 (3)	Ba2—O2	3.030 (3)
(Pb/Ba)1—O1	2.537 (3)	Ba2—O2^viii	3.030 (3)
(Pb/Ba)1—O1ⁱⁱⁱ	2.537 (3)	Ba2—O2^ix	3.030 (3)
(Pb/Ba)1—O1^iv	2.537 (3)	Ba2—B^viii	3.296 (5)
(Pb/Ba)1—O1^v	2.537 (3)	Ba2—B^ix	3.296 (5)
Pb1—Ba2^vi	3.803 (2)	Ba2—Pb1^xii	3.803 (2)
Pb1—Ba2^vii	3.803 (2)	B—O1	1.318 (5)
Ba2—O1^viii	2.766 (3)	B—O2	1.397 (5)
Ba2—O1	2.766 (3)	B—O2^xiii	1.406 (5)
Ba2—O1^ix	2.766 (3)	O1—Ba2^vii	2.810 (3)
Ba2—O1^x	2.810 (3)	O2—B^xiv	1.406 (5)
Ba2—O1^xi	2.810 (3)

O1ⁱ—Pb1—O1ⁱⁱ	100.43 (11)	O1^xi—Ba2—O2^viii	67.48 (9)
O1ⁱ—Pb1—O1	180.00 (17)	O1^vii—Ba2—O2^viii	135.55 (8)
O1ⁱⁱ—Pb1—O1	79.57 (11)	O2—Ba2—O2^viii	112.31 (6)
O1ⁱ—Pb1—O1ⁱⁱⁱ	79.57 (11)	O1^viii—Ba2—O2^ix	147.14 (9)
O1ⁱⁱ—Pb1—O1ⁱⁱⁱ	180.00 (11)	O1—Ba2—O2^ix	67.39 (8)
O1—Pb1—O1ⁱⁱⁱ	100.43 (11)	O1^ix—Ba2—O2^ix	47.75 (8)
O1ⁱ—Pb1—O1^iv	79.57 (11)	O1^x—Ba2—O2^ix	135.55 (8)
O1ⁱⁱ—Pb1—O1^iv	100.43 (11)	O1^xi—Ba2—O2^ix	107.59 (8)
O1—Pb1—O1^iv	100.43 (11)	O1^vii—Ba2—O2^ix	67.48 (9)
O1ⁱⁱⁱ—Pb1—O1^iv	79.57 (11)	O2—Ba2—O2^ix	112.31 (6)
O1ⁱ—Pb1—O1^v	100.43 (11)	O2^viii—Ba2—O2^ix	112.31 (6)
O1ⁱⁱ—Pb1—O1^v	79.57 (11)	O1^viii—Ba2—B^viii	23.05 (10)
O1—Pb1—O1^v	79.57 (11)	O1—Ba2—B^viii	134.00 (10)
O1ⁱⁱⁱ—Pb1—O1^v	100.43 (11)	O1^ix—Ba2—B^viii	92.24 (10)
O1^iv—Pb1—O1^v	180.00 (17)	O1^x—Ba2—B^viii	89.14 (10)
O1ⁱ—Pb1—Ba2^vi	47.64 (7)	O1^xi—Ba2—B^viii	75.27 (10)
O1ⁱⁱ—Pb1—Ba2^vi	132.36 (7)	O1^vii—Ba2—B^viii	144.45 (11)
O1—Pb1—Ba2^vi	132.36 (7)	O2—Ba2—B^viii	89.88 (9)
O1ⁱⁱⁱ—Pb1—Ba2^vi	47.64 (7)	O2^viii—Ba2—B^viii	25.06 (9)
O1^iv—Pb1—Ba2^vi	47.64 (7)	O2^ix—Ba2—B^viii	134.51 (10)
O1^v—Pb1—Ba2^vi	132.36 (7)	O1^viii—Ba2—B^ix	134.00 (10)
O1ⁱ—Pb1—Ba2^vii	132.36 (7)	O1—Ba2—B^ix	92.24 (10)
O1ⁱⁱ—Pb1—Ba2^vii	47.64 (7)	O1^ix—Ba2—B^ix	23.05 (10)
O1—Pb1—Ba2^vii	47.64 (7)	O1^x—Ba2—B^ix	144.45 (11)
