Sr3Al10SiO20 from single crystal data

inorganic papers

Acta Cryst.(2007). E63, i19–i21 doi:10.1107/S1600536806054936 Rief and Kubel _Sr

3Al10SiO20

i19

Acta Crystallographica Section E

Structure Reports

Online

ISSN 1600-5368

Sr

Al

SiO

from single-crystal data

Andreas Rief* and Frank Kubel

Vienna University of Technology, Institute for Chemical Technologies and Analytics, Getreidemarkt 9/164-SC, Vienna A-1160, Austria

Correspondence e-mail: [email protected]

Key indicators

Single-crystal X-ray study

T= 298 K

Mean(Al–O) = 0.002 A˚ Disorder in main residue

Rfactor = 0.036

wRfactor = 0.032

Data-to-parameter ratio = 11.9

For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.

Received 15 November 2006 Accepted 18 December 2006

#2007 International Union of Crystallography All rights reserved

Single crystals of tristrontium decaaluminum silicon icosa-oxide were synthesized by local flux growth with H3BO3as mineralizer. Lattice parameters and refinement data indicate no significant incorporation of B in the structure. Pairs of AlO6octahedra are located between layers of edge-linked Al/ Si–O4 tetrahedra. The Sr1 (2/msymmetry) and Sr2 (mirror plane) sites are orientated in layers perpendicular to the layers of Al/Si–O polyhedra.

Comment

Recently, Sr3Al10SiO20 doped with Tb, Eu or Eu/Ho was discovered to be a blue-emitting long-lasting phosphor for optical applications, such as TFT screens and LEDs (Kuanget al. 2005, 2006;Kubota & Shimada, 2002; Kubotaet al., 2002). Sr3Al10SiO20is isostructural with Pb3Al10GeO20(monoclinic,

C2/m; Vinek et al., 1970). The first structure refinement of Sr3Al10SiO20 was performed by Kubota et al. (2001) using powder diffraction data by Rietveld refinement based on Pb3Al10GeO20by replacing Pb sites with Sr. In order to obtain a more precise structure determination, we synthesized single crystals of Sr3Al10SiO20 (SR3). The published results from powder data agree very well with our single-crystal

measure-Figure 1

ments. The lattice parameters of the single crystal (seeCrystal data) agree with the literature [a = 15.1416 (18), b = 11.1843 (12), c = 4.9026 (13) A˚ , = 108.117 (5) _{and V =}

789.06 (16) A˚3; Kubota et al. 2001]. Capron et al. (2002) puplished a powder diffraction study with a refinement in space group I2/m [a = 14.394 (2), b = 11.189 (2), c = 4.904 (1) A˚ ,= 90.793 (1),V= 789.74 A˚3]. The refinement of the structure model against single-crystal data was performed usingXtal3.2 (Hallet al., 1992) to a finalR= 0.036. The good correlation between the powder and single-crystal data excludes any incorporation of B, even in small amounts. B tends to replace the tetravalent or octahedral Al position, and at least a reduction of the unit cell in thea-axis direction (due to deformations of the octahedral chains in this direction) should be observed.

A detailed description of the structure was reported by Kubotaet al.(2001). The matrix is composed of corner-linked Al/Si tetrahedra arranged in layers along thecaxis, connected to isolated pairs of edge-linked Al octahedra (see Fig. 1). These octahedra show distortion in all bond lengths and angles. Selected bond distances are given in Table 1. The averaged Al/Si—O bond distances are almost the same for both tetrahedral Al/Si positions [Al1/Si1—O 1.745 (6), Al2/ Si2—O 1.737 (6) A˚ ] and an identical substitution ratio is assumed. The occupancy factor for Si1,2 refined to 0.125 (subsequently set at this value) and is the same as is given in the literature. In the original Pb3Al10GeO20compound, all Al sites were substituted by a small amount (s.o.f. 0.091) of Ge.

Remarkable in this structure is the short distance between Sr1 and O5 of only 2.392 (3) A˚ ; the sum of ionic radii for Sr2+ and O2–is 2.58 A˚ (Shannon, 1976). Capronet al.(2002) report an even shorter Sr—O distance of 2.388 (8) A˚ . For Sr1, CN 12 and for Sr2, CN (4 + 4 + 4) is observed. The other Sr—O distances (Table 2) are within or longer than the range expected from the atomic radii [Sr(x)—O(y) > 2.68 A˚ ].

