The diphyllosilicate Rb₂(VO)₂[Si₈O₁₉]

Dirubidium divanadyl phylloocta­silicate, Rb₂(VO)₂[Si₈O₁₉], is the first known anhydrous diphyllosilicate containing V^IV. The structure consists of silicate double layers which are separated by [V₂O₈]^8- dimers and is related to that of the compounds A₂Cu₂[Si₈O₁₉] (A = Rb or Cs), although the title compound crystallizes in a noncentrosymmetric ortho­rhom­bic space group. The silicate double layers contain four tetra­hedrally coordinated Si sites in general positions and 12 O sites, nine in general positions and the other three on mirror planes. The vanadyl dimers have two square-pyramidally coordinated V sites (site symmetry m). There are two different 10- and 12-fold coordinated Rb sites with site symmetry m, one of which is a split position located between the dimers in the inter­layer space, while the other is in a channel within the silicate layer.

S1. Comment

Low-dimensional V^IV and mixed-valent V^IV,V compounds are of great interest because of their peculiar magnetic properties, as evidenced by the two-dimensional spin-gap compound CaV₄O₉ (Taniguchi et al., 1995) or the Spin–Peierls system α-NaV₂O₅ (Smolinski et al., 1998). Among the few known silicates containing V^IV, Li₂(VO)SiO₄ has been considered an ideal example of a frustrated two-dimensional square-lattice antiferromagnet (Millet & Satto, 1998). Likewise, few anhydrous double-layer silicates have been reported, among them the Cu^II-bearing compounds of general formula A₂Cu₂[Si₈O₁₉] (A = Rb, Cs) (Heinrich & Gramlich, 1982; Watanabe & Kawahara, 1993). These two isomorphous compounds crystallize in the space group P2₁/m. The staggered silicate double layers consist of corner-sharing SiO₄ tetrahedra, with (Cu₂O₆)^8- dimers (formed by two tetrahedrally distorted square-planar edge-sharing CuO₄ units) interleaved between adjacent double layers.

The title vanadyl compound, (I) (Figs. 1–3), is related to the copper phases but differs in certain key respects. Firstly, it crystallizes in the noncentrosymmetric space group Pmc2₁, and secondly, the silicate double layers of the vanadyl compound are linked differently from those in the copper compounds. In both structures, each single sheet can be described in terms of rings of six corner-sharing SiO₄ tetrahedra which link adjacent single sheets into a double layer (Figs. 1 and 3). Two crystallographically distinct silicate rings can be distinguished in the title compound. In the first kind of silicate ring, five of the six SiO₄ tetrahedra are bonded to neighbouring SiO₄ tetrahedra in the bc plane; only the Si4O₄ tetrahedra of adjacent silicate layers share corners and link the sheets into a double layer. In the second kind of silicate ring, there are two Si4O₄ tetrahedra per ring that link adjacent silicate sheets. In the copper compounds, in contrast, there is only one type of six-membered ring, with two linking SiO₄ tetrahedra in neighbouring positions.

In the title compound, [V₂O₈]^8- dimers of edge-sharing VO₅ pyramids, replacing the (Cu₂O₆)^8- dimers, link adjacent silicate double layers (Fig. 1). The two independent V atoms occupy special positions of site symmetry m. The square-pyramidal oxygen coordination, with one short vanadyl bond and four basal V—O bonds that are almost equal in length, is typical of V^IV (Schindler et al., 2000). The pyramidal bases are inclined with respect to each other around the common O5—O5ⁱⁱ edge [symmetry code: (ii) -x, y, z]; the apices show a syn-orthogonal arrangement (Plass, 1996), i.e. they both point to the same side of the dimeric unit, which has rarely been observed in other substances (Fig. 2). The V1—O12ⁱ and V2—O12ⁱ distances [symmetry code: (i) -x, -y + 1, z - 1/2] between the apical O atom of the (V2)O₅ pyramid and its next V1 and V2 neighbours along c are longer than the value of 2.6 Å which is usually considered the upper limit for a valid V—O distance of the trans bonds in the [1 + 4+1] coordination (Schindler et al., 2000). Therefore, the V coordination is discussed in terms of VO₅ pyramids sharing edges rather than distorted VO₆ octahedra sharing faces.

