Incommensurate modulations of relaxor ferroelectric Ca0.24Ba0.76Nb2O6 (CBN24) and Ca0.31Ba0.69Nb2O6 (CBN31)

Graetsch, H.A.; Pandey, C.S.; Schreuer, J.; Burianek, M.; Mühlberg, M.

doi:10.1107/S2052520614011676

Buy article online - an online subscription or single-article purchase is required to access this article.

Incommensurate modulations of relaxor ferroelectric Ca_0.24Ba_0.76Nb₂O₆ (CBN24) and Ca_0.31Ba_0.69Nb₂O₆ (CBN31)

H. A. Graetsch, C. S. Pandey, J. Schreuer, M. Burianek and M. Mühlberg

CBN crystals show a one- and a two-dimensionally modulated modification. The former is isotypic with orthorhombic Ba₄Na₂Nb₁₀O₃₀ and the latter with the tetragonal tungsten bronze type of crystal structure. The orthorhombic form irreversibly transforms to the tetragonal polymorph at the ferroelectric phase transition near 603 K. Orthorhombic and tetragonal CBN24 slightly differ in the distribution of the Ba and Ca atoms over the incompletely filled Me1 and Me2 sites. The tetragonal symmetry is further broken in orthorhombic CBN24 by different amplitudes of the positional modulations of O atoms which are symmetrically equivalent in the TTB structure. A similar orthorhombic phase of CBN31 could be obtained by quenching from 1473 K.

Keywords: incommensurate modulations; relaxor ferroelectric structures; solid solution series.

Read article Similar articles

Supporting information

	Crystallographic Information File (CIF) https://doi.org/10.1107/S2052520614011676/dk5023sup1.cif Contains datablocks global, cbn24ort, cbn24tet, cbn31
	Structure factor file (CIF format) https://doi.org/10.1107/S2052520614011676/dk5023cbn24ortsup2.hkl Contains datablock I
	Structure factor file (CIF format) https://doi.org/10.1107/S2052520614011676/dk5023cbn24tetsup3.hkl Contains datablock I
	Structure factor file (CIF format) https://doi.org/10.1107/S2052520614011676/dk5023cbn31sup4.hkl Contains datablock I

B-IncStrDB reference: 9692EcLKMW

Computing details top

Data collection: CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) for cbn24ort, cbn24tet; CrysAlis PRO, Agilent Technologies, Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET) (compiled Dec 3 2012,18:21:49) for cbn31. Cell refinement: CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) for cbn24ort, cbn24tet; CrysAlis PRO, Agilent Technologies, Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET) (compiled Dec 3 2012,18:21:49) for cbn31. Data reduction: CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) for cbn24ort, cbn24tet; CrysAlis PRO, Agilent Technologies, Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET) (compiled Dec 3 2012,18:21:49) for cbn31. Program(s) used to solve structure: Jana2006 for cbn24ort. Program(s) used to refine structure: Jana2006 for cbn24ort. Molecular graphics: Diamond 3.0 for cbn24ort. Software used to prepare material for publication: Jana2006 for cbn24ort.

Figures top

(cbn24ort) top

Crystal data top

Ba_0.761Ca_0.239Nb₂O₆	F(000) = 3553
M_r = 395.9	D_x = 5.328 Mg m⁻³
Orthorhombic, X2mm(00γ)000†	Mo Kα radiation, λ = 0.71069 Å
q = 0.663800c*	Cell parameters from 10368 reflections
a = 7.9429 (3) Å	θ = 2.9–23.3°
b = 17.6240 (5) Å	µ = 10.75 mm⁻¹
c = 17.6229 (6) Å	T = 293 K
V = 2466.95 (14) Å³	Plate-like, colourless
Z = 20	0.40 × 0.34 × 0.04 mm

Data collection top

Xcalibur, Sapphire2, large Be window diffractometer	3449 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2633 reflections with I > 3σ(I)
Graphite monochromator	R_int = 0.030
Detector resolution: 8.2495 pixels mm^-1	θ_max = 31.7°, θ_min = 3.0°
ω and π scans	h = −11→11
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −25→24
T_min = 0.081, T_max = 0.672	l = −25→23
20132 measured reflections

Refinement top

Refinement on F	Weighting scheme based on measured s.u.'s w = 1/(σ²(F) + 0.0001F²)
R[F² > 2σ(F²)] = 0.027	(Δ/σ)_max = 0.045
wR(F²) = 0.036	Δρ_max = 1.16 e Å⁻³
S = 1.42	Δρ_min = −0.86 e Å⁻³
3449 reflections	Extinction correction: B-C type 1 Gaussian isotropic (Becker & Coppens, 1974)
212 parameters	Extinction coefficient: 271 (9)
0 restraints	Absolute structure: 1605 of Friedel pairs used in the refinement
45 constraints	Absolute structure parameter: 0.47 (3)

Crystal data top

Ba_0.761Ca_0.239Nb₂O₆	V = 2466.95 (14) Å³
M_r = 395.9	Z = 20
Orthorhombic, X2mm(00γ)000†	Mo Kα radiation
q = 0.663800c*	µ = 10.75 mm⁻¹
a = 7.9429 (3) Å	T = 293 K
b = 17.6240 (5) Å	0.40 × 0.34 × 0.04 mm
c = 17.6229 (6) Å

Data collection top

Xcalibur, Sapphire2, large Be window diffractometer	3449 independent reflections
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	2633 reflections with I > 3σ(I)
T_min = 0.081, T_max = 0.672	R_int = 0.030
20132 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.027	0 restraints
wR(F²) = 0.036	Δρ_max = 1.16 e Å⁻³
S = 1.42	Δρ_min = −0.86 e Å⁻³
3449 reflections	Absolute structure: 1605 of Friedel pairs used in the refinement
212 parameters	Absolute structure parameter: 0.47 (3)