O1ⁱⁱⁱ—Pb1—Ba2^vii	132.36 (7)	O1^xi—Ba2—B^ix	89.14 (10)
O1^iv—Pb1—Ba2^vii	132.36 (7)	O1^vii—Ba2—B^ix	75.27 (10)
O1^v—Pb1—Ba2^vii	47.64 (7)	O2—Ba2—B^ix	134.51 (10)
Ba2^vi—Pb1—Ba2^vii	180.0	O2^viii—Ba2—B^ix	89.88 (10)
O1^viii—Ba2—O1	113.73 (6)	O2^ix—Ba2—B^ix	25.06 (9)
O1^viii—Ba2—O1^ix	113.73 (6)	B^viii—Ba2—B^ix	114.27 (7)
O1—Ba2—O1^ix	113.73 (6)	O1^viii—Ba2—Pb1^xii	104.78 (7)
O1^viii—Ba2—O1^x	76.27 (10)	O1—Ba2—Pb1^xii	104.78 (7)
O1—Ba2—O1^x	89.15 (12)	O1^ix—Ba2—Pb1^xii	104.78 (7)
O1^ix—Ba2—O1^x	145.30 (7)	O1^x—Ba2—Pb1^xii	41.85 (7)
O1^viii—Ba2—O1^xi	89.15 (12)	O1^xi—Ba2—Pb1^xii	41.85 (7)
O1—Ba2—O1^xi	145.30 (7)	O1^vii—Ba2—Pb1^xii	41.85 (7)
O1^ix—Ba2—O1^xi	76.27 (10)	O2—Ba2—Pb1^xii	106.46 (7)
O1^x—Ba2—O1^xi	70.59 (10)	O2^viii—Ba2—Pb1^xii	106.46 (7)
O1^viii—Ba2—O1^vii	145.31 (7)	O2^ix—Ba2—Pb1^xii	106.46 (7)
O1—Ba2—O1^vii	76.27 (10)	B^viii—Ba2—Pb1^xii	104.10 (8)
O1^ix—Ba2—O1^vii	89.15 (12)	B^ix—Ba2—Pb1^xii	104.10 (8)
O1^x—Ba2—O1^vii	70.59 (10)	O1—B—O2	120.6 (4)
O1^xi—Ba2—O1^vii	70.59 (10)	O1—B—O2^xiii	122.6 (4)
O1^viii—Ba2—O2	67.39 (8)	O2—B—O2^xiii	116.8 (4)
O1—Ba2—O2	47.75 (8)	B—O1—Pb1	113.5 (3)
O1^ix—Ba2—O2	147.14 (9)	B—O1—Ba2	101.7 (3)
O1^x—Ba2—O2	67.48 (9)	Pb1—O1—Ba2	130.17 (12)
O1^xi—Ba2—O2	135.55 (8)	B—O1—Ba2^vii	117.4 (3)
O1^vii—Ba2—O2	107.59 (8)	Pb1—O1—Ba2^vii	90.51 (10)
O1^viii—Ba2—O2^viii	47.75 (8)	Ba2—O1—Ba2^vii	103.73 (10)
O1—Ba2—O2^viii	147.14 (9)	B—O2—B^xiv	122.9 (4)
O1^ix—Ba2—O2^viii	67.39 (8)	B—O2—Ba2	88.2 (2)
O1^x—Ba2—O2^viii	107.59 (8)	B^xiv—O2—Ba2	143.4 (3)

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

Funding information

Funding for this research was provided by: Discipline Construction Foundation of Tangshan College (award No. tsbc2013003).