The disordered Rb1/Rb1' ions are located in between the dimers in channels parallel to c, while the Rb2 ions are enclosed within the double layers. In a projection onto the bc plane, they can be seen to occupy the channels formed by the six-tetrahedron silicate rings parallel to a in a zigzag manner (Fig. 3). Rb1/Rb1' are partially disordered sites that are tenfold coordinated by O, with Rb—O distances ranging from 2.849 (4) to 3.585 (4) Å and from 2.837 (7) to 3.366 (6) Å, respectively. The Rb2 site is 12-fold coordinated by O (distorted hexagonal prism), with Rb—O distances in the range 3.087 (3)–3.352 (3) Å.

Related literature

For related literature, see: Heinrich & Gramlich (1982); Millet & Satto (1998); Plass (1996); Schindler et al. (2000); Smolinski et al. (1998); Taniguchi et al. (1995); Watanabe & Kawahara (1993).

S2. Experimental

RbVO₃ was prepared by the decomposition of stoichiometric amounts of Rb₂CO₃ in the presence of V₂O₅ in air. The resulting single-phased RbVO₃ powder and V₂O₃ were mixed in the molar proportion 2:1 and an excess quantity of SiO₂ was added. The mixture was sealed in an evacuated SiO₂ glass ampoule and heated in a furnace at 1123 K for 5 d, followed by subsequent furnace cooling. From the dark-grey powder obtained, blue to green plate-shaped crystals were isolated, which were then analysed by single-crystal X-ray diffraction on a Stoe IPDS II image-plate diffractometer.

S3. Refinement

During refinement, high maximal/minimal residual electron densities of circa ±1.5 e Å^-3 were observed. The highest peak was located very close to the Rb1 site. When a split position Rb1' was introduced, expressing the partial disorder of the Rb1 site, the residual electron density was reduced substantially to circa ±0.6 e Å^-3. The sum of the occupancies of the Rb1 and Rb1' sites was restrained to be equal to 1 and they refined to values of 0.809 (4) and 0.191 (4), respectively. The anisotropic displacement parameters of the two sites were restrained to be equal.

Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA (Stoe & Cie, 2002); data reduction: X-RED (Stoe & Cie, 1996); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXS97 (Sheldrick, 2008); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. A view of the Rb2(VO)2[Si8O19] structure in a perspective ab projection. Displacement ellipsoids are drawn at the 50% probability level and the unit cell is indicated by black lines. VO5 square pyramids are dark coloured and SiO4 tetrahedra are light coloured. Note the Rb filled channels along c.
	Fig. 2. A view of the Si and V polyhedra that make up the framework of Rb2(VO)2[Si8O19]. Displacement ellipsoids are drawn at the 50% probability level. The [V2O8]^8- dimer is linked to the Si1O4, Si2O4 and Si3O4 tetrahedra via corner sharing, while the Si4O4 tetrahedra interlink the separate silicate layers of a double layer by sharing atom O10. [Symmetry codes: (ii) -x, y, z; (iii) x, -y + 1, z + 1/2; (iv) x, y + 1, z.]
	Fig. 3. A view of the Rb2(VO)2[Si8O19] structure in perspective bc projection. Displacement ellipsoids are drawn at the 50% probability level and the unit cell is indicated by black lines. VO5 square pyramids are dark coloured and SiO4 tetrahedra are light coloured. Note the zigzag pattern of channels occupied by Rb2 and the empty channels with two linking Si4O4 tetrahedra per six-tetrahedron ring.

Dirubidium divanadyl phyllo-octasilicate

Crystal data

Rb2(VO)2[Si8O19]	F(000) = 800
Mr = 833.54	Dx = 2.800 Mg m^−3
Orthorhombic, Pmc21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: p 2c -2	Cell parameters from 33551 reflections
a = 11.0513 (9) Å	θ = 2.7–33.5°
b = 10.2765 (6) Å	µ = 6.43 mm^−1
c = 8.7052 (6) Å	T = 301 K
V = 988.64 (12) Å^3	Plate, green
Z = 2	0.3 × 0.2 × 0.08 mm

Data collection

Stoe IPDS II diffractometer	4022 independent reflections
Radiation source: fine-focus sealed tube	3669 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.069
Detector resolution: 0 pixels mm^-1	θmax = 33.5°, θmin = 2.7°
Rotation method scans	h = −17→17
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1996)	k = −15→15
Tmin = 0.251, Tmax = 0.649	l = −13→13
37398 measured reflections

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	w = 1/[σ^2(Fo^2) + (0.0175P)^2 + 2.137P] where P = (Fo^2 + 2Fc^2)/3
R[F^2 > 2σ(F^2)] = 0.033	(Δ/σ)max < 0.001
wR(F^2) = 0.065	Δρmax = 0.61 e Å^−3
S = 1.10	Δρmin = −0.64 e Å^−3
4022 reflections	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
165 parameters	Extinction coefficient: 0.0039 (4)
2 restraints	Absolute structure: Flack (1983), with how many Friedel pairs?
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.004 (6)