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Ba2a	0.23955	0	0.32733 (2)	0.01729 (14)	0.9596 (19)
Ba2b	0.24174 (12)	0.171915 (19)	0	0.01627 (14)	0.9294 (19)
Nb2a	−0.00389 (13)	0.181810 (18)	0.39127 (2)	0.00714 (12)
Nb2b	−0.00462 (13)	0.10878 (2)	0.181611 (19)	0.00707 (12)
Nb1a	0.0004 (2)	0	0	0.0062 (2)
Nb1b	−0.0010 (2)	0.5	0	0.0059 (2)
Ca1	0.2495 (6)	0.25	0.25	0.0117 (6)	0.532 (5)
O1a	−0.0195 (10)	0.2155 (2)	0.5	0.0104 (13)
O5a	0.2253 (7)	0.18531 (19)	0.3895 (2)	0.0288 (12)
O5b	−0.2740 (6)	0.11246 (18)	0.18543 (19)	0.0228 (12)
O1b	−0.0252 (9)	0	0.2143 (3)	0.0089 (13)
O2a	−0.0346 (6)	0.14432 (19)	0.28490 (18)	0.0223 (12)
O3b	−0.0255 (6)	0.07503 (16)	0.41884 (19)	0.0167 (10)
O2b	−0.0278 (7)	0.21477 (17)	0.1461 (2)	0.0284 (12)
O3a	−0.0280 (6)	0.08193 (17)	0.07499 (18)	0.0152 (9)
O4a	0.2201 (11)	0.5	0	0.019 (2)
O4b	0.2401 (14)	0	0	0.024 (2)
Ca2a	0.23955	0	0.32733 (2)	0.01729 (14)	0.0272
Ca2b	0.24174 (12)	0.171915 (19)	0	0.01627 (14)	0.0304
Ba1	0.2495 (6)	0.25	0.25	0.0117 (6)	0.0274

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ba2a	0.0113 (2)	0.0299 (3)	0.0106 (2)	0	−0.0026 (4)	0
Ba2b	0.0112 (2)	0.0088 (2)	0.0288 (3)	−0.0008 (4)	0	0
Nb2a	0.0074 (2)	0.0057 (2)	0.0082 (2)	−0.0005 (4)	−0.0014 (4)	0.00006 (13)
Nb2b	0.0077 (2)	0.0078 (2)	0.0057 (2)	−0.0004 (4)	−0.0009 (4)	−0.00007 (13)
Nb1a	0.0058 (4)	0.0060 (3)	0.0068 (4)	0	0	0
Nb1b	0.0063 (4)	0.0063 (3)	0.0051 (4)	0	0	0
Ca1	0.0130 (11)	0.0115 (10)	0.0107 (11)	0	0	−0.0023 (7)
O1a	0.019 (2)	0.0076 (19)	0.004 (2)	0.007 (3)	0	0
O5a	0.014 (2)	0.054 (2)	0.019 (2)	0.007 (2)	−0.001 (2)	0.0022 (16)
O5b	0.0111 (19)	0.0252 (18)	0.032 (2)	−0.009 (2)	−0.006 (2)	−0.0115 (14)
O1b	0.007 (2)	0.011 (2)	0.009 (2)	0	0.003 (3)	0
O2a	0.031 (2)	0.0289 (19)	0.0070 (18)	0.001 (2)	0.002 (2)	−0.0084 (15)
O3b	0.028 (2)	0.0055 (13)	0.0165 (17)	−0.007 (2)	−0.001 (2)	−0.0032 (12)
O2b	0.046 (2)	0.0101 (16)	0.029 (2)	0.009 (2)	0.010 (3)	0.0067 (16)
O3a	0.0223 (18)	0.0127 (14)	0.0106 (16)	0.0076 (19)	0.000 (2)	−0.0052 (13)
O4a	0.002 (4)	0.032 (4)	0.024 (4)	0	0	0
O4b	0.024 (4)	0.027 (3)	0.021 (4)	0	0	0
Ca2a	0.0113 (2)	0.0299 (3)	0.0106 (2)	0	−0.0026 (4)	0
Ca2b	0.0112 (2)	0.0088 (2)	0.0288 (3)	−0.0008 (4)	0	0
Ba1	0.0130 (11)	0.0115 (10)	0.0107 (11)	0	0	−0.0023 (7)

