α BaCaAlF7

Acta Cryst.(2003). E59, i17±i19 DOI: 10.1107/S1600536803001259 Werner and Weil BaCaAlF₇

i17

inorganic papers

Acta Crystallographica Section E Structure Reports

Online

ISSN 1600-5368

a

-BaCaAlF

Franz Werner and Matthias Weil*

Institute for Chemical Technologies and Analytics, Division of Structural Chemistry, Vienna University of Technology, Getreidemarkt 9/164-SC, A-1060 Vienna, Austria

Correspondence e-mail: [email protected]

Key indicators Single-crystal X-ray study T= 293 K

Mean(Al±F) = 0.002 AÊ Rfactor = 0.019 wRfactor = 0.043

Data-to-parameter ratio = 17.2

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

#2003 International Union of Crystallography Printed in Great Britain ± all rights reserved

-Barium calcium aluminium hepta¯uoride is a member of the isotypic complex ¯uorides of general formula BaCaMF7(M= Al, Ga, Cr). The crystal structure is made up of triple layers which extend parallel to the (001) plane, and are stacked along [001], with a stacking unit ofc/2. The central unit of one triple layer consists of edge-sharing12[CaF8/2] polyhedra, forming a distorted ¯uorite-type arrangement. On both sides of this layer, isolated [AlF6] octahedra are attached by edge-sharing with the central unit. The triple layers are held together by 11-coordinate Ba atoms that are located between the layers.

Comment

Complex ¯uorides are interesting host lattices for doping with rare-earth or transition metal ions to obtain luminescent materials with slightly different characteristics, compared to the widely used oxides (Rubio, 1991; Kubel et al., 1997; Joubertet al., 2001).

Numerous phases in the pseudobinary system MF2±AlF3 with M = Ca, Sr, Ba have been reported, and the corre-sponding structures solved and re®ned from either single-crystal or powder data [M= Ca: CaAlF5(Hemon & Courbion, 1991) and Ca2AlF7 (Domesle & Hoppe, 1980); M= Sr: two polymorphs of SrAlF5 (Von der Muehll et al., 1971; Kubel, 1998; Weilet al., 2001) and Sr5Al2F16 (Weil, 2001);M= Ba: four polymorphic forms of BaAlF5(Domesle & Hoppe, 1982a; Le Bailet al., 1990; Weilet al., 2001), three polymorphic forms of Ba3AlF9(Renaudinet al., 1990; Renaudin et al., 1991; Le Bail, 1993) and Ba3Al2F12 (Domesle & Hoppe, 1982b)], whereas the number of structurally well-characterized compounds in the pseudo-ternary systemMF2±M0F2±AlF3(M,

M0 _{= Ca, Sr, Ba) is restricted to only three representatives,}

Received 7 January 2003 Accepted 14 January 2003 Online 24 January 2003

Figure 1

Powder patterns of-BaCaAlF7. Top: calculated from single-crystal data;

bottom: PDF entry # 27-0090 (ICDD, 2001); 2values are for CuK1

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with composition Ba0.43Sr0.57AlF5 (Kubel, 1998), Sr0.92Ca0.08AlF5 and Sr0.67Ca0.33AlF5 (Weil et al., 2001) (all single-crystal data). Additionally, two more phases with composition SrCaAlF7 and BaCaAlF7 have been reported, each with three polymorphic forms denoted as , and

(Hoffman, 1972). For four modi®cations (all SrCaAlF7 poly-morphs and ±BaCaAlF7), non-indexed powder data are given and their EuII_{activation was measured. The latter phase} is a very interesting candidate as a luminescent material, since it shows a high EuII_{emission line. Fig. 1 shows that the phase} previously described as -BaCaAlF7 is identical to the title compound. Except for an impurity line at 2= 27.4_{, the entry} in the powder diffraction ®le (PDF # 27-0090; ICDD, 2001) is

in agreement with the powder pattern calculated on the basis of the single-crystal structure re®nement.