Experimental

Single crystals were synthesized from well ground analytical SrCO3, Al(OH)3(both Merck) and SiO2(Fluka) by adding 10% by weight of H3BO3(Aldrich). The carefully homogenized mixture of educts was pressed into pellets and fired at 1723 K (180 K h1) in a corundum crucible for 24 h. The samples were slowly cooled down to room temperature with a cooling rate of 180 K h1_{. To improve yield and} crystal growth, samples were crushed, refired and repelleted after 12 h of heating. The hard sintered pellets were crushed carefully in a mortar into smaller fragments. Under polarized light, microscopic crystals showing homogeneous extinction were separated and prepared for single-crystal measurements.

Crystal data

Sr3Al10SiO20

Mr= 880.75

Monoclinic,C2=m a= 15.1438 (18) A˚ b= 11.1858 (13) A˚ c= 4.9018 (6) A˚

Z= 2

Dx= 3.707 Mg m

3

MoKradiation

= 10.86 mm1

T= 298 K Splinter, colourless

Data collection

Siemens SMART APEX diffractometer

!scans

Absorption correction: spherical (Tibballs, 1982)

Tmin= 0.302,Tmax= 0.318

4207 measured reflections 1261 independent reflections 1022 reflections withI> 3(I) Rint= 0.033

max= 30.5

Refinement

Refinement onF R[F2_{> 2(F}2_{)] = 0.036}

wR(F2) = 0.032 S= 1.70 1022 reflections

86 parameters (/)max= 0.001

max= 1.66 e A˚

3

min=1.15 e A˚

3

Table 1

Selected bond lengths (A˚ ).

Sr1i—O5i 2.3932 (17) Sr1i —O2i 2.6832 (18) Sr1i —O3ii 2.7018 (15) Sr1i —O4iii 2.8420 (16) Sr1i —O2ii 3.1967 (18) Sr1i —O6i 3.410 (3)

Sr1i—O1i 3.4812 (14) Sr2iv —O6i 2.527 (2) Sr2iv —O3v 2.6781 (16) Sr2iv —O6vi 3.158 (3) Sr2i —O1vii 3.5126 (14)

Symmetry codes: (i)xþ1 2;yþ

1 2;z; (ii)xþ

1 2;yþ

1

2;zþ1; (iii)xþ1;y;zþ1; (iv)

xþ1;y;zþ1; (v) xþ3 2;yþ

1

2;zþ1; (vi) xþ 1 2;yþ

1

2;zþ1; (vii)

xþ1 2;yþ

3 2;z.

The highest peak is located 0.00 A˚ from atom Sr2 and the deepest hole is located 1.02 A˚ from atom O5.

Data collection:SMART(Bruker, 2001); cell refinement:SAINT

(Bruker, 1999); data reduction:Xtal3.2 (Hallet al., 1992); program(s) used to solve structure:Xtal3.2; program(s) used to refine structure:

Xtal3.2; molecular graphics:Xtal3.2; software used to prepare mate-rial for publication:Xtal3.2.

References

Bruker (1999).SAINT(Version 6.02a). Bruker AXS Inc., Madison, Wisconsin, USA.

Figure 2

Coordination environments for Sr1 and Sr2. Symmetry codes: (i)1 2+x, 1

2+y,z; (ii) 1 2+x,

1

2y,z; (iii) 1 2+x,

1

2y, 1 +z; (iv) 1 2+x,

1

2+y, 1 +z; (v)

1x,y, 1z; (vi) 1x, 1y, 1z; (vii)3 2x,

1

2+y, 2z; (viii) 3 2x, 1

2y, 1z; (ix) 3 2x,

1

2+y, 1z; (x) 1 2+x,

3

2y,z; (xi) 1 2x,

3 2y,-z;

(xii) 1 2 x,

1

2 + y,-z. Displacement ellipsoids are drawn at the 50%

Capron, M., Fayon, F., Coutures, J., Massiot, D. & Douy, A. (2002).J. Solid State Chem.169, 53–59.