Bond lengths (Å) top

	Average	Minimum	Maximum
Ba2a—O5bⁱ	3.194 (5)	2.861 (5)	3.528 (5)
Ba2a—O5bⁱⁱ	3.194 (5)	2.861 (5)	3.528 (5)
Ba2a—O1b	2.898 (9)	2.795 (9)	3.000 (9)
Ba2a—O1bⁱ	2.733 (9)	2.693 (9)	2.774 (9)
Ba2a—O3b	2.965 (6)	2.830 (6)	3.100 (6)
Ba2a—O3bⁱ	2.801 (6)	2.720 (6)	2.885 (6)
Ba2a—O3bⁱⁱⁱ	2.965 (6)	2.830 (6)	3.100 (6)
Ba2a—O3bⁱⁱ	2.801 (6)	2.720 (6)	2.885 (6)
Ba2a—O4a^iv	3.045 (4)	2.808 (8)	3.286 (8)
Ba2b—O1a^v	2.873 (7)	2.807 (9)	2.938 (9)
Ba2b—O1a^vi	2.746 (7)	2.691 (9)	2.803 (9)
Ba2b—O5a^v	3.187 (5)	2.843 (5)	3.526 (5)
Ba2b—O5a^vii	3.187 (5)	2.843 (5)	3.526 (5)
Ba2b—O3aⁱ	2.762 (6)	2.691 (6)	2.840 (6)
Ba2b—O3a^viii	2.762 (6)	2.691 (6)	2.840 (6)
Nb2a—O1a	2.012 (5)	1.981 (8)	2.039 (8)
Nb2a—O5a	1.833 (8)	1.824 (8)	1.849 (8)
Nb2a—O3b	1.955 (6)	1.947 (6)	1.963 (6)
Nb2a—O2b^vii	1.956 (6)	1.946 (6)	1.966 (6)
Nb2b—O5bⁱ	1.848 (8)	1.829 (8)	1.866 (8)
Nb2b—O2a	1.948 (7)	1.934 (7)	1.960 (7)
Nb2b—O2b	1.985 (6)	1.977 (6)	1.998 (6)
Nb2b—O3a	1.951 (7)	1.944 (7)	1.963 (7)
Nb1a—O3a	1.976 (6)	1.965 (6)	1.988 (6)
Nb1a—O3aⁱⁱⁱ	1.976 (6)	1.965 (6)	1.988 (6)
Nb1a—O3a^ix	1.976 (6)	1.965 (6)	1.988 (6)
Nb1a—O3a^x	1.976 (6)	1.965 (6)	1.988 (6)
Nb1a—O4b	1.917 (14)	1.893 (17)	1.930 (12)
Nb1b—O3b^xi	1.961 (6)	1.956 (7)	1.970 (6)
Nb1b—O3b^v	1.961 (6)	1.956 (7)	1.970 (6)
Nb1b—O3b^xii	1.961 (6)	1.956 (7)	1.970 (6)
Nb1b—O3b^vii	1.961 (6)	1.956 (7)	1.970 (6)
Nb1b—O4a	1.764 (11)	1.755 (13)	1.771 (9)
O5a—Ba1	2.725 (5)	2.583 (6)	2.852 (6)
O5b—Ba1^xiii	2.695 (5)	2.658 (5)	2.738 (5)
O2a—Ba1	2.991 (7)	2.776 (7)	3.207 (8)
O2a—Ba1^xiii	2.610 (7)	2.487 (7)	2.738 (7)
O2b—Ba1	2.930 (8)	2.687 (8)	3.176 (8)
O2b—Ba1^xiii	2.625 (8)	2.545 (8)	2.715 (8)

Symmetry codes: (i) x₁+1/2, x₂, x₃, x₄+1/2; (ii) x₁+1/2, −x₂, x₃, x₄+1/2; (iii) x₁, −x₂, x₃, x₄; (iv) x₁, x₂−1/2, x₃+1/2, x₄; (v) x₁, −x₂+1/2, x₃−1/2, x₄; (vi) x₁+1/2, −x₂+1/2, x₃−1/2, x₄+1/2; (vii) x₁, −x₂+1/2, −x₃+1/2, −x₄; (viii) x₁+1/2, x₂, −x₃, −x₄+1/2; (ix) x₁, x₂, −x₃, −x₄; (x) x₁, −x₂, −x₃, −x₄; (xi) x₁, x₂+1/2, x₃−1/2, x₄; (xii) x₁, x₂+1/2, −x₃+1/2, −x₄; (xiii) x₁−1/2, x₂, x₃, x₄+1/2.

(cbn24tet) top

Crystal data top

Ba_0.761Ca_0.239Nb₂O₆	F(000) = 1773
M_r = 395.9	D_x = 5.349 Mg m⁻³
Tetragonal, X4bm†	Mo Kα radiation, λ = 0.7107 Å
q₁ = 0.309425a* + 0.309425b; q₂ = -0.309425a + 0.309425b*	Cell parameters from 14376 reflections
a = 12.4476 (4) Å	θ = 2.8–42.5°
c = 7.9291 (4) Å	µ = 10.83 mm⁻¹
V = 1228.56 (8) Å³	T = 293 K
Z = 10	0.38 × 0.23 × 0.07 mm

† Symmetry operations: (1) x₁, x₂, x₃, x₄, x₅; (2) −x₂, x₁, x₃, −x₅, x₄; (3) −x₁+1/2, x₂+1/2, x₃, x₅, x₄; (4) −x₁, −x₂, x₃, −x₄, −x₅; (5) −x₂+1/2, −x₁+1/2, x₃, −x₄, x₅; (6) x₂, −x₁, x₃, x₅, −x₄; (7) x₁+1/2, −x₂+1/2, x₃, −x₅, −x₄; (8) x₂+1/2, x₁+1/2, x₃, x₄, −x₅; (9) x₁, x₂, x₃+1/2, x₄+1/2, x₅+1/2; (10) −x₂, x₁, x₃+1/2, −x₅+1/2, x₄+1/2; (11) −x₁+1/2, x₂+1/2, x₃+1/2, x₅+1/2, x₄+1/2; (12) −x₁, −x₂, x₃+1/2, −x₄+1/2, −x₅+1/2; (13) −x₂+1/2, −x₁+1/2, x₃+1/2, −x₄+1/2, x₅+1/2; (14) x₂, −x₁, x₃+1/2, x₅+1/2, −x₄+1/2; (15) x₁+1/2, −x₂+1/2, x₃+1/2, −x₅+1/2, −x₄+1/2; (16) x₂+1/2, x₁+1/2, x₃+1/2, x₄+1/2, −x₅+1/2.