-BaCaAlF7 is isotypic with BaCaGaF7 and BaCaCrF7 (Holler & Babel, 1985). In accordance with the slightly smaller ionic radius of AlIII _{(0.54 AÊ) with respect to Ga}III_{and Cr}III (both 0.62 AÊ, values from Shannon, 1976), the unit-cell volume of the title compound is slightly smaller (Al: 544 AÊ3_; Ga: 553 AÊ3_{; Cr: 556 AÊ}3_{). The structure is built up from triple} layers, which extend parallel to (001) and consist of a central unit and two side units (Fig. 2). The central unit is composed of edge-sharing12[CaF8/2] polyhedra with distorted square anti-prisms as the corresponding coordination polyhedra. Although the intrapolyhedral geometry differs signi®cantly from that of a cube found in the ideal ¯uorite structure, this arrangement can be considered as part of a distorted CaF2 structure. This assumption is con®rmed by comparable distancesd(Ca1ÐCa2) of 3.703 (1) and 3.902 (1) AÊ, as well as the average CaÐF distance of 2.372 AÊ and the values of thea and b axes, with respect to the distances and the lattice parameter in CaF2itself [d(CaÐCa) = 3.869 AÊ, d(CaÐF) = 2.369 AÊ and a= 5.471 AÊ; values from Zhurovaet al. (1996)]. The side units are made up from isolated [AlF6] octahedra which share common edges with the central ¯uorite-type 12[CaF8/2] layer. The average AlÐF distance of 1.808 AÊ is in the typical range for [AlF6] octahedra found in other complex aluminium ¯uorides. The largest deviation from the ideal octahedral angle is 6.6_{. Two triple layers are stacked along} [001] with a stacking unit ofc/2 and are held together by 11-coordinated Ba atoms. The resulting [BaF11] polyhedron might be described as a distorted tricapped rectangular prism (Fig. 3), with an average BaÐF distance of 2.850 AÊ. The F atoms exhibit either a coordination number (CN) of 3, resulting in a distorted trigonal planar environment (F1, F2 and F4), or CN = 4, with a distorted tetrahedral coordination geometry (F3, F5, F6 and F7).

Experimental

A mixture of 457 mg BaF2 (Riedel-de HaeÈn, 97%), 41 mg CaF2 (Merck, Suprapur) and 44 mg AlF3(CERAC, 99.9%), corresponding to a molar ratio of 5:1:1, was added to 1 g ZnCl2(Aldrich, 98%) and placed in a platinum crucible. The reaction mixture was then heated under atmospheric conditions to 873 K over a period of 2 h. The ¯ux was kept at that temperature for 2 h and then cooled to 473 K over a period of 12 h. After cooling to room temperature, the solidi®ed melt was leached with demineralized water. Colourless plates of the title compound were isolated from the residue. Additionally, tetragonal plates of matlockite-type BaFCl (Sauvage, 1974) were found in the crystal mixture.

Crystal data BaCaAlF7 Mr= 337.40

Monoclinic,P2=n a= 5.3664 (5) AÊ

b= 5.3846 (6) AÊ

c= 18.8262 (19) AÊ

= 92.319 (2)

V= 543.55 (10) AÊ3 Z= 4

Dx= 4.123 Mg mÿ3

MoKradiation Cell parameters from 3828

re¯ections

= 3.2±30.5

= 8.49 mmÿ1 T= 293 (2) K Plate, colourless 0.120.080.06 mm Figure 2

Projection of the crystal structure along [010]; the unit cell and the [AlF6]

octahedra are outlined.