Hall, S. R., Flack, H. D. & Stewart, J. M. (1992). Editors.Xtal3.2.Universities of Western Australia, Australia, Geneva, Switzerland, and Maryland, USA. Kuang, J. Y., Liu, Y. L. & Zhang, J. X. (2006).J. Mater. Sci.41, 5500–5503. Kuang, J. Y., Liu, Y. L., Zhang, J. X., Huang, L., Rong, J. & Yuan, D. (2005).

Solid State Commun.136, 6–10.

Kubota, S. & Shimada, M. (2002).Appl. Phys. Lett.15, 2749–2751. Kubota, S., Yamane, H. & Shimada, M. (2001).Acta Cryst.E57, i60–i61. Kubota, S., Yamane, H. & Shimada, M. (2002).Chem. Mater.14, 4015–4016. Shannon, R. D. (1976).Acta Cryst.A32, 751–767.

Tibballs, J. E. (1982).Acta Cryst.A38, 161–163.

Vinek, H., Voellenkle, H. & Nowotny, H. (1970).Monatsh. Chem.101, 275– 284.

inorganic papers

Acta Cryst.(2007). E63, i19–i21 Rief and Kubel _Sr

supporting information

Acta Cryst. (2007). E63, i19–i21 [https://doi.org/10.1107/S1600536806054936]

Sr

Al

SiO

from single-crystal data

Andreas Rief and Frank Kubel

tristrontium decaaluminum silicon icosaoxide

Crystal data

Sr3Al10SiO20

Mr = 880.75 Monoclinic, C2/m

Hall symbol: -C 2y

a = 15.1438 (18) Å

b = 11.1858 (13) Å

c = 4.9018 (6) Å

β = 108.137 (2)°

V = 789.09 (16) Å3

Z = 2

F(000) = 836

Dx = 3.707 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 4207 reflections

θ = 2.3–30.5°

µ = 10.86 mm−1

T = 298 K

Splinter, colourless

0.14 × 0.11 × 0.09 × 0.11 (radius) mm

Data collection

Siemens SMART APEX diffractometer

Detector resolution: 512 pixels mm-1

ω scans

Absorption correction: spherical (Tibballs, 1982)

Tmin = 0.302, Tmax = 0.318 4207 measured reflections

1261 independent reflections 1022 reflections with I > 3σ(I)

Rint = 0.033

θmax = 30.5°, θmin = 2.3°

h = −21→21

k = −15→15

l = −6→5

Refinement

Refinement on F

Least-squares matrix: full

R[F2 _{> 2σ(F}2_{)] = 0.036}

wR(F2_{) = 0.032}

S = 1.70 1022 reflections 86 parameters

0 restraints 18 constraints

(Δ/σ)max = 0.001 Δρmax = 1.66 e Å−3 Δρmin = −1.15 e Å−3

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

x y z Uiso*/Ueq Occ. (<1)

Sr1 0.21635 (2) 0.00000 0.73858 (8) 0.00000

Sr2 0.00000 0.50000 0.00000 0.00000

supporting information

sup-2

Acta Cryst. (2007). E63, i19–i21

Al3 0.00000 0.12868 (8) 0.50000 0.00000

Al4 0.00000 0.00000 0.00000 0.00000

O1 0.08364 (10) 0.24773 (13) 0.4294 (3) 0.00000 O2 0.24036 (10) 0.14101 (14) 0.3245 (4) 0.00000 O3 0.35984 (10) 0.14704 (14) −0.0061 (3) 0.00000 O4 0.42704 (9) 0.37941 (13) 0.1108 (3) 0.00000 O5 0.06564 (13) 0.00000 0.3873 (4) 0.00000 O6 0.40080 (14) 0.00000 0.4793 (5) 0.00000

