K₉Y₃[Si₁₂O₃₂]F₂

Single-crystals of the title compound, nona­potassium triyttrium dodeca­silicate difluoride, were obtained from flux synthesis experiments in the system SiO₂—Y₂O₃—KF. The crystal structure belongs to the group of single-layer silicates and is based on silicate sheets parallel to (110). A single layer contains secondary (Q²) and tertiary (Q³) silicate tetra­hedra in the ratio 1:2 and is build up from six-, eight- and twelve-membered rings. The linkage between neighboring layers is achieved by two crystallographically independent Y³⁺ cations, which are coordinated by six oxygen ligands in form of distorted octa­hedra. Charge compensation is accomplished by incorporation of additional F⁻ anions and K⁺ cations in the structural channels, forming anion-centred [F₂K₇] groups. Apart from one K⁺ and one Y³⁺ cation (each with site symmetry -1), the 30 crystallographically independent atoms reside on general positions.

Related literature

Oxosilicates which can serve as luminescent materials containing trivalent rare earth elements, monovalent alkali cations as well as fluorine anions have already been characterized (Jacobsen & Meyer, 1994; Tang et al., 2008; Schäfer & Schleid, 2007, 2011). For structures isotypic to that of the title compound, see: Tang et al. (2008). For general aspects of the crystal chemistry of silicates, see: Liebau (1985). For the definition of distortion parameters, see: Robinson et al. (1971). For bond-valence analysis, see: Brown & Altermatt (1985). For the Inorganic Crystal Structure Database, see: ICSD (2013).

Experimental

Crystal data

• K₉Y₃[Si₁₂O₃₂]F₂

• M_r = 1505.71

• Triclinic,

• a = 6.8187 (3) Å

• b = 11.3345 (4) Å

• c = 11.3727 (5) Å

• α = 87.846 (3)°

• β = 89.747 (4)°

• γ = 80.524 (3)°

• V = 866.35 (6) ų

• Z = 1

• Mo Kα radiation

• μ = 6.60 mm⁻¹

• T = 298 K

• 0.12 × 0.09 × 0.05 mm

Data collection

• Oxford Diffraction Xcalibur diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2006) T_min = 0.801, T_max = 1

• 10508 measured reflections

• 2842 independent reflections

• 2231 reflections with I > 2σ(I)

• R_int = 0.066

Refinement

• R[F² > 2σ(F²)] = 0.039

• wR(F²) = 0.099

• S = 1.08

• 2842 reflections

• 265 parameters

• Δρ_max = 0.87 e Å⁻³

• Δρ_min = −0.95 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2006); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ATOMS for Windows (Dowty, 2011); software used to prepare material for publication: publCIF (Westrip, 2010) and WinGX (Farrugia, 2012).

Supporting information

S1. Comment

In the present paper we describe a previously unknown phase of the system KF—Y₂O₃—SiO₂. According to Liebau's classification (1985) the crystal structure of the title compound, K₉Y₃[Si₁₂O₃₂]F₂, belongs to the group of open-branched single-layer silicates. The more detailed crystallochemical formula can be written as K₉Y₃{oB,1²_∞}[⁵Si₁₂O₃₂]F₂. A single-layer of silicate tetrahedra expands parallel to (110) and is constructed from the condensation of fünfer single chains (Fig. 1). One discrete chain is running parallel to [001] and has a translation period of 11.3727 (5) Å. Each layer contains secondary (Q²) and tertiary (Q³) SiO₄ tetrahedra in the ratio of 1:2 (Fig. 2). The Si—O distances of the six crystallographically independent tetrahedra within the asymmetric unit range from 1.574 (5) to 1.662 (5) Å. As one would expect, the Si—O_terminal bonds are considerably shorter than the distances between Si and the bridging O atoms. The O—Si—O angles show a significant scatter throughout all present polyhedra. Nevertheless, the values are in the expected limits for [SiO₄] units (Liebau, 1985). Numerically, the degree of distortion can be expressed by the quadratic elongation λ and the angle variance σ² (Robinson et al., 1971). For the six tetrahedra, these two parameters vary between 1.003 and 1.005 (for λ) and 8.50 and 20.17 (for σ²) indicating that the deviation from regularity is not very pronounced.