Figure 3

Data collection

Siemens SMART area detector diffractometer

!scans

Absorption correction: multi-scan (SADABS; Sheldrick, 1996)

Tmin= 0.429,Tmax= 0.630 5719 measured re¯ections

1603 independent re¯ections 1477 re¯ections withI> 2(I)

Rint= 0.020 max= 30.5 h=ÿ7!7

k=ÿ7!7

l=ÿ26!26 Re®nement

Re®nement onF2 R[F2_{> 2(F}2_{)] = 0.019} wR(F2_{) = 0.044} S= 1.11 1603 re¯ections 93 parameters

w= 1/[2_(F

o2) + (0.0157P)2

+ 1.3785P]

whereP= (Fo2+ 2Fc2)/3

(/)max< 0.001

max= 0.76 e AÊÿ3

min=ÿ0.72 e AÊÿ3

Extinction correction:SHELXL97 Extinction coef®cient: 0.0038 (3)

Table 1

Selected geometric parameters (AÊ).

BaÐF4i _{2.5498 (16)}

BaÐF1i _{2.6763 (17)}

BaÐF7ii _{2.7542 (17)}

BaÐF1iii _{2.7831 (17)}

BaÐF5i _{2.7860 (17)}

BaÐF6i _{2.8244 (16)}

BaÐF5iv _{2.8660 (18)}

BaÐF7i _{2.9510 (17)}

BaÐF5v _{3.0058 (18)}

BaÐF7vi _{3.0102 (17)}

BaÐF3iv _{3.1421 (17)}

AlÐF1vii _{1.7535 (19)}

AlÐF2vii _{1.8038 (17)}

AlÐF7 1.8047 (18)

AlÐF3 1.8083 (18)

AlÐF5viii _{1.8133 (18)}

AlÐF6ix _{1.8614 (18)}

Ca1ÐF4x _{2.2282 (17)}

Ca1ÐF4 2.2282 (17)

Ca1ÐF3vii _{2.3880 (16)}

Ca1ÐF3xi _{2.3880 (16)}

Ca1ÐF6xii _{2.4102 (16)}

Ca1ÐF6xiii _{2.4102 (16)}

Ca1ÐF2xiv _{2.4609 (18)}

Ca1ÐF2xv _{2.4609 (18)}

Ca2ÐF4xii _{2.2392 (17)}

Ca2ÐF4 2.2392 (17)

Ca2ÐF2 2.3868 (16)

Ca2ÐF2xii _{2.3868 (16)}

Ca2ÐF6xvi _{2.4231 (17)}

Ca2ÐF6xvii _{2.4231 (17)} Ca2ÐF3viii _{2.4389 (17)}

Ca2ÐF3xi _{2.4389 (17)}

Symmetry codes: (i) 1

2ÿx;y;12ÿz; (ii) xÿ12;ÿy;zÿ12; (iii) xÿ12;1ÿy;zÿ12; (iv) 1

2‡x;1ÿy;zÿ12; (v)12ÿx;yÿ1;12ÿz; (vi)12‡x;ÿy;zÿ21; (vii) 1ÿx;1ÿy;1ÿz; (viii)ÿx;1ÿy;1ÿz; (ix)ÿx;ÿy;1ÿz; (x)3

2ÿx;y;32ÿz; (xi)21‡x;1ÿy;12‡z; (xii) 1

2ÿx;y;32ÿz; (xiii) 1‡x;y;z; (xiv) x;yÿ1;z; (xv) 32ÿx;yÿ1;32ÿz; (xvi) 1

2ÿx;1‡y;32ÿz; (xvii)x;1‡y;z.

Data collection:SMART(Siemens, 1996); cell re®nement:SAINT (Siemens, 1996); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics:

ATOMS for Windows (Dowty, 2000); software used to prepare

material for publication:SHELXL97.

References

Domesle, R. & Hoppe, R. (1980).Z. Kristallogr.153, 317±328. Domesle, R. & Hoppe, R. (1982a).Z. Anorg. Allg. Chem.495, 16±26. Domesle, R. & Hoppe, R. (1982b).Z. Anorg. Allg. Chem.495, 27±28. Dowty, E. (2000).ATOMS for Windows. Version 5.1. Shape Software, 521

Hidden Valley Road, Kingsport, TN 37663, USA.