Data collection top

Xcalibur, Sapphire2, large Be window diffractometer	2905 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2299 reflections with I > 3σ(I)
Graphite monochromator	R_int = 0.038
Detector resolution: 8.2495 pixels mm^-1	θ_max = 42.6°, θ_min = 2.9°
ω and π scans	h = −19→23
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −22→23
T_min = 0.11, T_max = 0.654	l = −14→13
59030 measured reflections

Refinement top

Refinement on F	Weighting scheme based on measured s.u.'s w = 1/(σ²(F) + 0.0001F²)
R[F² > 2σ(F²)] = 0.027	(Δ/σ)_max = 0.021
wR(F²) = 0.039	Δρ_max = 0.00 e Å⁻³
S = 1.48	Δρ_min = −0.58 e Å⁻³
2905 reflections	Extinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)
152 parameters	Extinction coefficient: 198 (14)
0 restraints	Absolute structure: 1407 of Friedel pairs used in the refinement
3 constraints	Absolute structure parameter: 0.45 (3)

Crystal data top

Ba_0.761Ca_0.239Nb₂O₆	V = 1228.56 (8) Å³
M_r = 395.9	Z = 10
Tetragonal, X4bm†	Mo Kα radiation
q₁ = 0.309425a* + 0.309425b; q₂ = -0.309425a + 0.309425b*	µ = 10.83 mm⁻¹
a = 12.4476 (4) Å	T = 293 K
c = 7.9291 (4) Å	0.38 × 0.23 × 0.07 mm

Data collection top

Xcalibur, Sapphire2, large Be window diffractometer	2905 independent reflections
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	2299 reflections with I > 3σ(I)
T_min = 0.11, T_max = 0.654	R_int = 0.038
59030 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.027	0 restraints
wR(F²) = 0.039	Δρ_max = 0.00 e Å⁻³
S = 1.48	Δρ_min = −0.58 e Å⁻³
2905 reflections	Absolute structure: 1407 of Friedel pairs used in the refinement
152 parameters	Absolute structure parameter: 0.45 (3)

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Ba2	0.172267 (15)	0.672267 (15)	0.25	0.01616 (9)	0.9382 (8)
Ca1	0	0	0.2583 (6)	0.0105 (6)	0.524 (2)
Nb1	0	0.5	0.00929 (17)	0.00571 (13)
Nb2	0.07295 (2)	0.20951 (2)	0.00540 (11)	0.00674 (10)
O1	0.21501 (17)	0.28499 (17)	−0.0113 (9)	0.0098 (8)
O2	0.1401 (2)	0.0697 (2)	−0.0210 (6)	0.0236 (9)
O3	−0.00673 (18)	0.34333 (18)	−0.0176 (5)	0.0133 (7)
O4	0	0.5	0.2381 (11)	0.0192 (12)
O5	0.07402 (19)	0.2031 (2)	0.2350 (5)	0.0188 (8)
Ca2	0.172267 (15)	0.672267 (15)	0.25	0.01616 (9)	0.0322
Ba1	0	0	0.2583 (6)	0.0105 (6)	0.0261 (16)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ba2	0.01854 (15)	0.01854 (15)	0.01139 (18)	−0.00959 (11)	0.0005 (2)	0.0005 (2)
Ca1	0.0100 (8)	0.0100 (8)	0.0113 (12)	0	0	0
Nb1	0.00524 (18)	0.00524 (18)	0.0067 (3)	−0.00036 (19)	0	0
Nb2	0.00611 (17)	0.00623 (17)	0.0079 (2)	0.00114 (9)	0.0003 (3)	0.0003 (3)
O1	0.0077 (9)	0.0077 (9)	0.0140 (19)	0.0024 (11)	0.0023 (15)	−0.0023 (15)
O2	0.0233 (15)	0.0124 (13)	0.0350 (19)	0.0118 (11)	−0.0029 (17)	−0.0065 (16)
O3	0.0111 (11)	0.0108 (12)	0.0179 (13)	0.0057 (8)	−0.0055 (13)	−0.0001 (14)
O4	0.0222 (15)	0.0222 (15)	0.013 (3)	−0.0023 (18)	0	0
O5	0.0245 (14)	0.0196 (13)	0.0124 (16)	−0.0054 (10)	0.0044 (16)	0.0044 (16)
Ca2	0.01854 (15)	0.01854 (15)	0.01139 (18)	−0.00959 (11)	0.0005 (2)	0.0005 (2)
Ba1	0.0100 (8)	0.0100 (8)	0.0113 (12)	0	0	0