Within the corrugated silicate sheets, six-, eight- and twelve-membered rings can be identified (Fig. 2). The vertex symbols for the [SiO₄] tetrahedra are as follows: 6.8.12 (for Si2, Si3, Si4 and Si6) and 6.12 (for Si1 and Si5). A schematic representation of the arrangement of the rings within a single layer is given in Fig. 2. Charge balance in the structure is achieved by the incorporation of K⁺ and Y³⁺ cations as well as additional F^- anions. Y1 resides on an inversion center and is coordinated by six oxygen ligands belonging to six different [SiO₄]-tetrahedra (Fig. 3). Within the resulting octahedron, the Y—O bond lengths range from 2.237 (4) - 2.256 (4) Å. Y2 is also octahedrally coordinated (Fig. 4). However, each two adjacent [Y2O₆]-octahedra form dimers by sharing one common edge (Fig. 6). Therefore, the spread in the Y—O bond lengths is more siginificant (2.211 (4) - 2.345 (4) Å) which is also reflected in higher values for the distortion parameters: λ = 1.046 and σ² = 149.49 (for Y2), and λ = 1.006 and σ² = 20.88 (for Y1), respectively. The volumes of both octahedra are almost identical: 14.545 ų (for Y2) and 14.991 ų (for Y1). The coordination numbers of the potassium cations are as follows: K1, K2: 8-coordinate, including one F atom; K3: 7-coordinate, including one F atom; K4: 8-coordinate, including two F atoms; K5: 7-coordinate, only O atoms. A slightly different understanding of the structure can be obtained when anion-centred polyhedra are considered as well for the description. Actually, each F^- has four nearest potassium neighbors in form of a tetrahedron. Two symmetry-equivalent tetrahedra are joined by a common corner (K4) into [F₂K₇]-double tetrahedra with point group symmetry 1 (Fig. 5). A side view of the whole structure is given in Fig. 7.

Bond valence sum calculations using the parameter sets for the K—O, K—F, Y—O and Si—O bonds given by Brown & Altermatt (1985) resulted in the following values (in v.u.) considering cation—anion interactions up to 3.4 Å: K1: 0.924, K2: 0.957, K3: 0.844, K4: 0.772, K5: 1.057, Y1: 3.242, Y2: 3.087, Si1: 4.264, Si2: 4.257, Si3: 4.347, Si4: 4.342, Si5: 4.251, and Si6: 4.326.

The present compound is isostructural with a series of rare earth fluoride silicates: K₉(REE)₃[Si₁₂O₃₂]F₂ (REE: Sm, Eu, Gd; Tang et al., 2008). Chemically related compounds include the following phases: KEu₂[Si₄O₁₀]F (Jacobsen & Meyer, 1994), Cs₂Y[Si₄O₁₀]F (Schäfer & Schleid, 2007) and Rb₃Sc₂[Si₄O₁₀]F₅ (Schäfer & Schleid, 2011).

Related literature

Materials which can serve as host structures for luminescent oxosilicates containing trivalent rare earth elements, monovalent alkali cations as well as fluorine anions have been characterized (Jacobsen & Meyer, 1994; Tang et al., 2008; Schäfer & Schleid, 2007, 2011). For structures isotypic to that of the title compound, see: Tang et al. (2008). For general aspects of the crystal chemistry of silicates, see: Liebau (1985). For the definition of distortion parameters, see: Robinson et al. (1971). For bond-valence analysis, see: Brown & Altermatt (1985). For the Inorganic Crystal Structure Database, see: ICSD (2013).

S2. Experimental

Single-crystals of K₉Y₃[Si₁₂O₃₂]F₂ were obtained during a series of flux syntheses experiments aiming on the preparation of new K(REE)-silicate fluorides. 0.1 g of the nutrient consisting of a mixture of Y₂O₃:SiO₂ in the molar ratio 1:4 was homogenized in an agate mortar with 0.1 g KF, transferred into a platinum tube and welded shut. The container was fired in a resistance heated furnace from 373 K to 1373 K with a ramp of 50 K/h. The target temperature was held for 2 h. Subsequently, the sample was cooled down to 1073 K with a rate of 5 K/h and, finally, the temperature was reduced to 373 K with a rate of 100 K/h. The solidified melt cake was immediately crushed in an agate mortar and transferred to a glass slide under a polarizing binocular. A first optical inspection revealed the presence of two phases: a polycrystalline matrix of KF in which transparent birefrigent single-crystals up to 200 µm in size were embedded. However, a closer investigation using crossed polarizers revealed that all crystals showed a fine-scale non-merohedral twinning, making it impossible to separate a specimen consisting of only one domain state. Therefore, we finally decided to use a twinned fragment for further structural studies. The crystal was mounted on the tip of a glass fibre using finger nail hardener as glue.