Hemon, A. & Courbion, C. (1991).Acta Cryst.C47, 1302±1303. Hoffman, M. V. (1972).J. Electrochem. Soc.119, 905±909. Holler, H. & Babel, D. (1985).Z. Anorg. Allg. Chem.523, 89±98.

ICDD (2001). The Powder Diffraction File. International Centre for Diffraction Data, 12 Campus Boulevard, Newton Square, PA 19073±3273, USA.

Joubert, M. F., Guyot, Y., Jacquier, B., Chaminade, J. P. & Garcia, A. (2001).J. Fluorine Chem.107, 235±240.

Kubel, F., Hagemann, H. & Bill, H. (1997).Mater. Res. Bull.32, 263±269. Kubel, F. (1998).Z. Anorg. Allg. Chem.624, 1481±1486.

Le Bail, A., FeÂrey, G., Mercier, A. M., de Kozak, A. & SamoueÈl, M. (1990).J. Solid State Chem.89, 282±291.

Le Bail, A. (1993).J. Solid State Chem.103, 287±291.

Renaudin, A., FeÂrey, G., de Kozak, A. & SamoueÈl, M. (1990).Eur. J. Solid State Inorg. Chem.27, 571±580.

Renaudin, A., FeÂrey, G., de Kozak, A. & SamoueÈl, M. (1991).Eur. J. Solid State Inorg. Chem.28, 373±381.

Rubio, O. J. (1991).J. Phys. Chem. Solids,52, 101±174. Sauvage, M. (1974).Acta Cryst.B30, 2786±2787. Shannon, R. D. (1976).Acta Cryst.A32, 751±767.

Sheldrick, G. M. (1996).SADABS. University of GoÈttingen, Germany. Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of

GoÈttingen, Germany.

Siemens (1996).SMARTandSAINT. Siemens Analytical X-ray Instruments Inc., Madison, Wisconsin, USA.

Von der Muehll, R., Anderson, S. & Galy, J. (1971).Acta Cryst.B27, 2345± 2353.

Weil, M., Zobetz, E., Werner, F. & Kubel, F. (2001).Solid State Sci.3, 441±453. Weil, M. (2001).Z. Anorg. Allg. Chem.627, 2669±2672.

Zhurova, E. A., Maximov, B. A., Simonov, V. I. & Sobolev, B. P. (1996).

Kristallogra®ya,41, 438±443.

Acta Cryst.(2003). E59, i17±i19 Werner and Weil BaCaAlF₇

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Acta Cryst. (2003). E59, i17–i19 [doi:10.1107/S1600536803001259]

α

-BaCaAlF

Franz Werner and Matthias Weil

S1. Comment

Complex fluorides are interesting host lattices for doping with rare-earth or transition metal ions to obtain luminescent

materials with slightly different characteristics as compared to the widespread used oxides (Rubio, 1991; Kubel et al.,

1997; Joubert et al., 2001).

Numerous phases in the pseudobinary system MF2—AlF3 with M = Ca, Sr, Ba have been reported and the

corresponding structures solved and refined either from single-crystal or powder data [M = Ca: CaAlF5 (Hemon &

Courbion, 1991) and Ca2AlF7 (Domesle & Hoppe, 1980); M = Sr: two polymorphs of SrAlF5 (von der Muehll et al.,

1971; Kubel, 1998; Weil et al., 2001) and Sr5Al2F16 (Weil, 2001); M = Ba: four polymorphic forms of BaAlF5 (Domesle

& Hoppe, 1982a; Le Bail et al., 1990; Weil et al., 2001), three polymorphic forms of Ba3AlF9 (Renaudin et al., 1990;

Renaudin et al., 1991; Le Bail, 1993) and Ba3Al2F12 (Domesle & Hoppe, 1982b)], whereas the number of structurally well

characterized compounds in the pseudo-ternary system MF2–M′F2–AlF3 (M, M′ = Ca, Sr, Ba) is restricted to only three

representatives, with composition Ba0.43Sr0.57AlF5 (Kubel, 1998), Sr0.92Ca0.08AlF5 and Sr0.67Ca0.33AlF5 (Weil et al., 2001)