Bond lengths (Å) top

	Average	Minimum	Maximum
Ba2—O1ⁱ	2.856 (8)	2.826 (8)	2.915 (8)
Ba2—O1ⁱⁱ	2.734 (8)	2.715 (8)	2.771 (8)
Ba2—O2ⁱ	3.441 (9)	3.384 (8)	3.468 (9)
Ba2—O2ⁱⁱ	3.204 (9)	3.154 (9)	3.303 (9)
Ba2—O2ⁱⁱⁱ	3.438 (9)	3.380 (8)	3.468 (9)
Ba2—O2^iv	3.241 (9)	3.179 (9)	3.275 (9)
Ba2—O3^v	2.962 (7)	2.836 (7)	3.106 (7)
Ba2—O3^vi	2.772 (7)	2.702 (7)	2.861 (7)
Ba2—O3^vii	2.917 (7)	2.817 (7)	3.123 (7)
Ba2—O3^viii	2.746 (7)	2.689 (7)	2.872 (7)
Ba2—O4	3.083 (5)	2.864 (5)	3.208 (5)
Ba2—O5ⁱ	3.256 (7)	2.878 (7)	3.490 (7)
Ba2—O5^v	3.370 (6)	3.076 (6)	3.803 (6)
Ba2—O5^vii	3.563 (6)	3.068 (6)	3.811 (6)
Ba2—O5ⁱⁱⁱ	3.145 (7)	3.067 (7)	3.303 (7)
Ba2—Ca2	0	0	0
Ca1—Nb2	3.412 (4)	3.401 (4)	3.425 (4)
Ca1—Nb2^ix	3.385 (4)	3.382 (4)	3.390 (4)
Ca1—Nb2^x	3.412 (4)	3.401 (4)	3.425 (4)
Ca1—Nb2^xi	3.385 (4)	3.382 (4)	3.390 (4)
Ca1—Nb2^xii	3.412 (4)	3.401 (4)	3.425 (4)
Ca1—Nb2^xiii	3.385 (4)	3.382 (4)	3.390 (4)
Ca1—Nb2^xiv	3.412 (4)	3.401 (4)	3.425 (4)
Ca1—Nb2^xv	3.385 (4)	3.382 (4)	3.390 (4)
Ca1—O2	2.956 (10)	2.632 (10)	3.273 (10)
Ca1—O2^ix	2.626 (9)	2.508 (9)	2.766 (10)
Ca1—O2^x	2.956 (10)	2.632 (10)	3.273 (10)
Ca1—O2^xi	2.626 (9)	2.508 (9)	2.766 (10)
Ca1—O2^xii	2.956 (10)	2.632 (10)	3.273 (10)
Ca1—O2^xiii	2.626 (9)	2.508 (9)	2.766 (10)
Ca1—O2^xiv	2.956 (10)	2.632 (10)	3.273 (10)
Ca1—O2^xv	2.626 (9)	2.508 (9)	2.766 (10)
Ca1—O5	2.712 (6)	2.693 (6)	2.764 (6)
Ca1—O5^x	2.712 (6)	2.693 (6)	2.764 (6)
Ca1—O5^xii	2.712 (6)	2.693 (6)	2.764 (6)
Ca1—O5^xiv	2.712 (6)	2.693 (6)	2.764 (6)
Ca1—Ba1	0	0	0
Nb1—O3	1.969 (8)	1.961 (8)	1.985 (8)
Nb1—O3^v	1.971 (8)	1.959 (8)	1.980 (8)
Nb1—O3^vii	1.972 (8)	1.962 (8)	1.980 (8)
Nb1—O3^xvi	1.971 (8)	1.955 (8)	1.979 (8)
Nb1—O4	1.831 (10)	1.819 (10)	1.840 (10)
Nb1—O4^xvii	2.163 (10)	2.161 (10)	2.166 (10)
Nb2—O1	2.003 (8)	1.987 (8)	2.027 (8)
Nb2—O2	1.956 (9)	1.942 (9)	1.978 (9)
Nb2—O2^x	1.998 (9)	1.983 (9)	2.027 (9)
Nb2—O3	1.955 (8)	1.944 (8)	1.969 (8)
Nb2—O5	1.841 (9)	1.821 (9)	1.878 (9)
Nb2—O5^xvii	2.173 (9)	2.137 (9)	2.207 (9)
Nb2—Ba1	3.412 (4)	3.401 (4)	3.425 (4)
Nb2—Ba1^xvii	3.387 (4)	3.382 (4)	3.390 (4)
O1—O2	2.839 (12)	2.792 (12)	2.903 (12)
O1—O2^vii	2.834 (12)	2.812 (12)	2.893 (12)
O1—O3	2.858 (11)	2.831 (11)	2.879 (11)
O1—O3^vii	2.866 (11)	2.827 (11)	2.891 (11)
O1—O5	2.835 (11)	2.778 (12)	2.934 (11)
O1—O5^xvii	2.864 (11)	2.788 (12)	2.990 (11)
O1—O5^vii	2.820 (11)	2.788 (12)	2.873 (11)
O1—O5^xviii	2.889 (11)	2.812 (12)	2.933 (11)
O1—Ca2^xix	2.886 (8)	2.764 (8)	2.979 (8)
O1—Ca2^xx	2.740 (8)	2.686 (8)	2.805 (8)
O2—O2^xvii	3.960 (11)	3.324 (11)	4.620 (11)
O2—O2^ix	3.976 (11)	3.324 (11)	4.620 (11)
O2—O2^x	2.795 (13)	2.739 (13)	2.838 (13)
O2—O2^xiv	2.795 (13)	2.739 (13)	2.838 (13)
O2—O3^xiv	2.648 (12)	2.607 (12)	2.697 (12)
O2—O5	2.770 (11)	2.745 (11)	2.812 (12)
O2—O5^xvii	2.711 (11)	2.674 (11)	2.753 (11)
O2—O5^xiv	2.840 (12)	2.801 (12)	2.883 (12)
O2—O5^xxi	2.777 (12)	2.738 (12)	2.841 (12)
O2—Ca2^xix	3.451 (9)	3.360 (9)	3.499 (8)
O2—Ca2^xx	3.201 (9)	3.018 (9)	3.445 (9)
O2—Ba1	2.956 (10)	2.632 (10)	3.273 (10)
O2—Ba1^xvii	2.627 (9)	2.508 (9)	2.766 (10)
O3—O3^vii	2.896 (11)	2.838 (11)	2.929 (11)
O3—O3^xvi	2.652 (11)	2.650 (11)	2.655 (11)
O3—O4	2.829 (11)	2.815 (11)	2.856 (11)
O3—O4^xvii	2.764 (11)	2.746 (11)	2.791 (11)
O3—O5	2.859 (11)	2.796 (11)	2.972 (11)
O3—O5^xvii	2.833 (11)	2.762 (11)	2.944 (11)
O3—Ca2^v	2.971 (7)	2.804 (7)	3.137 (7)
O3—Ca2^xxii	2.773 (7)	2.681 (8)	2.879 (7)
O4—O5	3.852 (8)	3.318 (8)	4.327 (8)
O4—O5^v	3.782 (8)	3.309 (8)	4.313 (8)
O4—O5^vii	3.986 (8)	3.315 (8)	4.309 (8)
O4—O5^xvi	3.648 (8)	3.311 (8)	4.330 (8)
O4—Ca2	3.083 (5)	2.864 (5)	3.208 (5)
O4—Ca2^v	2.983 (5)	2.877 (5)	3.196 (5)
O5—O5^x	3.804 (9)	3.187 (9)	4.425 (9)
O5—O5^xiv	3.804 (9)	3.187 (9)	4.425 (9)
O5—Ca2^xix	3.199 (7)	2.708 (7)	3.661 (7)
O5—Ca2^v	3.465 (6)	2.934 (7)	3.942 (6)
O5—Ba1	2.712 (6)	2.693 (6)	2.764 (6)