S3. Refinement

The diffraction patterns were collected at ambient temperature using on Oxford Diffraction Gemini R Ultra single-crystal diffractometer. They showed the expected complexity due to overlapping of two different reciprocal lattices. Nevertheless, it was possible to index the reflections from both domains with the same triclinic unit cell but in different orientations. From the fact that the angle β is close to 90°, the non-merohedral twinning can be readily understood. Similar sets of lattice parameters could be found in the recent WEB-based version of the Inorganic Crystal Structure Database (ICSD, 2013) for the chemically closely related compounds K₉(REE)₃[Si₁₂O₃₂]F₂ (REE = Sm, Eu, Gd) pointing to an isostructural relationship, which was confirmed by the subsequent structure analysis. For structure determination a full data set (sphere) of reciprocal space was collected. Different integration strategies were tested to handle the problem of the partially overlapping reflections of both domains, i.e. a series of data sets was produced in which the overlap threshold was varied stepwise. Different HKLF 5 data sets produced during integration were considered for the refinement of the structure. However, the best results concerning residuals and overall crystallochemical characteristics of the structure were obtained when the data set of only the main twin component (representating about 70% of the total volume) was used, i.e. the completely or partially overlapping reflections have been neglected. However, this approach resulted in a completeness of only 90%.

Computing details

Data collection: CrysAlis PRO (Oxford Diffraction, 2006); cell refinement: CrysAlis PRO (Oxford Diffraction, 2006); data reduction: CrysAlis PRO (Oxford Diffraction, 2006); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ATOMS for Windows (Dowty, 2011); software used to prepare material for publication: publCIF (Westrip, 2010) and WinGX (Farrugia, 2012).

Figures

	Fig. 1. A single silicate layer consisting of [SiO4] tetrahedra in a projection perpendicular to (110).
	Fig. 2. Connectivity of the silicon atoms within a single layer. Red and blue spheres represent Q^3- and Q^2-connected atoms, respectively. The sizes of the different ring types are indicated.
	Fig. 3. Representation of the coordination polyhedron around Y1. Ellipsoids are drawn at the 60% level. [Symmetry codes: (i) 1 - x,-y, 1 - z; (ii) -1 + x,y,z; (iii) -x,-y,1 - z; (iv) 1 - x,1 - y,1 - z; (v) x,1 + y,z; (vi) 1 + x,1 + y,z; (vii) 1 - x,-y,-z.]
	Fig. 4. Representation of the coordination polyhedron around Y2. Ellipsoids are drawn at the 60% level. Symmetry codes: [(i) 1 - x,-y, 1 - z; (ii) -1 + x,y,z; (iii) -x,-y,1 - z; (iv) 1 - x,1 - y,1 - z; (v) x,1 + y,z; (vi) 1 + x,1 + y,z; (vii) 1 - x,-y,-z.]
	Fig. 5. Representation of a single [F2K7]-group. Ellipsoids are drawn at the 60% level. [Symmetry codes: (i) 1 - x,-y, 1 - z; (ii) -1 + x,y,z; (iii) -x,-y,1 - z; (iv) 1 - x,1 - y,1 - z; (v) x,1 + y,z; (vi) 1 + x,1 + y,z; (vii) 1 - x,-y,-z.]
	Fig. 6. The dimer formed from the condensation of two edge-sharing [Y2O6]-octahedra.
	Fig. 7. Side view of the whole crystal structure of K9Y3[Si12O32]F2. [SiO4]- and [YO6]-polyhedra are shown in light-grey and blue. Small grey spheres represent oxygen atoms. Fluorine and potassium ions are given as larger green and pink spheres. F—K bonds of the [F2K7]-double tetrahedra are indicated.