(all single-crystal data). Additionally, two more phases with composition SrCaAlF7 and BaCaAlF7 are reported, each with

three polymorphic forms denoted as α, β and γ (Hoffman, 1972). For four modifications (all SrCaAlF7 polymorphs and α

-BaCaAlF7), non-indexed powder data are given and their EuII activation was measured. The latter phase is a very

interesting candidate as a luminescent material since it shows a high EuII _{emission line. Fig. 1 shows that the phase}

previously described as α-BaCaAlF7 is identical to the title compound. Except for an impurity line at 2θ = 27.4°, the entry

in the powder diffraction file (PDF # 27–0090; ICDD, 2001) is in agreement with the powder pattern calculated on the

basis of the single-crystal structure refinement.

α-BaCaAlF7 is isotypic with BaCaGaF7 and BaCaCrF7 (Holler & Babel, 1985). According to the slightly smaller ionic radius of AlIII _{(0.54 Å) with respect to Ga}III _{and Cr}III _{(both 0.62 Å, values from Shannon, 1976), the unit-cell volume of}

the title compound is slightly smaller (Al: 544 Å3_{; Ga: 553 Å}3_{; Cr: 556 Å}3_{). The structure is built up from triple layers}

which extend parallel to (001) and consist of a central unit and two side units (Fig. 2). The central unit is composed of

edge-sharing 2

∞[CaF8/2] polyhedra with distorted square antiprisms as the corresponding coordination figures. Although

the intrapolyhedral geometry differs significantly from that of a cube found in the ideal fluorite structure, this

arrangement can be considered as part of a distorted CaF2 structure. This assumption is confirmed by comparable

distances d(Ca1—Ca2) of 3.703 (1) and 3.902 (1) Å, as well as the average Ca—F distance of 2.372 Å and the value of

the a and b axis with respect to the distances and the lattice parameter in CaF2 itself [d(Ca—Ca) = 3.869 Å, d(Ca—F) =

2.369 Å and a = 5.471 Å; values from Zhurova et al. (1996)]. The side units are made up from isolated [AlF6] octahedra

which share common edges with the central fluorite-type 2

∞[CaF8/2] layer. The average Al—F distance of 1.808 Å is in the

typical range for [AlF6] octahedra found in other complex aluminium fluorides. The largest deviation from the ideal

octahedral angle is 6.6°. Two triple layers are stacked along [001] with a stacking unit of c/2 and are held together by

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prism (Fig. 3), with an average Ba—F distance of 2.850 Å. The F atoms exhibit either a coordination number (CN) of 3,

resulting in a distorted trigonal planar environment (F1, F2 and F4), or CN = 4, with a distorted tetrahedral coordination

geometry (F3, F5, F6 and F7).

S2. Experimental

A mixture of 457 mg BaF2 (Riedel-de Haën, 97%), 41 mg CaF2 (Merck, Suprapur) and 44 mg AlF3 (CERAC, 99.9%),

corresponding to a molar ratio of 5:1:1, was added to 1 g ZnCl2 (Aldrich, 98%) and placed in a platinum crucible. The

reaction mixture was then heated under atmospheric conditions to 873 K over a period of 2 h. The flux was kept at that

temperature for 2 h and then cooled to 473 K over a period of 12 h. After cooling to room temperature, the solidified melt

was leached with demineralized water. Colourless plates of the title compound were isolated from the residue.

Additionally, tetragonal plates of matlockite-type BaFCl (Sauvage, 1974) were found in the crystal mixture.

Figure 1

Powder patterns of α-BaCaAlF7. Top: calculated from single-crystal data; bottom: PDF entry # 27–0090 (ICDD, 2001);

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Figure 2

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Figure 3

Displacement ellipsoid plot of the coordination environment of the Ba atom with ellipsoids drawn at the 75% probability

level.