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

Sr1 0.01130 (15) 0.01460 (18) 0.0185 (2) 0.00000 −0.00227 (13) 0.00000 Sr2 0.0118 (2) 0.0189 (3) 0.0135 (3) 0.00000 0.00093 (17) 0.00000 Al1 0.0075 (3) 0.0082 (3) 0.0067 (3) −0.0003 (2) 0.0030 (2) −0.0006 (3) Si1 0.0075 (3) 0.0082 (3) 0.0067 (3) −0.0003 (2) 0.0030 (2) −0.0006 (3) Al2 0.0081 (3) 0.0072 (3) 0.0073 (3) −0.0007 (3) 0.0024 (2) −0.0006 (3) Si2 0.0081 (3) 0.0072 (3) 0.0073 (3) −0.0007 (3) 0.0024 (2) −0.0006 (3) Al3 0.0076 (4) 0.0077 (5) 0.0059 (5) 0.00000 0.0032 (4) 0.00000 Al4 0.0077 (6) 0.0078 (6) 0.0063 (7) 0.00000 0.0027 (5) 0.00000 O1 0.0096 (7) 0.0097 (8) 0.0108 (8) −0.0011 (6) 0.0031 (6) −0.0007 (7) O2 0.0083 (7) 0.0122 (8) 0.0201 (10) −0.0021 (6) 0.0029 (7) −0.0002 (7) O3 0.0171 (8) 0.0105 (8) 0.0096 (9) −0.0022 (6) 0.0052 (6) −0.0013 (7) O4 0.0090 (7) 0.0087 (8) 0.0083 (8) −0.0027 (6) 0.0015 (6) −0.0000 (6) O5 0.0068 (9) 0.0084 (11) 0.0050 (11) 0.00000 0.0012 (8) 0.00000 O6 0.0151 (11) 0.0097 (11) 0.0126 (13) 0.00000 0.0005 (9) 0.00000

Geometric parameters (Å, º)

Sr1i_—O5i _{2.3932 (17) Al3}i_{—O4 1.8856 (14)} Sr1i_—O2ii _{2.6832 (18) Al3}i_{—O4 1.8856 (14)} Sr1i_—O2i _{2.6832 (18) Al3}i_—O5i _{1.9253 (17)} Sr1i_{—O3 2.7018 (15) Al3}i_{—O5 1.9253 (17)} Sr1i_{—O3 2.7018 (15) Al3}i_{—O1 1.9417 (17)} Sr1i_{—O4 2.8420 (16) Al3}i_—O1i _{1.9417 (17)}

Sr1i_{—O4 2.8420 (16) Al4—O5 1.849 (2)}

Sr1i_{—O2 3.1967 (18) Al4—O5 1.849 (2)}

Sr1i_{—O2 3.1967 (18) Al4—O4 1.9259 (16)}

Sr1i_—O6i _{3.410 (3) Al4—O4 1.9259 (16)}

Sr1i_—O1ii _{3.4812 (14) Al4—O4 1.9259 (16)}

Sr1i_—O1i _{3.4812 (14) Al4—O4 1.9259 (16)}

Sr2—O6i _{2.527 (2) O1}i_{—O4 2.712 (2)}

Sr2—O6 2.527 (2) O1i_{—O3 2.744 (3)}

Sr2—O3 2.6781 (16) O1i_—O5i _{2.7858 (15)}

Sr2—O3 2.6781 (16) O1i_{—O4 2.7893 (19)}

Sr2—O3 2.6781 (16) O1i_{—O1 2.826 (2)}

Sr2—O3 2.6781 (16) O1i_—O2i _{2.843 (2)}

Sr2—O6 3.158 (3) O1i_{—O6 2.8553 (15)}

Sr2i_{—O1 3.5126 (14) O1}i_{—O3 2.933 (2)}

Sr2i_{—O1 3.5126 (14) O1}i_{—O4 2.966 (2)}

Sr2i_—O1iii _{3.5126 (14) O2}i_{—O4 2.7685 (18)} Sr2i_—O1i _{3.5126 (14) O2}i_—O3i _{2.780 (3)} Al1i_{—O4 1.7226 (15) O2}i_—O6i _{2.796 (2)} Al1i_—O2i _{1.7267 (15) O2}i_{—O2 2.946 (2)}

Al1i_{—O3 1.7595 (17) O2}i_{—O3 2.981 (2)}

Al1i_—O1i _{1.773 (2) O2}i_—O2ii _{3.155 (2)} Al1i_—O5i _{2.9537 (16) O2}i_—O5i _{3.177 (2)}