Symmetry codes: (i) −x₁+1/2, x₂+1/2, x₃, x₅, x₄; (ii) −x₁+1/2, x₂+1/2, x₃+1/2, x₅+1/2, x₄+1/2; (iii) x₂, −x₁+1, x₃, x₅, −x₄; (iv) x₂, −x₁+1, x₃+1/2, x₅+1/2, −x₄+1/2; (v) −x₁, −x₂+1, x₃, −x₄, −x₅; (vi) −x₁, −x₂+1, x₃+1/2, −x₄+1/2, −x₅+1/2; (vii) −x₂+1/2, −x₁+1/2, x₃, −x₄, x₅; (viii) −x₂+1/2, −x₁+1/2, x₃+1/2, −x₄+1/2, x₅+1/2; (ix) x₁, x₂, x₃+1/2, x₄+1/2, x₅+1/2; (x) −x₂, x₁, x₃, −x₅, x₄; (xi) −x₂, x₁, x₃+1/2, −x₅+1/2, x₄+1/2; (xii) −x₁, −x₂, x₃, −x₄, −x₅; (xiii) −x₁, −x₂, x₃+1/2, −x₄+1/2, −x₅+1/2; (xiv) x₂, −x₁, x₃, x₅, −x₄; (xv) x₂, −x₁, x₃+1/2, x₅+1/2, −x₄+1/2; (xvi) x₂−1/2, x₁+1/2, x₃, x₄, −x₅; (xvii) x₁, x₂, x₃−1/2, x₄+1/2, x₅+1/2; (xviii) −x₂+1/2, −x₁+1/2, x₃−1/2, −x₄+1/2, x₅+1/2; (xix) −x₂+1, x₁, x₃, −x₅, x₄; (xx) −x₂+1, x₁, x₃−1/2, −x₅+1/2, x₄+1/2; (xxi) x₂, −x₁, x₃−1/2, x₅+1/2, −x₄+1/2; (xxii) −x₁, −x₂+1, x₃−1/2, −x₄+1/2, −x₅+1/2.

(cbn31) top

Crystal data top

Ba_0.693Ca_0.307Nb₂O₆	D_x = 5.256 Mg m⁻³
M_r = 389.3	Mo Kα radiation, λ = 0.7107 Å
Tetragonal, X4bm†	Cell parameters from 18477 reflections
q₁ = 0.294200a* + 0.294200b; q₂ = -0.294200a + 0.294200b*	θ = 3.1–36.8°
a = 12.4608 (5) Å	µ = 10.37 mm⁻¹
c = 7.9185 (7) Å	T = 293 K
V = 1229.52 (13) Å³	'3.08', 3.08
Z = 10	0.34 × 0.25 × 0.09 mm
F(000) = 1750

Data collection top

Xcalibur, Sapphire2, large Be window diffractometer	2905 independent reflections
Radiation source: Enhance (Mo) X-ray Source	2580 reflections with I > 3σ(I)
Graphite monochromator	R_int = 0.026
Detector resolution: 8.2495 pixels mm^-1	θ_max = 36.3°, θ_min = 2.9°
ω and π scans	h = −20→20
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET) (compiled Dec 3 2012,18:21:49) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	k = −19→20
T_min = 0.198, T_max = 0.556	l = −13→12
52003 measured reflections

Refinement top

Refinement on F	Weighting scheme based on measured s.u.'s w = 1/(σ²(F) + 0.0001F²)
R[F² > 2σ(F²)] = 0.030	(Δ/σ)_max = 0.026
wR(F²) = 0.047	Δρ_max = 0.00 e Å⁻³
S = 2.02	Δρ_min = −0.66 e Å⁻³
2905 reflections	Extinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974)
151 parameters	Extinction coefficient: 330 (20)
0 restraints	Absolute structure: 1406 of Friedel pairs used in the refinement
0 constraints	Absolute structure parameter: 0.47 (3)

Crystal data top

Ba_0.693Ca_0.307Nb₂O₆	V = 1229.52 (13) Å³
M_r = 389.3	Z = 10
Tetragonal, X4bm†	Mo Kα radiation
q₁ = 0.294200a* + 0.294200b; q₂ = -0.294200a + 0.294200b*	µ = 10.37 mm⁻¹
a = 12.4608 (5) Å	T = 293 K
c = 7.9185 (7) Å	0.34 × 0.25 × 0.09 mm