Barium calcium aluminium heptafluoride

Crystal data BaCaAlF7

Mr = 337.40

Monoclinic, P2/n Hall symbol: -p 2yac a = 5.3664 (5) Å b = 5.3846 (6) Å c = 18.8262 (19) Å β = 92.319 (2)° V = 543.55 (10) Å3

Z = 4

F(000) = 608 Dx = 4.123 Mg m−3

Mo Kα radiation, λ = 0.71073 Å Cell parameters from 3828 reflections θ = 3.3–30.5°

µ = 8.49 mm−1

T = 293 K Plate, colourless 0.12 × 0.08 × 0.06 mm

Data collection Area detector

diffractometer

Radiation source: fine-focus sealed tube Graphite monochromator

ω scans

Absorption correction: multi-scan (SADABS; Sheldrick, 1996) Tmin = 0.429, Tmax = 0.630

5719 measured reflections 1603 independent reflections 1477 reflections with I > 2σ(I) Rint = 0.020

θmax = 30.5°, θmin = 2.2°

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Refinement Refinement on F2 Least-squares matrix: full R[F2 _{> 2σ(F}2_{)] = 0.019}

wR(F2_{) = 0.044}

S = 1.11 1603 reflections 93 parameters 0 restraints

Primary atom site location: structure-invariant direct methods

Secondary atom site location: difference Fourier map

w = 1/[σ2_(F

o2) + (0.0157P)2 + 1.3785P] where P = (Fo2 + 2Fc2)/3

(Δ/σ)max < 0.001 Δρmax = 0.76 e Å−3 Δρmin = −0.72 e Å−3

Extinction correction: SHELXL97, Fc*_{=kFc[1+0.001xFc}2_λ3_/sin(2θ)]-1/4 Extinction coefficient: 0.0038 (3)

Special details

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 F}2_, conventional R-factors R are based on F, with F set to zero for negative F2_{. The threshold expression of F}2 _{> σ(F}2_{) 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₎

x y z Uiso*/Ueq

Ba 0.24906 (3) 0.24041 (3) −0.067757 (8) 0.01162 (7) Al 0.20069 (15) 0.22470 (14) 0.38092 (4) 0.00837 (15) Ca1 0.7500 0.20769 (13) 0.7500 0.00786 (13) Ca2 0.2500 0.68150 (13) 0.7500 0.00703 (13) F1 0.5997 (3) 0.5949 (3) 0.56404 (9) 0.0165 (3) F2 0.5649 (3) 0.8622 (3) 0.68045 (9) 0.0141 (3) F3 0.0901 (3) 0.4812 (3) 0.32626 (9) 0.0133 (3) F4 0.4141 (3) 0.3614 (3) 0.69206 (8) 0.0133 (3) F5 0.0530 (3) 0.7185 (3) 0.56042 (9) 0.0159 (3) F6 0.0154 (3) −0.0288 (3) 0.67494 (8) 0.0122 (3) F7 0.2750 (3) −0.0454 (3) 0.43446 (9) 0.0167 (3)

Atomic displacement parameters (Å2₎

U11 _U22 _U33 _U12 _U13 _U23

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F7 0.0190 (8) 0.0144 (8) 0.0167 (8) 0.0033 (6) 0.0005 (7) 0.0049 (6)

Geometric parameters (Å, º)