References

Bartwal, K. S., Bhatt, R., Kar, S. & Wadhawan, V. K. (2001). Mater. Sci. Eng. B, 85, 76–79. Web of Science CrossRef Google Scholar
Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2000). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chen, C., Wang, Y., Wu, B., Wu, K., Zeng, W. & Yu, L. (1995). Nature, 373, 322–324. CrossRef CAS Web of Science Google Scholar
Chen, C., Wu, Y., Jiang, A., Wu, B., You, G., Li, R. & Lin, S. (1989). J. Opt. Soc. Am. B, 6, 616–621. CrossRef CAS Web of Science Google Scholar
Chen, C., Wu, B., Jiang, A. & You, G. (1985). Sci. Sin. B28, 235–241. Google Scholar
Dong, X. Y., Jing, Q., Shi, Y. J., Yang, Z. H., Pan, S. L., Poeppelmeier, K. R., Young, J. & Rondinelli, J. M. (2015). J. Am. Chem. Soc. 137, 9417–9422. Web of Science CSD CrossRef CAS PubMed Google Scholar
Huang, Y., Wu, L., Wu, X., Li, L., Chen, L. & Zhang, Y. (2010). J. Am. Chem. Soc. 132, 12788–12789. Web of Science CSD CrossRef CAS PubMed Google Scholar
Jing, Q., Dong, X. Y., Yang, Z. H. & Pan, S. L. (2015). Dalton Trans. 44, 16818–16823. Web of Science CrossRef CAS PubMed Google Scholar
Li, H. Y., Dong, L., Lu, Y., Pan, S. L., Lu, X., Yu, H. W., Wu, H. P., Su, X. & Yang, Z. H. (2014). J. Alloys Compd. 615, 561–565. Web of Science CrossRef CAS Google Scholar
Liu, L. L., Yang, Y., Jing, Q., Dong, X. Y., Yang, Z. H., Pan, S. L. & Wu, K. (2016). J. Phys. Chem. C, 120, 18763–18770. Web of Science CrossRef CAS Google Scholar
Liu, L., Zhang, B. B., Zhang, F. F., Pan, S. L., Zhang, F. Y., Zhang, X. W., Dong, X. Y. & Yang, Z. H. (2015). Dalton Trans. 44, 7041–7047. Web of Science CSD CrossRef CAS PubMed Google Scholar
Mutailipu, M., Hou, D. W., Zhang, M., Yang, Z. H. & Pan, S. L. (2016). New J. Chem. 40, 6120–6126. Web of Science CrossRef CAS Google Scholar
Sasaki, T., Mori, Y., Yoshimura, M., Yap, Y. K. & Kamimura, T. (2000). Mater. Sci. Eng. Rep. 30, 1–54. Web of Science CrossRef Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Tang, X. L., Feng, D. X., Wan, S. M., Kang, L., Zhang, B. & Lin, Z. S. (2015). Mater. Chem. Phys. 163, 501–506. Web of Science CrossRef CAS Google Scholar
Wu, H. P., Pan, S. L., Jia, D. Z., Chen, Z. H. & Yu, H. W. (2012). Chem. Lett. 41, 812–813. Web of Science CrossRef CAS Google Scholar
Wu, S., Wang, G., Xie, J., Wu, X., Zhang, Y. & Lin, X. (2002). J. Cryst. Growth, 245, 84–86. Web of Science CrossRef CAS Google Scholar
Zhang, G., Liu, Z., Zhang, J., Fan, F., Liu, Y. & Fu, P. (2009). Cryst. Growth Des. 9, 3137–3141. Web of Science CrossRef CAS Google Scholar
Zhang, F. F., Zhang, F. Y., Lei, B. H., Yang, Z. H. & Pan, S. L. (2016). J. Phys. Chem. C, 120, 12757–12764. Web of Science CrossRef CAS Google Scholar
Zhang, H., Zhang, M., Pan, S. L., Yang, Z., Wang, Z., Bian, Q., Hou, X., Yu, H., Zhang, F., Wu, K., Yang, F., Peng, Q., Xu, Z., Chang, K. B. & Poeppelmeier, K. R. (2015). Cryst. Growth Des. 15, 523–529. Web of Science CrossRef Google Scholar