Data collection top

Xcalibur, Sapphire2, large Be window diffractometer	2905 independent reflections
Absorption correction: analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET) (compiled Dec 3 2012,18:21:49) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	2580 reflections with I > 3σ(I)
T_min = 0.198, T_max = 0.556	R_int = 0.026
52003 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.030	0 restraints
wR(F²) = 0.047	Δρ_max = 0.00 e Å⁻³
S = 2.02	Δρ_min = −0.66 e Å⁻³
2905 reflections	Absolute structure: 1406 of Friedel pairs used in the refinement
151 parameters	Absolute structure parameter: 0.47 (3)

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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Ba2	0.172006 (17)	0.672006 (17)	0.25	0.01488 (11)	0.8542
Ca1	0	0	0.2575 (6)	0.0105 (5)	0.5904
Nb1	0	0.5	0.01060 (18)	0.00572 (15)
Nb2	0.07330 (2)	0.21001 (2)	0.00552 (12)	0.00671 (12)
O1	0.21579 (18)	0.28421 (18)	−0.0103 (9)	0.0092 (8)
O2	0.1391 (2)	0.0688 (2)	−0.0208 (5)	0.0215 (9)
O3	−0.00672 (19)	0.34339 (18)	−0.0150 (5)	0.0142 (7)
O4	0	0.5	0.2382 (11)	0.0179 (12)
O5	0.07371 (18)	0.20251 (19)	0.2375 (5)	0.0190 (8)
Ca2	0.172006 (17)	0.672006 (17)	0.25	0.01488 (11)	0.0882
Ba1	0	0	0.2575 (6)	0.0105 (5)	0.028

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ba2	0.01669 (17)	0.01669 (17)	0.0112 (2)	−0.00931 (12)	0.0004 (2)	0.0004 (2)
Ca1	0.0092 (6)	0.0092 (6)	0.0132 (11)	0	0	0
Nb1	0.0054 (2)	0.0054 (2)	0.0064 (3)	−0.0004 (2)	0	0
Nb2	0.00595 (18)	0.00593 (19)	0.0082 (2)	0.00098 (9)	0.0003 (3)	−0.0018 (3)
O1	0.0081 (9)	0.0081 (9)	0.0114 (19)	0.0021 (12)	−0.0016 (16)	0.0016 (16)
O2	0.0220 (15)	0.0121 (13)	0.0306 (18)	0.0105 (11)	−0.0041 (16)	−0.0064 (15)
O3	0.0125 (12)	0.0094 (12)	0.0208 (14)	0.0048 (8)	−0.0018 (15)	−0.0007 (15)
O4	0.0231 (15)	0.0231 (15)	0.008 (3)	0.0018 (18)	0	0
O5	0.0213 (13)	0.0222 (12)	0.0135 (17)	−0.0034 (9)	0.0039 (17)	−0.0004 (17)
Ca2	0.01669 (17)	0.01669 (17)	0.0112 (2)	−0.00931 (12)	0.0004 (2)	0.0004 (2)
Ba1	0.0092 (6)	0.0092 (6)	0.0132 (11)	0	0	0