Nonapotassium triyttrium dodecasilicate difluoride

Crystal data

F2K9O32Si12Y3	Z = 1
Mr = 1505.71	F(000) = 730
Triclinic, P1	Dx = 2.886 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.8187 (3) Å	Cell parameters from 4373 reflections
b = 11.3345 (4) Å	θ = 3.0–29.3°
c = 11.3727 (5) Å	µ = 6.60 mm^−1
α = 87.846 (3)°	T = 298 K
β = 89.747 (4)°	Fragment, colourless
γ = 80.524 (3)°	0.12 × 0.09 × 0.05 mm
V = 866.35 (6) Å^3

Data collection

Oxford Diffraction Xcalibur diffractometer	2842 independent reflections
Graphite monochromator	2231 reflections with I > 2σ(I)
Detector resolution: 10.3575 pixels mm^-1	Rint = 0.066
ω scans	θmax = 25.4°, θmin = 3.3°
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2006)	h = −8→8
Tmin = 0.801, Tmax = 1	k = −13→13
10508 measured reflections	l = −13→13

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.039	Secondary atom site location: difference Fourier map
wR(F^2) = 0.099	w = 1/[σ^2(Fo^2) + (0.0515P)^2 + 0.2439P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
2842 reflections	Δρmax = 0.87 e Å^−3
265 parameters	Δρmin = −0.95 e Å^−3