Si1i_{—O4 1.7226 (15) O2}i_{—O3 3.217 (2)}

Si1i_—O2i _{1.7267 (15) O3—O4 2.785 (2)}

Si1i_{—O3 1.7595 (17) O3—O6 2.799 (2)}

Si1i_—O1i _{1.773 (2) O3—O6}i _{3.229 (3)}

Si1i_—O5i _{2.9537 (16) O3—O3 3.289 (2)}

Al2—O2 1.7141 (17) O4—O5 2.508 (2)

Al2—O6 1.7327 (11) O4—O4 2.698 (2)

Al2—O3 1.741 (2) O4—O4 2.749 (2)

Al2—O1i _{1.7587 (15) O4—O5}i _{2.777 (3)}

Si2—O2 1.7141 (17) O4—O5 2.822 (3)

Si2—O6 1.7327 (11) O5i_{—O5 2.557 (3)}

Si2—O3 1.741 (2) O6—O6 2.948 (3)

Si2—O1i _{1.7587 (15)}

O5i_—Sr1i_—O2ii _{77.25 (5) Sr1}i_{—O3—O3 52.50 (4)} O5i_—Sr1i_—O2i _{77.25 (5) O1—O3—O2 149.76 (7)} O5i_—Sr1i_{—O3 141.50 (3) O1—O3—O4 64.87 (6)} O5i_—Sr1i_{—O3 141.50 (3) O1—O3—O6 148.90 (8)} O5i_—Sr1i_{—O4 63.40 (6) O1—O3—O1 119.37 (7)} O5i_—Sr1i_{—O4 63.40 (6) O1—O3—O2 59.38 (6)} O5i_—Sr1i_{—O2 117.56 (5) O1—O3—O2}i _{56.39 (5)} O5i_—Sr1i_{—O2 117.56 (5) O1—O3—O6}i _{56.41 (5)} O2ii_—Sr1i_—O2i _{72.01 (5) O1—O3—O3 115.40 (7)} O2ii_—Sr1i_{—O3 73.37 (5) O2—O3—O4 99.50 (7)} O2ii_—Sr1i_{—O3 115.43 (5) O2—O3—O6 60.16 (7)} O2ii_—Sr1i_{—O4 102.23 (5) O2—O3—O1 59.71 (6)} O2ii_—Sr1i_{—O4 140.34 (4) O2—O3—O2 90.40 (7)} O2ii_—Sr1i_{—O2 112.66 (5) O2—O3—O2}i _{109.43 (6)} O2ii_—Sr1i_{—O2 164.89 (4) O2—O3—O6}i _{139.56 (7)} O2i_—Sr1i_{—O3 115.43 (5) O2—O3—O3 88.61 (6)} O2i_—Sr1i_{—O3 73.37 (5) O4—O3—O6 113.79 (6)} O2i_—Sr1i_{—O4 140.34 (4) O4—O3—O1 56.55 (5)} O2i_—Sr1i_{—O4 102.23 (5) O4—O3—O2 57.27 (5)} O2i_—Sr1i_{—O2 164.89 (4) O4—O3—O2}i _{106.43 (6)} O2i_—Sr1i_{—O2 112.66 (5) O4—O3—O6}i _{119.30 (8)}

O3—Sr1i_{—O3 75.00 (5) O4—O3—O3 158.95 (6)}

O3—Sr1i_{—O4 99.21 (5) O6—O3—O1 59.70 (5)}

supporting information

sup-4

Acta Cryst. (2007). E63, i19–i21

O3—Sr1i_{—O2 55.48 (5) O6—O3—O2}i _{139.49 (7)} O3—Sr1i_{—O2 91.95 (4) O6—O3—O6}i _{108.61 (6)} O3—Sr1i_{—O4 137.55 (5) O6—O3—O3 54.01 (5)}

O3—Sr1i_{—O4 99.21 (5) O1—O3—O2 97.68 (6)}

O3—Sr1i_{—O2 91.95 (4) O1—O3—O2}i _{153.41 (7)} O3—Sr1i_{—O2 55.48 (5) O1—O3—O6}i _{152.61 (7)}