Special details

Experimental. n

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'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 > σ(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	Occ. (<1)
Rb1	0.0000	0.88996 (13)	0.43786 (13)	0.0240 (2)	0.809 (4)
Rb1'	0.0000	0.8930 (7)	0.3970 (6)	0.0240 (2)	0.191 (4)
Rb2	0.5000	0.39467 (5)	0.16154 (6)	0.02358 (10)
V1	0.0000	0.24109 (7)	0.37703 (9)	0.01270 (12)
V2	0.0000	0.54043 (6)	0.45624 (8)	0.01113 (11)
Si1	0.25795 (7)	0.13292 (8)	0.28905 (9)	0.01054 (14)
Si2	0.25695 (7)	0.37945 (7)	0.46804 (9)	0.01041 (13)
Si3	0.26184 (7)	0.63946 (7)	0.32673 (9)	0.01053 (14)
Si4	0.36339 (6)	0.89959 (7)	0.46157 (9)	0.00983 (12)
O1	0.26916 (19)	0.0020 (3)	0.3936 (3)	0.0219 (4)
O2	0.3469 (2)	0.1134 (3)	0.1440 (3)	0.0278 (5)
O3	0.1210 (2)	0.1585 (2)	0.2466 (3)	0.0164 (4)
O4	0.31694 (19)	0.2555 (2)	0.3824 (3)	0.0185 (4)
O5	0.11425 (17)	0.3881 (2)	0.4333 (2)	0.0135 (4)
O6	0.32496 (19)	0.5090 (2)	0.4027 (3)	0.0189 (4)
O7	0.2912 (2)	0.6268 (3)	0.1457 (3)	0.0280 (5)
O8	0.1235 (2)	0.6522 (2)	0.3685 (3)	0.0178 (4)
O9	0.3443 (2)	0.7580 (3)	0.3896 (4)	0.0268 (5)
O10	0.5000	0.9458 (3)	0.4280 (3)	0.0128 (5)
O11	0.0000	0.1560 (4)	0.5296 (4)	0.0270 (8)
O12	0.0000	0.5741 (4)	0.6351 (4)	0.0231 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Rb1	0.0206 (2)	0.0151 (2)	0.0362 (6)	0.000	0.000	−0.0038 (5)
Rb1'	0.0206 (2)	0.0151 (2)	0.0362 (6)	0.000	0.000	−0.0038 (5)
Rb2	0.01929 (19)	0.0287 (2)	0.0227 (2)	0.000	0.000	−0.0027 (2)
V1	0.0097 (3)	0.0096 (3)	0.0188 (3)	0.000	0.000	−0.0014 (2)
V2	0.0086 (2)	0.0103 (2)	0.0146 (3)	0.000	0.000	−0.0014 (2)
Si1	0.0090 (3)	0.0112 (3)	0.0115 (3)	0.0021 (2)	0.0000 (2)	−0.0005 (3)
Si2	0.0090 (3)	0.0110 (3)	0.0112 (3)	0.0003 (2)	−0.0001 (3)	−0.0002 (3)
Si3	0.0102 (3)	0.0093 (3)	0.0122 (3)	−0.0011 (2)	0.0002 (3)	−0.0004 (3)
Si4	0.0084 (3)	0.0089 (3)	0.0122 (3)	−0.0004 (2)	−0.0001 (2)	0.0007 (3)
O1	0.0115 (9)	0.0167 (9)	0.0376 (12)	0.0023 (9)	−0.0006 (9)	0.0111 (9)
O2	0.0178 (10)	0.0498 (16)	0.0159 (10)	0.0058 (11)	0.0043 (9)	−0.0057 (11)
O3	0.0121 (9)	0.0164 (10)	0.0206 (10)	0.0039 (8)	−0.0025 (8)	−0.0042 (8)
O4	0.0103 (8)	0.0161 (9)	0.0290 (10)	0.0015 (8)	−0.0005 (9)	−0.0071 (8)
O5	0.0087 (8)	0.0124 (8)	0.0194 (10)	−0.0004 (7)	−0.0017 (7)	−0.0020 (7)
O6	0.0122 (9)	0.0131 (9)	0.0313 (11)	−0.0026 (8)	−0.0011 (9)	0.0072 (8)
O7	0.0212 (10)	0.0512 (16)	0.0117 (9)	−0.0030 (11)	−0.0005 (9)	−0.0023 (11)
O8	0.0125 (9)	0.0133 (9)	0.0276 (11)	−0.0001 (7)	0.0044 (8)	0.0026 (8)
O9	0.0206 (11)	0.0145 (10)	0.0454 (15)	−0.0046 (9)	−0.0018 (11)	−0.0104 (10)
O10	0.0097 (11)	0.0137 (12)	0.0149 (13)	0.000	0.000	0.0015 (10)
O11	0.035 (2)	0.0209 (17)	0.0247 (17)	0.000	0.000	0.0017 (14)
O12	0.0210 (15)	0.0271 (17)	0.0214 (17)	0.000	0.000	−0.0051 (13)