Ba—F4i _{2.5498 (16) Ca1—F4}xiii _{2.2282 (17)} Ba—F1i _{2.6763 (17) Ca1—F4 2.2282 (17)} Ba—F7ii _{2.7542 (17) Ca1—F3}vii _{2.3880 (16)} Ba—F1iii _{2.7831 (17) Ca1—F3}xiv _{2.3880 (16)} Ba—F5i _{2.7860 (17) Ca1—F6}xv _{2.4102 (16)} Ba—F6i _{2.8244 (16) Ca1—F6}xvi _{2.4102 (16)} Ba—F5iv _{2.8660 (18) Ca1—F2}xvii _{2.4609 (18)} Ba—F7i _{2.9510 (17) Ca1—F2}xviii _{2.4609 (18)} Ba—F5v _{3.0058 (18) Ca1—Al}x _{3.4086 (9)} Ba—F7vi _{3.0102 (17) Ca1—Al}xix _{3.4086 (9)} Ba—F3iv _{3.1421 (17) Ca1—Ca2}xvi _{3.7025 (7)} Ba—Ali _{3.5178 (9) Ca1—Ca2 3.7025 (7)} Al—F1vii _{1.7535 (19) Ca2—F4}xv _{2.2392 (17)} Al—F2vii _{1.8038 (17) Ca2—F4 2.2392 (17)} Al—F7 1.8047 (18) Ca2—F2 2.3868 (16) Al—F3 1.8083 (18) Ca2—F2xv _{2.3868 (16)} Al—F5viii _{1.8133 (18) Ca2—F6}xx _{2.4231 (17)} Al—F6ix _{1.8614 (18) Ca2—F6}xxi _{2.4231 (17)} Al—Ca1x _{3.4086 (9) Ca2—F3}viii _{2.4389 (17)} Al—Ca2viii _{3.4201 (9) Ca2—F3}xiv _{2.4389 (17)} Al—Bai _{3.5178 (9) Ca2—Al}viii _{3.4201 (9)} Al—Baxi _{3.6427 (8) Ca2—Al}xiv _{3.4201 (9)} Al—Baxii _{3.9106 (8) Ca2—Ca1}xxii _{3.7025 (7)}