O4—Sr1i_{—O4 56.67 (4) O1—O3—O3 113.66 (6)}

O4—Sr1i_{—O2 54.19 (4) O2—O3—O2}i _{56.60 (5)} O4—Sr1i_{—O2 83.30 (4) O2—O3—O6}i _{100.74 (6)}

O4—Sr1i_{—O2 83.30 (4) O2—O3—O3 142.69 (6)}

O4—Sr1i_{—O2 54.19 (4) O2}i_—O3—O6i _{51.42 (5)} O2—Sr1i_{—O2 59.13 (4) O2}i_{—O3—O3 88.80 (5)} O6i_{—Sr2—O6 180.0000 O6}i_{—O3—O3 59.38 (5)} O6i_{—Sr2—O3 103.37 (6) Al1—O4—Al3 140.10 (9)} O6i_{—Sr2—O3 103.37 (6) Al1—O4—Al4 115.20 (9)} O6i_{—Sr2—O3 76.63 (5) Al1—O4—O5 155.40 (11)} O6i_{—Sr2—O3 76.63 (5) Al1—O4—O4 126.59 (7)} O6i_{—Sr2—O6 118.72 (7) Al1—O4—O1}ii _{99.91 (7)} O6i_{—Sr2—O6 61.28 (7) Al1—O4—O4 90.67 (8)} O6—Sr2—O3 76.63 (6) Al1—O4—O5i _{146.98 (10)}

O6—Sr2—O3 76.63 (6) Al1—O4—O1 107.50 (7)

O6—Sr2—O3 103.37 (5) Al1—O4—O5 76.88 (6)

O6—Sr2—O3 103.37 (5) Al1—O4—Sr1i _{101.63 (6)}

O6—Sr2—O6 61.28 (7) Al3—O4—Al4 96.43 (6)

O6—Sr2—O6 118.72 (7) Al3—O4—O5 49.53 (6)

O3—Sr2—O3 75.78 (5) Al3—O4—O4 92.75 (7)

O3—Sr2—O3 104.22 (5) Al3—O4—O1ii _{45.73 (5)}

O3—Sr2—O3 180.0000 Al3—O4—O4 96.31 (6)

O3—Sr2—O6 123.41 (4) Al3—O4—O2 152.06 (9)

O3—Sr2—O6 56.59 (4) Al3—O4—O5i _{43.78 (5)}

O3—Sr2—O3 180.0000 Al3—O4—O3 103.00 (7)

O3—Sr2—O3 104.22 (5) Al3—O4—O1 44.01 (5)

O3—Sr2—O6 123.41 (5) Al3—O4—O5 136.87 (8)

O3—Sr2—O6 56.59 (4) Al3—O4—Sr1i _{90.83 (6)}

O3—Sr2—O3 75.78 (5) Al3—O4—O1 137.07 (8)

O3—Sr2—O6 56.59 (4) Al4—O4—O5 47.05 (5)

O3—Sr2—O6 123.41 (4) Al4—O4—O4 45.54 (5)

O3—Sr2—O6 56.59 (4) Al4—O4—O1ii _{142.15 (7)}

O3—Sr2—O6 123.41 (4) Al4—O4—O4 44.46 (5)

O6—Sr2—O6 180.0000 Al4—O4—O2 107.97 (7)

O3—Al1i_—O5i _{161.33 (7) O5—O4—O2 150.73 (7)} O1i_—Al1i_—O5i _{66.91 (6) O5—O4—O5}i _{57.60 (7)} O4—Si1i_—O2i _{106.76 (8) O5—O4—O3 143.49 (6)} O4—Si1i_{—O3 106.23 (8) O5—O4—O1 63.19 (5)} O4—Si1i_—O1i _{116.10 (8) O5—O4—O5 87.64 (7)} O4—Si1i_—O5i _{68.51 (7) O5—O4—Sr1}i _{100.54 (7)} O2i_—Si1i_{—O3 117.52 (8) O5—O4—O1 122.97 (9)} O2i_—Si1i_—O1i _{108.66 (8) O4—O4—O1}ii _{121.63 (8)} O2i_—Si1i_—O5i _{80.89 (7) O4—O4—O4 90.00 (7)} O3—Si1i_—O1i _{101.96 (8) O4—O4—O2 94.73 (6)} O3—Si1i_—O5i _{161.33 (7) O4—O4—O5}i _{60.94 (5)} O1i_—Si1i_—O5i _{66.91 (6) O4—O4—O3 158.95 (7)}