Geometric parameters (Å, º)

Rb1—O11^i	2.849 (4)	V1—Rb2^x	7.1188 (7)
Rb1—O8^ii	2.863 (3)	V1—Rb2^iv	7.1188 (7)
Rb1—O8	2.863 (3)	V2—O12	1.595 (4)
Rb1—O3^iii	3.043 (3)	V2—O8	1.941 (2)
Rb1—O3^iv	3.043 (3)	V2—O8^ii	1.941 (2)
Rb1—O1^i	3.213 (2)	V2—O5^ii	2.021 (2)
Rb1—O1^v	3.213 (2)	V2—O5	2.021 (2)
Rb1—O3^v	3.489 (3)	V2—O12^vi	3.033 (4)
Rb1—O3^i	3.489 (3)	V2—Si3	3.2680 (9)
Rb1—O11^vi	3.585 (4)	V2—Si3^ii	3.2680 (9)
Rb1—V2	3.5954 (15)	V2—Si2^ii	3.2880 (8)
Rb1—V1^i	3.6471 (15)	V2—Si2	3.2880 (8)
Rb1'—O8^ii	2.837 (7)	V2—O6	3.636 (2)
Rb1'—O8	2.837 (7)	V2—O6^ii	3.636 (2)
Rb1'—O11^i	2.939 (8)	V2—O11	4.002 (4)
Rb1'—O1^i	3.179 (3)	V2—O7^iv	4.004 (3)
Rb1'—O1^v	3.179 (3)	V2—O7^iii	4.004 (3)
Rb1'—O11^vi	3.238 (7)	V2—O3^iii	4.213 (2)
Rb1'—O3^i	3.308 (7)	V2—O3^iv	4.213 (2)
Rb1'—O3^v	3.308 (7)	V2—O7^ii	4.295 (3)
Rb1'—O3^iii	3.366 (6)	V2—O7	4.295 (3)
Rb1'—O3^iv	3.366 (6)	V2—V1^iv	4.2964 (10)
Rb1'—V1^i	3.581 (7)	V2—O8^iii	4.320 (3)
Rb1'—V2	3.660 (7)	V2—O8^iv	4.320 (3)
Rb2—O6^vii	3.087 (3)	V2—V2^vi	4.4312 (10)
Rb2—O6	3.087 (3)	V2—V2^iv	4.4312 (10)
Rb2—O6^viii	3.130 (2)	V2—Si3^iii	4.7109 (10)
Rb2—O6^ix	3.130 (2)	V2—Si3^iv	4.7109 (10)
Rb2—O4^vii	3.136 (3)	V2—V1^vi	5.5194 (10)
Rb2—O4	3.136 (3)	V2—Rb2^x	5.8457 (5)
Rb2—O9^viii	3.321 (3)	V2—Rb2^iv	5.8457 (5)
Rb2—O9^ix	3.321 (3)	V2—Rb1'^iv	5.879 (6)
Rb2—O7^vii	3.322 (3)	V2—Rb1^iv	6.0942 (15)
Rb2—O7	3.322 (3)	V2—Rb2^xii	6.2736 (6)
Rb2—O2	3.352 (3)	V2—Rb2^xv	8.3949 (8)
Rb2—O2^vii	3.352 (3)	V2—Rb2^xvi	8.3949 (8)
Rb2—Si2^vii	3.7892 (9)	Si1—O3	1.580 (2)
Rb2—Si2	3.7892 (9)	Si1—O2	1.613 (3)
Rb2—Si4^viii	3.8018 (9)	Si1—O1	1.629 (3)
Rb2—Si4^ix	3.8018 (9)	Si1—O4	1.635 (2)
Rb2—Si3^vii	3.9145 (9)	Si1—Rb1'^xi	3.884 (5)
Rb2—Si3	3.9145 (9)	Si1—Rb1^xi	4.0049 (13)
Rb2—Si2^ix	3.9294 (9)	Si1—Rb2^x	6.4217 (10)
Rb2—Si2^viii	3.9294 (9)	Si2—O7^iii	1.594 (3)
Rb2—Si3^viii	3.9428 (9)	Si2—O5	1.608 (2)
Rb2—Si3^ix	3.9428 (9)	Si2—O4	1.618 (2)
Rb2—Si1	3.9525 (9)	Si2—O6	1.631 (2)
Rb2—Si1^vii	3.9525 (9)	Si2—Rb2^x	3.9294 (9)
Rb2—O10^ix	4.047 (3)	Si2—Rb2^xv	6.6095 (10)