Special details

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'s 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 > 2σ(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
K1	0.2651 (3)	−0.38667 (12)	0.01644 (15)	0.0222 (4)
K2	0.1715 (2)	−0.19454 (12)	−0.22364 (14)	0.0184 (4)
K3	0.1624 (3)	−0.15506 (14)	0.21410 (15)	0.0277 (4)
K4	0.5	0	0	0.0334 (6)
K5	0.0227 (2)	0.33078 (11)	0.51133 (13)	0.0161 (3)
F1	0.2472 (7)	−0.1589 (3)	−0.0048 (4)	0.0256 (10)
Y1	0	0	0.5	0.0068 (2)
Y2	0.48856 (9)	0.48851 (5)	0.33734 (5)	0.00691 (17)
Si1	0.5571 (3)	0.23257 (13)	0.51056 (15)	0.0072 (4)
Si2	0.3376 (3)	0.13524 (14)	0.31036 (16)	0.0077 (4)
Si3	0.6564 (3)	−0.09115 (13)	0.30291 (15)	0.0071 (4)
Si4	0.6897 (3)	−0.30506 (13)	0.15893 (16)	0.0076 (4)
Si5	−0.0138 (3)	−0.51249 (14)	0.25833 (15)	0.0077 (4)
Si6	0.2872 (3)	−0.66727 (14)	0.12015 (16)	0.0079 (4)
O1	0.5290 (7)	0.3756 (3)	0.5151 (4)	0.0115 (10)
O2	0.4907 (6)	0.2083 (3)	0.3742 (4)	0.0113 (10)
O3	0.3903 (6)	0.1857 (3)	0.5954 (4)	0.0097 (9)
O4	0.7743 (6)	0.1627 (3)	0.5395 (4)	0.0107 (10)
O5	0.1448 (7)	0.1240 (3)	0.3837 (4)	0.0125 (10)
O6	0.2791 (7)	0.2030 (3)	0.1831 (4)	0.0129 (10)
O7	0.4575 (7)	0.0054 (3)	0.2739 (4)	0.0132 (10)
O8	0.6920 (7)	−0.1638 (3)	0.1818 (4)	0.0102 (10)
O9	0.8444 (7)	−0.0336 (3)	0.3338 (4)	0.0114 (10)
O10	0.9033 (7)	−0.3743 (3)	0.2102 (4)	0.0139 (10)
O11	0.6983 (7)	−0.3156 (3)	0.0189 (4)	0.0169 (11)
O12	0.5030 (7)	−0.3527 (3)	0.2148 (4)	0.0123 (10)
O13	0.1635 (7)	−0.5084 (3)	0.3462 (4)	0.0114 (10)
O14	−0.1887 (6)	−0.5722 (3)	0.3149 (4)	0.0121 (10)
O15	0.0686 (7)	−0.5849 (3)	0.1393 (4)	0.0131 (10)
O16	0.4610 (7)	−0.6045 (3)	0.1658 (4)	0.0123 (10)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
K1	0.0222 (9)	0.0215 (8)	0.0233 (10)	−0.0056 (6)	0.0004 (7)	0.0030 (6)
K2	0.0165 (9)	0.0192 (7)	0.0197 (9)	−0.0036 (6)	0.0005 (7)	0.0013 (6)
K3	0.0204 (10)	0.0421 (10)	0.0197 (9)	−0.0011 (7)	0.0057 (8)	−0.0068 (7)
K4	0.0395 (17)	0.0363 (13)	0.0280 (15)	−0.0195 (11)	−0.0105 (12)	0.0117 (10)
K5	0.0190 (9)	0.0132 (7)	0.0158 (9)	−0.0020 (6)	0.0035 (7)	−0.0012 (5)
F1	0.030 (3)	0.026 (2)	0.022 (2)	−0.0079 (18)	0.004 (2)	−0.0013 (17)
Y1	0.0038 (5)	0.0078 (4)	0.0086 (5)	−0.0007 (3)	0.0021 (4)	−0.0001 (3)
Y2	0.0032 (3)	0.0093 (3)	0.0082 (3)	−0.0010 (2)	0.0010 (2)	0.0001 (2)
Si1	0.0056 (10)	0.0072 (8)	0.0087 (10)	−0.0010 (6)	0.0009 (7)	0.0006 (6)
Si2	0.0053 (10)	0.0080 (8)	0.0099 (9)	−0.0017 (6)	0.0002 (7)	−0.0003 (6)
Si3	0.0038 (9)	0.0078 (8)	0.0101 (10)	−0.0015 (6)	0.0015 (7)	−0.0010 (6)
Si4	0.0064 (10)	0.0076 (8)	0.0089 (9)	−0.0012 (6)	0.0010 (7)	−0.0011 (6)
Si5	0.0035 (9)	0.0104 (8)	0.0087 (9)	0.0002 (6)	0.0009 (7)	−0.0005 (6)
Si6	0.0072 (10)	0.0084 (8)	0.0081 (10)	−0.0014 (6)	0.0014 (7)	−0.0006 (6)
O1	0.017 (3)	0.006 (2)	0.011 (3)	−0.0005 (17)	0.002 (2)	−0.0002 (16)
O2	0.008 (3)	0.014 (2)	0.014 (3)	−0.0057 (17)	−0.001 (2)	−0.0002 (17)
O3	0.009 (3)	0.012 (2)	0.008 (2)	−0.0029 (17)	0.0027 (19)	−0.0004 (17)
O4	0.005 (2)	0.016 (2)	0.011 (3)	−0.0002 (17)	0.0034 (19)	0.0001 (17)
O5	0.010 (3)	0.013 (2)	0.016 (3)	−0.0037 (17)	0.000 (2)	−0.0016 (17)
O6	0.018 (3)	0.012 (2)	0.010 (3)	−0.0063 (18)	0.001 (2)	0.0035 (17)
O7	0.008 (3)	0.009 (2)	0.021 (3)	0.0039 (17)	−0.001 (2)	−0.0031 (18)
O8	0.015 (3)	0.007 (2)	0.008 (2)	−0.0011 (17)	0.003 (2)	0.0002 (16)
O9	0.008 (3)	0.016 (2)	0.011 (3)	−0.0053 (18)	−0.0006 (19)	0.0005 (17)
O10	0.004 (2)	0.012 (2)	0.025 (3)	−0.0003 (17)	−0.003 (2)	0.0032 (18)
O11	0.022 (3)	0.014 (2)	0.015 (3)	−0.0024 (19)	0.004 (2)	−0.0052 (18)
O12	0.009 (3)	0.010 (2)	0.017 (3)	−0.0022 (17)	0.004 (2)	0.0013 (17)
O13	0.006 (2)	0.017 (2)	0.011 (3)	−0.0028 (17)	0.002 (2)	0.0005 (17)
O14	0.004 (2)	0.013 (2)	0.019 (3)	−0.0020 (17)	−0.001 (2)	0.0021 (18)
O15	0.007 (3)	0.018 (2)	0.013 (3)	0.0015 (18)	0.002 (2)	−0.0040 (18)
O16	0.006 (3)	0.017 (2)	0.015 (3)	−0.0054 (17)	0.003 (2)	−0.0045 (17)