supporting information

sup-7

F6i_—Ba—F5iv _{112.66 (5) F3}xiv_—Ca1—F6xvi _{163.38 (6)} F4i_—Ba—F7i _{152.69 (5) F6}xv_—Ca1—F6xvi _{116.22 (8)} F1i_—Ba—F7i _{107.15 (5) F4}xiii_—Ca1—F2xvii _{147.39 (6)} F7ii_—Ba—F7i _{73.51 (6) F4—Ca1—F2}xvii _{73.69 (6)} F1iii_—Ba—F7i _{51.97 (5) F3}vii_—Ca1—F2xvii _{110.94 (6)} F5i_—Ba—F7i _{117.99 (5) F3}xiv_—Ca1—F2xvii _{134.67 (5)} F6i_—Ba—F7i _{112.10 (5) F6}xv_—Ca1—F2xvii _{71.17 (6)} F5iv_—Ba—F7i _{50.75 (5) F6}xvi_—Ca1—F2xvii _{61.58 (5)} F4i_—Ba—F5v _{112.88 (5) F4}xiii_—Ca1—F2xviii _{73.69 (6)} F1i_—Ba—F5v _{155.78 (5) F4—Ca1—F2}xviii _{147.39 (7)} F7ii_—Ba—F5v _{88.15 (5) F3}vii_—Ca1—F2xviii _{134.67 (5)} F1iii_—Ba—F5v _{111.77 (5) F3}xiv_—Ca1—F2xviii _{110.94 (6)} F5i_—Ba—F5v _{136.74 (6) F6}xv_—Ca1—F2xviii _{61.58 (5)} F6i_—Ba—F5v _{52.08 (5) F6}xvi_—Ca1—F2xviii _{71.17 (6)} F5iv_—Ba—F5v _{81.12 (5) F2}xvii_—Ca1—F2xviii _{81.79 (8)} F7i_—Ba—F5v _{60.06 (5) F4}xv_{—Ca2—F4 79.34 (9)} F4i_—Ba—F7vi _{112.88 (5) F4}xv_{—Ca2—F2 151.92 (7)} F1i_—Ba—F7vi _{154.80 (5) F4—Ca2—F2 75.25 (6)} F7ii_—Ba—F7vi _{137.13 (7) F4}xv_—Ca2—F2xv _{75.25 (6)} F1iii_—Ba—F7vi _{113.73 (5) F4—Ca2—F2}xv _{151.92 (7)} F5i_—Ba—F7vi _{88.07 (5) F2—Ca2—F2}xv _{131.87 (9)} F6i_—Ba—F7vi _{52.00 (4) F4}xv_—Ca2—F6xx _{114.63 (6)} F5iv_—Ba—F7vi _{60.92 (5) F4—Ca2—F6}xx _{125.05 (6)} F7i_—Ba—F7vi _{83.08 (5) F2—Ca2—F6}xx _{72.22 (6)} F5v_—Ba—F7vi _{48.98 (5) F2}xv_—Ca2—F6xx _{77.31 (6)} F4i_—Ba—F3iv _{58.84 (5) F4}xv_—Ca2—F6xxi _{125.05 (6)} F1i_—Ba—F3iv _{95.87 (5) F4—Ca2—F6}xxi _{114.63 (6)} F7ii_—Ba—F3iv _{138.91 (5) F2—Ca2—F6}xxi _{77.31 (6)} F1iii_—Ba—F3iv _{127.61 (5) F2}xv_—Ca2—F6xxi _{72.22 (6)} F5i_—Ba—F3iv _{50.21 (4) F6}xx_—Ca2—F6xxi _{99.85 (8)} F6i_—Ba—F3iv _{60.14 (4) F4}xv_—Ca2—F3viii _{73.17 (6)} F5iv_—Ba—F3iv _{99.88 (4) F4—Ca2—F3}viii _{74.72 (6)} F7i_—Ba—F3iv _{146.66 (4) F2—Ca2—F3}viii _{110.68 (6)} F5v_—Ba—F3iv _{105.15 (4) F2}xv_—Ca2—F3viii _{86.55 (6)} F7vi_—Ba—F3iv _{66.75 (4) F6}xx_—Ca2—F3viii _{158.97 (6)} F1vii_—Al—F2vii _{95.58 (9) F6}xxi_—Ca2—F3viii _{61.92 (6)} F1vii_{—Al—F7 90.02 (9) F4}xv_—Ca2—F3xiv _{74.72 (6)} F2vii_{—Al—F7 90.26 (8) F4—Ca2—F3}xiv _{73.17 (6)} F1vii_{—Al—F3 95.26 (9) F2—Ca2—F3}xiv _{86.55 (6)} F2vii_{—Al—F3 93.15 (8) F2}xv_—Ca2—F3xiv _{110.68 (6)} F7—Al—F3 173.40 (9) F6xx_—Ca2—F3xiv _{61.92 (6)} F1vii_—Al—F5viii _{90.13 (9) F6}xxi_—Ca2—F3xiv _{158.97 (6)} F2vii_—Al—F5viii _{173.74 (9) F3}viii_—Ca2—F3xiv _{137.88 (8)}

Symmetry codes: (i) −x+1/2, y, −z+1/2; (ii) x−1/2, −y, z−1/2; (iii) x−1/2, −y+1, z−1/2; (iv) x+1/2, −y+1, z−1/2; (v) −x+1/2, y−1, −z+1/2; (vi) x+1/2, −y,

z−1/2; (vii) −x+1, −y+1, −z+1; (viii) −x, −y+1, −z+1; (ix) −x, −y, −z+1; (x) −x+1, −y, −z+1; (xi) x−1/2, −y, z+1/2; (xii) x−1/2, −y+1, z+1/2; (xiii) −x+3/2, y, −z+3/2; (xiv) x+1/2, −y+1, z+1/2; (xv) −x+1/2, y, −z+3/2; (xvi) x+1, y, z; (xvii) x, y−1, z; (xviii) −x+3/2, y−1, −z+3/2; (xix) x+1/2, −y, z+1/2; (xx) −x+1/2,