Rb2—O9^vii	4.565 (3)	Si3—O8	1.577 (2)
Rb2—O9	4.565 (3)	Si3—O7	1.614 (3)
Rb2—O4^ix	4.788 (2)	Si3—O9	1.617 (3)
Rb2—O4^viii	4.788 (2)	Si3—O6	1.649 (2)
Rb2—O7^x	4.810 (3)	Si3—Rb2^x	3.9428 (9)
Rb2—O7^iii	4.810 (3)	Si3—V2^vi	4.7109 (10)
Rb2—Rb2^x	4.8613 (5)	Si3—Rb2^ix	6.3704 (10)
Rb2—Rb2^ix	4.8613 (5)	Si4—O1^i	1.595 (2)
Rb2—O5^vii	4.876 (2)	Si4—O9	1.598 (3)
Rb2—O5	4.876 (2)	Si4—O2^iii	1.604 (3)
Rb2—O3	4.897 (2)	Si4—O10	1.6093 (13)
Rb2—O3^vii	4.897 (2)	Si4—Rb2^x	3.8018 (9)
Rb2—O8^viii	4.904 (2)	Si4—Rb2^i	5.9148 (9)
Rb2—O8^ix	4.904 (2)	O1—Si4^xi	1.595 (2)
Rb2—O7^viii	5.053 (3)	O1—Rb1'^xi	3.179 (3)
V1—O11	1.590 (4)	O1—Rb1^xi	3.213 (2)
V1—O3^ii	1.949 (2)	O1—Rb2^xvii	5.345 (2)
V1—O3	1.949 (2)	O2—Si4^viii	1.604 (3)
V1—O5	2.029 (2)	O3—Rb1^vi	3.043 (3)
V1—O5^ii	2.029 (2)	O3—Rb1'^xi	3.308 (7)
V1—O12^vi	2.836 (4)	O3—Rb1'^vi	3.366 (6)
V1—V2	3.1525 (9)	O3—Rb1^xi	3.489 (3)
V1—Si1^ii	3.1542 (9)	O3—V2^vi	4.213 (2)
V1—Si1	3.1542 (9)	O4—Rb2^x	4.788 (2)
V1—Si2	3.2731 (9)	O5—Rb2^x	5.206 (2)
V1—Si2^ii	3.2731 (9)	O6—Rb2^x	3.130 (2)
V1—O4^ii	3.506 (2)	O7—Si2^viii	1.594 (3)
V1—O4	3.506 (2)	O7—V2^vi	4.004 (3)
V1—Rb1'^xi	3.581 (7)	O7—V1^vi	4.204 (3)
V1—Rb1^xi	3.6471 (15)	O7—Rb2^ix	4.810 (3)
V1—O1^ii	3.861 (2)	O7—Rb2^x	5.053 (3)
V1—O1	3.861 (2)	O8—V2^vi	4.320 (3)
V1—Rb1^vi	4.0533 (15)	O8—Rb2^x	4.904 (2)
V1—O12	4.093 (4)	O9—Rb2^x	3.321 (3)
V1—O7^iii	4.204 (3)	O10—Si4^vii	1.6093 (13)
V1—O7^iv	4.204 (3)	O10—Rb2^x	4.047 (3)
V1—V2^vi	4.2964 (10)	O10—Rb2^i	5.163 (3)
V1—Rb1'^vi	4.400 (6)	O11—Rb1^xi	2.849 (4)
V1—Rb1'^iv	4.732 (6)	O11—Rb1'^xi	2.939 (8)
V1—Rb1^iv	5.0645 (15)	O11—Rb1'^iv	3.238 (7)
V1—V2^iv	5.5194 (10)	O11—Rb1^iv	3.585 (4)
V1—Rb2^xii	6.0450 (6)	O12—V1^iv	2.836 (4)
V1—V1^xiii	6.5954 (11)	O12—V2^iv	3.033 (4)
V1—V1^xiv	6.5954 (11)	O12—Rb2^x	5.5398 (5)
V1—V1^iv	6.8747 (12)	O12—Rb2^iv	5.5398 (5)
V1—V1^vi	6.8747 (12)
O11—V1—O3^ii	104.31 (13)	O5^ii—V2—O7^iii	102.15 (7)
O11—V1—O3	104.31 (13)	O5—V2—O7^iii	37.46 (7)
O3^ii—V1—O3	86.65 (13)	O12^vi—V2—O7^iii	102.31 (6)