Geometric parameters (Å, º)

K1—F1	2.567 (4)	Si1—O3	1.631 (5)
K1—O16^i	2.778 (5)	Si1—O2	1.662 (5)
K1—O12	2.858 (5)	Si2—O5	1.574 (5)
K1—O15^ii	2.956 (5)	Si2—O2	1.625 (4)
K1—O16	3.064 (5)	Si2—O7	1.629 (4)
K1—O15	3.088 (5)	Si2—O6	1.633 (5)
K1—O11	3.188 (5)	Si3—O9	1.578 (4)
K1—O10^iii	3.289 (5)	Si3—O3^vi	1.613 (4)
K1—O11^i	3.382 (4)	Si3—O7	1.623 (4)
K2—F1	2.604 (4)	Si3—O8	1.628 (4)
K2—O9^iv	2.816 (4)	Si4—O12	1.584 (5)
K2—O5^v	2.821 (5)	Si4—O11	1.602 (5)
K2—O2^iv	2.851 (5)	Si4—O10	1.635 (5)
K2—O14^ii	2.861 (4)	Si4—O8	1.635 (4)
K2—O6^v	3.121 (5)	Si5—O13	1.579 (5)
K2—O16^i	3.150 (5)	Si5—O14	1.588 (4)
K2—O15^ii	3.317 (4)	Si5—O10^iii	1.649 (4)
K3—F1	2.554 (5)	Si5—O15	1.657 (5)
K3—O9^iii	2.754 (5)	Si6—O16	1.578 (4)
K3—O4^vi	2.833 (5)	Si6—O11^i	1.601 (5)
K3—O12	2.949 (5)	Si6—O6^xi	1.620 (4)
K3—O7	3.021 (4)	Si6—O15	1.642 (5)
K3—O8^iii	3.248 (5)	O1—Y2^x	2.310 (4)
K3—O10^iii	3.279 (4)	O1—K5^xii	3.321 (5)
K4—F1^iv	2.692 (4)	O2—K2^iv	2.851 (5)
K4—F1	2.692 (4)	O3—Si3^vi	1.613 (4)
K4—O8^iv	2.893 (4)	O4—Y1^xii	2.256 (4)
K4—O8	2.893 (4)	O4—K5^xii	2.759 (4)
K4—O7	3.129 (5)	O4—K3^vi	2.833 (5)
K4—O7^iv	3.129 (5)	O5—K2^v	2.821 (5)
K4—O6^iv	3.330 (4)	O6—Si6^vii	1.620 (4)
K4—O6	3.330 (4)	O6—K2^v	3.121 (5)
K5—O14^vii	2.756 (5)	O8—K3^xii	3.248 (5)
K5—O4^iii	2.759 (4)	O9—Y1^xii	2.247 (4)
K5—O13^viii	2.771 (4)	O9—K3^xii	2.754 (5)
K5—O5	2.810 (4)	O9—K2^iv	2.816 (4)
K5—O13^vii	2.842 (5)	O10—Si5^xii	1.649 (4)
K5—O3	2.907 (5)	O10—K5^vi	3.277 (5)
K5—O10^vi	3.277 (5)	O10—K3^xii	3.279 (4)
K5—O1^iii	3.321 (5)	O10—K1^xii	3.289 (5)
Y1—O5	2.237 (4)	O11—Si6^i	1.601 (5)
Y1—O5^viii	2.237 (4)	O11—K1^i	3.382 (4)
Y1—O9^vi	2.247 (4)	O12—Y2^xi	2.250 (4)
Y1—O9^iii	2.247 (4)	O13—Y2^xi	2.213 (4)
Y1—O4^vi	2.256 (4)	O13—K5^viii	2.771 (4)
Y1—O4^iii	2.256 (4)	O13—K5^xi	2.842 (5)
Y2—O14^ix	2.211 (4)	O14—Y2^xiii	2.211 (4)
Y2—O13^vii	2.213 (4)	O14—K5^xi	2.756 (5)
Y2—O12^vii	2.250 (4)	O14—K2^ii	2.861 (4)
Y2—O16^vii	2.275 (4)	O15—K1^ii	2.956 (5)
Y2—O1^x	2.310 (4)	O15—K2^ii	3.317 (4)