O2—Al2—O6 108.44 (10) O4—O4—O1 120.66 (6)

O2—Al2—O3 107.15 (8) O4—O4—O5 61.45 (5)

O2—Al2—O1i _{110.13 (9) O4—O4—Sr1}i _{61.67 (5)}

O6—Al2—O3 107.35 (10) O4—O4—O1 118.66 (7)

O6—Al2—O1i _{109.73 (8) O1}ii_{—O4—O4 126.27 (7)} O3—Al2—O1i _{113.87 (8) O1}ii_{—O4—O2 108.67 (7)} O2—Si2—O6 108.44 (10) O1ii_—O4—O5i _{60.99 (5)} O2—Si2—O3 107.15 (8) O1ii_{—O4—O3 64.47 (6)} O2—Si2—O1i _{110.13 (9) O1}ii_{—O4—O1 61.81 (6)} O6—Si2—O3 107.35 (10) O1ii_{—O4—O5 176.70 (7)} O6—Si2—O1i _{109.73 (8) O1}ii_—O4—Sr1i _{77.59 (6)} O3—Si2—O1i _{113.87 (8) O1}ii_{—O4—O1 119.32 (7)} O4—Al3i_{—O4 174.50 (8) O4—O4—O2 110.56 (7)} O4—Al3i_—O5i _{82.31 (7) O4—O4—O5}i _{122.32 (7)}

O4—Al3i_{—O5 93.56 (8) O4—O4—O3 101.88 (7)}

O4—Al3i_{—O1 90.22 (6) O4—O4—O1 64.75 (6)}

O4—Al3i_—O1i _{93.56 (7) O4—O4—O5 53.49 (6)} O4—Al3i_—O5i _{93.56 (8) O4—O4—Sr1}i _{151.13 (7)}

O4—Al3i_{—O5 82.31 (7) O4—O4—O1 58.28 (5)}

O4—Al3i_{—O1 93.56 (7) O2—O4—O5}i _{119.82 (8)} O4—Al3i_—O1i _{90.22 (7) O2—O4—O3 64.92 (5)} O5i_—Al3i_{—O5 83.23 (8) O2—O4—O1 143.55 (7)} O5i_—Al3i_{—O1 170.94 (7) O2—O4—O5 69.25 (6)} O5i_—Al3i_—O1i _{92.18 (7) O2—O4—Sr1}i _{69.45 (5)}

O5—Al3i_{—O1 92.18 (7) O2—O4—O1 59.32 (5)}

O5—Al3i_—O1i _{170.94 (6) O5}i_{—O4—O3 123.15 (8)} O1—Al3i_—O1i _{93.40 (8) O5}i_{—O4—O1 87.66 (6)}

O5—Al4—O5 180.0000 O5i_{—O4—O5 122.20 (6)}

O5—Al4—O4 96.75 (6) O5i_—O4—Sr1i _{50.40 (5)}

O5—Al4—O4 83.25 (6) O5i_{—O4—O1 179.12 (8)}

O5—Al4—O4 83.25 (6) O3—O4—O1 80.32 (6)

O5—Al4—O4 96.75 (6) O3—O4—O5 112.23 (7)

O5—Al4—O4 83.25 (6) O3—O4—Sr1i _{103.69 (6)}

O5—Al4—O4 96.75 (6) O3—O4—O1 56.90 (6)

O5—Al4—O4 96.75 (6) O1—O4—O5 118.20 (8)

supporting information

sup-6

Acta Cryst. (2007). E63, i19–i21

O4—Al4—O4 91.09 (7) O1—O4—O1 93.21 (6)