O11—V1—O5	101.99 (13)	O6—V2—O7^iii	38.81 (5)
O3^ii—V1—O5	153.12 (10)	O6^ii—V2—O7^iii	143.96 (6)
O3—V1—O5	92.17 (9)	O11—V2—O7^iii	60.69 (5)
O11—V1—O5^ii	101.99 (13)	O7^iv—V2—O7^iii	106.98 (8)
O3^ii—V1—O5^ii	92.17 (9)	O12—V2—O3^iii	41.86 (13)
O3—V1—O5^ii	153.12 (10)	O8—V2—O3^iii	65.05 (8)
O5—V1—O5^ii	76.97 (12)	O8^ii—V2—O3^iii	91.41 (8)
O11—V1—O12^vi	171.29 (16)	O5^ii—V2—O3^iii	145.74 (7)
O3^ii—V1—O12^vi	81.91 (9)	O5—V2—O3^iii	115.46 (7)
O3—V1—O12^vi	81.91 (9)	O12^vi—V2—O3^iii	146.92 (7)
O5—V1—O12^vi	71.36 (9)	O6—V2—O3^iii	80.13 (5)
O5^ii—V1—O12^vi	71.36 (9)	O6^ii—V2—O3^iii	117.10 (5)
O11—V1—O4^ii	90.69 (5)	O11—V2—O3^iii	128.99 (6)
O3^ii—V1—O4^ii	48.75 (8)	O7^iv—V2—O3^iii	108.85 (5)
O3—V1—O4^ii	135.37 (8)	O7^iii—V2—O3^iii	79.22 (5)
O5—V1—O4^ii	125.95 (7)	O12—V2—O3^iv	41.86 (13)
O5^ii—V1—O4^ii	48.98 (7)	O8—V2—O3^iv	91.41 (8)
O12^vi—V1—O4^ii	88.94 (5)	O8^ii—V2—O3^iv	65.05 (8)
O11—V1—O4	90.69 (5)	O5^ii—V2—O3^iv	115.46 (7)
O3^ii—V1—O4	135.37 (8)	O5—V2—O3^iv	145.74 (7)
O3—V1—O4	48.75 (8)	O12^vi—V2—O3^iv	146.92 (7)
O5—V1—O4	48.98 (7)	O6—V2—O3^iv	117.10 (5)
O5^ii—V1—O4	125.95 (7)	O6^ii—V2—O3^iv	80.13 (5)
O12^vi—V1—O4	88.94 (5)	O11—V2—O3^iv	128.99 (6)
O4^ii—V1—O4	174.92 (8)	O7^iv—V2—O3^iv	79.22 (5)
O11—V1—O1^ii	67.61 (9)	O7^iii—V2—O3^iv	108.85 (5)
O3^ii—V1—O1^ii	38.36 (8)	O3^iii—V2—O3^iv	37.01 (6)
O3—V1—O1^ii	105.86 (8)	O12—V2—O7^ii	124.72 (7)
O5—V1—O1^ii	160.80 (8)	O8—V2—O7^ii	99.03 (9)
O5^ii—V1—O1^ii	89.16 (7)	O8^ii—V2—O7^ii	26.25 (8)
O12^vi—V1—O1^ii	117.00 (6)	O5^ii—V2—O7^ii	68.27 (7)
O4^ii—V1—O1^ii	41.98 (5)	O5—V2—O7^ii	124.46 (7)
O4—V1—O1^ii	142.76 (6)	O12^vi—V2—O7^ii	60.01 (5)
O11—V1—O1	67.61 (9)	O6—V2—O7^ii	132.66 (6)
O3^ii—V1—O1	105.86 (8)	O6^ii—V2—O7^ii	36.64 (5)
O3—V1—O1	38.36 (8)	O11—V2—O7^ii	107.72 (6)
O5—V1—O1	89.16 (7)	O7^iv—V2—O7^ii	75.27 (5)
O5^ii—V1—O1	160.80 (8)	O7^iii—V2—O7^ii	161.83 (5)
O12^vi—V1—O1	117.00 (6)	O3^iii—V2—O7^ii	117.62 (5)
O4^ii—V1—O1	142.76 (6)	O3^iv—V2—O7^ii	89.32 (5)
O4—V1—O1	41.98 (5)	O12—V2—O7	124.72 (7)