Y2—O1	2.345 (4)	O16—Y2^xi	2.275 (4)
Si1—O4	1.590 (5)	O16—K1^i	2.778 (5)
Si1—O1	1.603 (4)	O16—K2^i	3.150 (5)
O5—Y1—O5^viii	180	O5—Si2—O7	112.2 (2)
O5—Y1—O9^vi	96.02 (15)	O2—Si2—O7	109.0 (2)
O5^viii—Y1—O9^vi	83.98 (15)	O5—Si2—O6	110.5 (3)
O5—Y1—O9^iii	83.98 (15)	O2—Si2—O6	107.2 (2)
O5^viii—Y1—O9^iii	96.02 (15)	O7—Si2—O6	102.9 (2)
O9^vi—Y1—O9^iii	180	O9—Si3—O3^vi	111.7 (2)
O5—Y1—O4^vi	94.15 (15)	O9—Si3—O7	114.3 (2)
O5^viii—Y1—O4^vi	85.85 (15)	O3^vi—Si3—O7	109.8 (2)
O9^vi—Y1—O4^vi	93.05 (15)	O9—Si3—O8	110.7 (2)
O9^iii—Y1—O4^vi	86.95 (15)	O3^vi—Si3—O8	106.9 (2)
O5—Y1—O4^iii	85.85 (15)	O7—Si3—O8	102.9 (2)
O5^viii—Y1—O4^iii	94.15 (15)	O12—Si4—O11	112.3 (3)
O9^vi—Y1—O4^iii	86.95 (15)	O12—Si4—O10	114.1 (2)
O9^iii—Y1—O4^iii	93.05 (15)	O11—Si4—O10	106.7 (3)
O4^vi—Y1—O4^iii	180.0000 (10)	O12—Si4—O8	113.3 (2)
O14^ix—Y2—O13^vii	162.32 (14)	O11—Si4—O8	105.2 (2)
O14^ix—Y2—O12^vii	90.23 (16)	O10—Si4—O8	104.5 (2)
O13^vii—Y2—O12^vii	100.81 (16)	O13—Si5—O14	113.5 (2)
O14^ix—Y2—O16^vii	84.41 (16)	O13—Si5—O10^iii	107.8 (2)
O13^vii—Y2—O16^vii	83.37 (16)	O14—Si5—O10^iii	110.8 (2)
O12^vii—Y2—O16^vii	82.65 (15)	O13—Si5—O15	110.3 (2)
O14^ix—Y2—O1^x	103.85 (16)	O14—Si5—O15	109.2 (2)
O13^vii—Y2—O1^x	90.94 (16)	O10^iii—Si5—O15	104.9 (2)
O12^vii—Y2—O1^x	85.09 (15)	O16—Si6—O11^i	111.4 (3)
O16^vii—Y2—O1^x	165.26 (15)	O16—Si6—O6^xi	114.0 (2)
O14^ix—Y2—O1	84.94 (16)	O11^i—Si6—O6^xi	107.7 (2)
O13^vii—Y2—O1	90.07 (16)	O16—Si6—O15	111.7 (2)
O12^vii—Y2—O1	156.35 (15)	O11^i—Si6—O15	104.5 (2)
O16^vii—Y2—O1	119.73 (14)	O6^xi—Si6—O15	106.9 (2)
O1^x—Y2—O1	73.70 (14)	Si2—O2—Si1	137.7 (3)
O4—Si1—O1	115.9 (2)	Si3^vi—O3—Si1	147.0 (3)
O4—Si1—O3	111.7 (2)	Si6^vii—O6—Si2	137.6 (3)
O1—Si1—O3	108.3 (2)	Si3—O7—Si2	142.8 (3)
O4—Si1—O2	110.8 (2)	Si3—O8—Si4	129.8 (3)
O1—Si1—O2	104.0 (2)	Si4—O10—Si5^xii	134.1 (3)
O3—Si1—O2	105.4 (2)	Si4—O11—Si6^i	177.1 (3)
O5—Si2—O2	114.3 (2)	Si6—O15—Si5	127.5 (3)

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