O4—Al4—O4 180.0000 O5—O4—Sr1i _{103.70 (6)}

O4—Al4—O4 88.91 (7) O5—O4—O1 57.48 (5)

supporting information

sup-8

Acta Cryst. (2007). E63, i19–i21

supporting information

sup-10

Acta Cryst. (2007). E63, i19–i21

O3—O2i_{—O3 123.40 (7) Sr2}i_{—O6—O3 53.79 (5)} O2ii_—O2i_—O5i _{60.23 (5) Sr2}i_{—O6—O3 53.79 (5)} O2ii_—O2i_{—Sr1 60.43 (4) O2—O6—O2 68.68 (7)} O2ii_—O2i_{—O3 91.20 (6) O2—O6—O3 59.59 (6)} O5i_—O2i_{—Sr1 88.67 (5) O2—O6—O3 99.03 (7)} O5i_—O2i_{—O3 97.61 (7) O2—O6—O1 128.49 (8)} Sr1—O2i_{—O3 142.87 (6) O2—O6—O1}i _{60.49 (5)}

Al2—O3—Al1 120.08 (10) O2—O6—O6 143.09 (6)

Al2—O3—Sr2 103.07 (6) O2—O6—Sr2 111.87 (7)

Al2—O3—Sr1i _{98.46 (7) O2—O6—O3 64.07 (6)}

Al2—O3—O1 152.63 (8) O2—O6—O3 97.89 (9)

Al2—O3—O2 36.09 (5) O2—O6—O3 99.03 (7)

Al2—O3—O4 88.70 (7) O2—O6—O3 59.59 (6)

Al2—O3—O6 36.23 (5) O2—O6—O1 60.49 (5)

Al2—O3—O1 33.26 (5) O2—O6—O1i _{128.49 (8)}

Al2—O3—O2 113.20 (8) O2—O6—O6 143.09 (6)

Al2—O3—O2i _{145.24 (8) O2—O6—Sr2 111.87 (7)}

Al2—O3—O6i _{144.59 (8) O2—O6—O3 97.89 (9)}

Al2—O3—O3 86.55 (7) O2—O6—O3 64.07 (6)

Al1—O3—Sr2 114.72 (8) O3—O6—O3 71.99 (7)

Al1—O3—Sr1i _{118.33 (7) O3—O6—O1 134.40 (9)}

Al1—O3—O1 39.19 (6) O3—O6—O1i _{62.49 (5)}

Al1—O3—O2 113.19 (8) O3—O6—O6 90.57 (8)

Al1—O3—O4 36.43 (5) O3—O6—Sr2 53.02 (6)

Al1—O3—O6 150.18 (8) O3—O6—O3 108.61 (5)

Al1—O3—O1 91.28 (7) O3—O6—O3 156.61 (9)

Al1—O3—O2 30.91 (4) O3—O6—O1 62.49 (5)

Al1—O3—O2i _{70.05 (6) O3—O6—O1}i _{134.40 (9)}

Al1—O3—O6i _{94.18 (8) O3—O6—O6 90.57 (8)}

Al1—O3—O3 153.35 (10) O3—O6—Sr2 53.02 (6)

Sr2—O3—Sr1i _{98.72 (5) O3—O6—O3 156.61 (9)}

Sr2—O3—O1 80.74 (6) O3—O6—O3 108.61 (5)

Sr2—O3—O2 129.49 (7) O1—O6—O1i _{162.44 (9)}

Sr2—O3—O4 109.47 (6) O1—O6—O6 87.51 (5)

Sr2—O3—O6 70.39 (6) O1—O6—Sr2 94.67 (6)

Sr2—O3—O1 104.08 (5) O1—O6—O3 114.05 (9)

Sr2—O3—O2 140.07 (8) O1—O6—O3 53.19 (5)

Sr2—O3—O2i _{100.99 (6) O1}i_{—O6—O6 87.51 (5)} Sr2—O3—O6i _{49.58 (4) O1}i_{—O6—Sr2 94.67 (6)}

Sr2—O3—O3 52.11 (4) O1i_{—O6—O3 53.19 (5)}

Sr1i_{—O3—O1 107.82 (6) O1}i_{—O6—O3 114.05 (9)} Sr1i_{—O3—O2 71.33 (5) O6—O6—Sr2 48.74 (6)} Sr1i_{—O3—O4 148.55 (6) O6—O6—O3 112.69 (7)}

Sr1i_{—O3—O6 88.25 (6) O6—O6—O3 112.69 (7)}

Sr1i_—O3—O2i _{53.05 (4) O3—O6—O3 61.24 (6)} Sr1i_—O3—O6i _{69.54 (5)}