O1^ii—V1—O1	100.80 (8)	O8—V2—O7	26.25 (8)
O11—V1—O12	90.05 (15)	O8^ii—V2—O7	99.03 (9)
O3^ii—V1—O12	133.15 (7)	O5^ii—V2—O7	124.46 (7)
O3—V1—O12	133.15 (7)	O5—V2—O7	68.27 (7)
O5—V1—O12	40.99 (6)	O12^vi—V2—O7	60.01 (5)
O5^ii—V1—O12	40.99 (6)	O6—V2—O7	36.64 (5)
O12^vi—V1—O12	81.24 (3)	O6^ii—V2—O7	132.66 (6)
V2—V1—O12	20.65 (5)	O11—V2—O7	107.72 (6)
O4^ii—V1—O12	87.56 (4)	O7^iv—V2—O7	161.83 (5)
O4—V1—O12	87.56 (4)	O7^iii—V2—O7	75.27 (5)
O1^ii—V1—O12	120.76 (5)	O3^iii—V2—O7	89.32 (5)
O1—V1—O12	120.76 (5)	O3^iv—V2—O7	117.62 (5)
O11—V1—O7^iii	73.30 (9)	O7^ii—V2—O7	97.04 (7)
O3^ii—V1—O7^iii	171.96 (8)	O12—V2—O8^iii	44.63 (13)
O3—V1—O7^iii	86.54 (7)	O8—V2—O8^iii	112.08 (10)
O5—V1—O7^iii	31.66 (7)	O8^ii—V2—O8^iii	145.13 (9)
O5^ii—V1—O7^iii	95.84 (7)	O5^ii—V2—O8^iii	85.68 (7)
O12^vi—V1—O7^iii	101.35 (6)	O5—V2—O8^iii	61.96 (7)
O4^ii—V1—O7^iii	138.05 (6)	O12^vi—V2—O8^iii	126.01 (7)
O4—V1—O7^iii	38.20 (5)	O6—V2—O8^iii	75.74 (5)
O1^ii—V1—O7^iii	140.77 (6)	O6^ii—V2—O8^iii	112.21 (5)
O1—V1—O7^iii	66.10 (6)	O11—V2—O8^iii	54.19 (6)
O12—V1—O7^iii	54.87 (4)	O7^iv—V2—O8^iii	73.44 (5)
O11—V1—O7^iv	73.30 (9)	O7^iii—V2—O8^iii	37.54 (5)
O3^ii—V1—O7^iv	86.54 (7)	O3^iii—V2—O8^iii	74.80 (4)
O3—V1—O7^iv	171.96 (8)	O3^iv—V2—O8^iii	86.47 (4)
O5—V1—O7^iv	95.84 (7)	O7^ii—V2—O8^iii	148.67 (5)
O5^ii—V1—O7^iv	31.66 (7)	O7—V2—O8^iii	112.38 (5)
O12^vi—V1—O7^iv	101.35 (6)	V1^iv—V2—O8^iii	62.05 (3)
O4^ii—V1—O7^iv	38.20 (5)	O12—V2—O8^iv	44.63 (13)
O4—V1—O7^iv	138.05 (6)	O8—V2—O8^iv	145.13 (9)
O1^ii—V1—O7^iv	66.10 (6)	O8^ii—V2—O8^iv	112.08 (10)
O1—V1—O7^iv	140.77 (6)	O5^ii—V2—O8^iv	61.96 (7)
O12—V1—O7^iv	54.87 (4)	O5—V2—O8^iv	85.68 (7)
O7^iii—V1—O7^iv	99.91 (7)	O12^vi—V2—O8^iv	126.01 (7)
O12—V2—O8	104.83 (12)	V1—V2—O8^iv	74.60 (3)
O12—V2—O8^ii	104.83 (12)	O6—V2—O8^iv	112.21 (5)
O8—V2—O8^ii	89.39 (14)	O6^ii—V2—O8^iv	75.74 (5)
O12—V2—O5^ii	105.33 (12)	O11—V2—O8^iv	54.19 (6)
O8—V2—O5^ii	149.20 (11)	O7^iv—V2—O8^iv	37.54 (5)
O8^ii—V2—O5^ii	88.86 (9)	O7^iii—V2—O8^iv	73.44 (5)
O12—V2—O5	105.33 (12)	O3^iii—V2—O8^iv	86.47 (4)
O8—V2—O5	88.86 (8)	O3^iv—V2—O8^iv	74.80 (4)
O8^ii—V2—O5	149.20 (11)	O7^ii—V2—O8^iv	112.38 (5)
O5^ii—V2—O5	77.33 (12)	O7—V2—O8^iv	148.67 (5)
O12—V2—O12^vi	169.69 (10)	V1^iv—V2—O8^iv	62.05 (3)
O8—V2—O12^vi	82.35 (9)	O8^iii—V2—O8^iv	36.84 (6)
O8^ii—V2—O12^vi	82.35 (9)	O3—Si1—O2	114.93 (14)
O5^ii—V2—O12^vi	66.94 (8)	O3—Si1—O1	109.92 (13)
O5—V2—O12^vi	66.94 (8)	O2—Si1—O1	106.77 (15)
O12—V2—O6	98.30 (4)	O3—Si1—O4	111.72 (12)
O8—V2—O6	46.16 (8)	O2—Si1—O4	104.00 (14)
O8^ii—V2—O6	134.17 (8)	O1—Si1—O4	109.17 (15)
O5^ii—V2—O6	122.39 (7)	O7^iii—Si2—O5	114.69 (12)
O5—V2—O6	45.69 (7)	O7^iii—Si2—O4	108.56 (15)
O12^vi—V2—O6	81.22 (4)	O5—Si2—O4	111.01 (12)
O12—V2—O6^ii	98.30 (4)	O7^iii—Si2—O6	105.18 (14)
O8—V2—O6^ii	134.17 (8)	O5—Si2—O6	109.93 (12)
O8^ii—V2—O6^ii	46.16 (8)	O4—Si2—O6	107.05 (13)
O5^ii—V2—O6^ii	45.69 (7)	O8—Si3—O7	115.26 (14)
O5—V2—O6^ii	122.39 (7)	O8—Si3—O9	113.93 (14)
O12^vi—V2—O6^ii	81.22 (4)	O7—Si3—O9	106.13 (15)
O6—V2—O6^ii	162.06 (9)	O8—Si3—O6	112.66 (12)
O12—V2—O11	93.32 (15)	O7—Si3—O6	103.94 (15)
O8—V2—O11	130.33 (7)	O9—Si3—O6	103.78 (14)
O8^ii—V2—O11	130.33 (7)	O1^i—Si4—O9	111.66 (15)
O5^ii—V2—O11	41.51 (6)	O1^i—Si4—O2^iii	110.38 (15)
O5—V2—O11	41.51 (6)	O9—Si4—O2^iii	107.30 (16)
O12^vi—V2—O11	76.36 (9)	O1^i—Si4—O10	110.52 (14)
O6—V2—O11	86.15 (4)	O9—Si4—O10	108.74 (15)
O6^ii—V2—O11	86.15 (4)	O2^iii—Si4—O10	108.11 (14)
O12—V2—O7^iv	71.99 (8)	V1—O3—V2^vi	79.15 (7)
O8—V2—O7^iv	168.97 (8)	V2—O5—V1	102.23 (9)
O8^ii—V2—O7^iv	81.42 (8)	V2^vi—O7—V1^vi	45.09 (3)
O5^ii—V2—O7^iv	37.46 (7)	V2^vi—O7—V2	64.43 (4)
O5—V2—O7^iv	102.15 (8)	V1^vi—O7—V2	80.99 (4)
O12^vi—V2—O7^iv	102.31 (6)	V2—O8—V2^vi	80.41 (8)
O6—V2—O7^iv	143.96 (6)	V1—O11—V2	47.47 (11)
O6^ii—V2—O7^iv	38.81 (5)	V2—O12—V1^iv	150.5 (2)
O11—V2—O7^iv	60.69 (5)	V2—O12—V2^iv	144.7 (2)
O12—V2—O7^iii	71.99 (8)	V1^iv—O12—V2^iv	64.87 (8)
O8—V2—O7^iii	81.42 (8)	V1^iv—O12—V1	165.34 (13)
O8^ii—V2—O7^iii	168.97 (8)	V2^iv—O12—V1	100.46 (10)

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