Bond lengths (Å) top

	Average	Minimum	Maximum
Ba2—O1ⁱ	2.845 (8)	2.820 (8)	2.895 (8)
Ba2—O1ⁱⁱ	2.733 (8)	2.714 (8)	2.771 (8)
Ba2—O2ⁱ	3.463 (8)	3.367 (8)	3.506 (8)
Ba2—O2ⁱⁱ	3.236 (8)	3.161 (8)	3.329 (8)
Ba2—O2ⁱⁱⁱ	3.450 (8)	3.366 (8)	3.504 (8)
Ba2—O2^iv	3.260 (8)	3.188 (8)	3.299 (8)
Ba2—O3^v	2.950 (7)	2.833 (7)	3.075 (7)
Ba2—O3^vi	2.787 (7)	2.707 (7)	2.877 (7)
Ba2—O3^vii	2.905 (7)	2.815 (7)	3.092 (7)
Ba2—O3^viii	2.754 (7)	2.690 (7)	2.891 (7)
Ba2—O4	3.071 (5)	2.888 (5)	3.181 (5)
Ba2—O5ⁱ	3.257 (6)	2.850 (6)	3.537 (6)
Ba2—O5^v	3.361 (6)	3.106 (6)	3.778 (6)
Ba2—O5^vii	3.556 (6)	3.099 (6)	3.786 (6)
Ba2—O5ⁱⁱⁱ	3.154 (6)	3.076 (6)	3.313 (6)
Ba2—Ca2	0	0	0
Ca1—Nb2	3.415 (4)	3.405 (4)	3.426 (4)
Ca1—Nb2^ix	3.395 (3)	3.392 (3)	3.402 (3)
Ca1—Nb2^x	3.415 (4)	3.405 (4)	3.426 (4)
Ca1—Nb2^xi	3.395 (3)	3.392 (3)	3.402 (3)
Ca1—Nb2^xii	3.415 (4)	3.405 (4)	3.426 (4)
Ca1—Nb2^xiii	3.395 (3)	3.392 (3)	3.402 (3)
Ca1—Nb2^xiv	3.415 (4)	3.405 (4)	3.426 (4)
Ca1—Nb2^xv	3.395 (3)	3.392 (3)	3.402 (3)
Ca1—O2	2.947 (9)	2.624 (9)	3.246 (9)
Ca1—O2^ix	2.623 (9)	2.503 (8)	2.757 (9)
Ca1—O2^x	2.947 (9)	2.624 (9)	3.246 (9)
Ca1—O2^xi	2.623 (9)	2.503 (8)	2.757 (9)
Ca1—O2^xii	2.947 (9)	2.624 (9)	3.246 (9)
Ca1—O2^xiii	2.623 (9)	2.503 (8)	2.757 (9)
Ca1—O2^xiv	2.947 (9)	2.624 (9)	3.246 (9)
Ca1—O2^xv	2.623 (9)	2.503 (8)	2.757 (9)
Ca1—O5	2.694 (5)	2.655 (5)	2.751 (5)
Ca1—O5^x	2.694 (5)	2.655 (5)	2.751 (5)
Ca1—O5^xii	2.694 (5)	2.655 (5)	2.751 (5)
Ca1—O5^xiv	2.694 (5)	2.655 (5)	2.751 (5)
Ca1—Ba1	0	0	0
Nb1—O3	1.970 (7)	1.961 (8)	1.991 (8)
Nb1—O3^v	1.972 (7)	1.957 (7)	1.977 (7)
Nb1—O3^vii	1.974 (7)	1.963 (7)	1.985 (7)
Nb1—O3^xvi	1.971 (7)	1.953 (8)	1.982 (8)
Nb1—O4	1.816 (10)	1.814 (10)	1.817 (10)
Nb1—O4^xvii	2.168 (10)	2.164 (10)	2.175 (10)
Nb2—O1	2.005 (7)	1.995 (7)	2.020 (7)
Nb2—O2	1.964 (8)	1.950 (8)	1.986 (8)
Nb2—O2^x	2.003 (8)	1.985 (8)	2.029 (8)
Nb2—O3	1.952 (8)	1.943 (8)	1.963 (8)
Nb2—O5	1.854 (9)	1.830 (9)	1.897 (9)
Nb2—O5^xvii	2.147 (9)	2.123 (9)	2.189 (9)
Nb2—Ba1	3.415 (4)	3.405 (4)	3.426 (4)
Nb2—Ba1^xvii	3.399 (3)	3.392 (3)	3.402 (3)
O1—O2	2.849 (11)	2.797 (11)	2.918 (11)
O1—O2^vii	2.843 (11)	2.819 (11)	2.909 (11)
O1—O3	2.876 (10)	2.856 (10)	2.905 (10)
O1—O3^vii	2.877 (10)	2.849 (10)	2.901 (10)
O1—O5	2.850 (11)	2.794 (11)	2.944 (10)
O1—O5^xvii	2.861 (11)	2.785 (11)	2.989 (10)
O1—O5^vii	2.838 (11)	2.795 (11)	2.892 (10)
O1—O5^xviii	2.884 (11)	2.824 (11)	2.916 (11)
O1—Ca2^xix	2.867 (8)	2.758 (8)	2.960 (8)
O1—Ca2^xx	2.740 (8)	2.681 (8)	2.809 (8)
O2—O2^xvii	3.939 (10)	3.338 (10)	4.594 (10)
O2—O2^ix	3.985 (10)	3.338 (10)	4.594 (10)
O2—O2^x	2.774 (11)	2.719 (11)	2.817 (11)
O2—O2^xiv	2.774 (11)	2.719 (11)	2.817 (11)
O2—O3^xiv	2.661 (11)	2.619 (11)	2.707 (11)
O2—O5	2.779 (11)	2.757 (11)	2.828 (11)
O2—O5^xvii	2.692 (11)	2.660 (11)	2.738 (10)
O2—O5^xiv	2.843 (11)	2.809 (11)	2.881 (11)
O2—O5^xxi	2.753 (11)	2.712 (11)	2.817 (11)
O2—Ca2^xix	3.469 (8)	3.354 (8)	3.514 (8)
O2—Ca2^xx	3.210 (8)	3.049 (8)	3.445 (8)
O2—Ba1	2.947 (9)	2.624 (9)	3.246 (9)
O2—Ba1^xvii	2.617 (9)	2.503 (8)	2.757 (9)
O3—O3^xvii	3.987 (9)	3.492 (9)	4.428 (9)
O3—O3^ix	3.933 (9)	3.492 (9)	4.428 (9)
O3—O3^vii	2.894 (11)	2.849 (11)	2.919 (11)
O3—O3^xvi	2.654 (11)	2.636 (11)	2.677 (11)
O3—O4	2.814 (10)	2.808 (10)	2.825 (10)
O3—O4^xvii	2.774 (10)	2.747 (10)	2.813 (11)
O3—O5	2.858 (10)	2.807 (10)	2.957 (10)
O3—O5^xvii	2.835 (10)	2.772 (10)	2.944 (10)
O3—Ca2^v	2.950 (7)	2.802 (7)	3.106 (7)
O3—Ca2^xxii	2.787 (7)	2.678 (7)	2.903 (7)
O4—O5	3.876 (7)	3.349 (7)	4.319 (7)
O4—O5^v	3.779 (7)	3.330 (7)	4.311 (7)
O4—O5^vii	3.991 (7)	3.337 (7)	4.306 (7)
O4—O5^xvi	3.664 (7)	3.341 (7)	4.323 (7)
O4—Ca2	3.071 (5)	2.888 (5)	3.181 (5)
O4—Ca2^v	2.989 (5)	2.897 (5)	3.172 (5)
O5—O5^x	3.781 (8)	3.194 (8)	4.402 (8)
O5—O5^xiv	3.781 (8)	3.194 (8)	4.402 (8)
O5—Ca2^xix	3.214 (6)	2.721 (6)	3.667 (6)
O5—Ca2^v	3.470 (6)	2.941 (6)	3.939 (6)
O5—Ba1	2.694 (5)	2.655 (5)	2.751 (5)

Experimental details

	(cbn24ort)	(cbn24tet)	(cbn31)
Crystal data
Chemical formula	Ba_0.761Ca_0.239Nb₂O₆	Ba_0.761Ca_0.239Nb₂O₆	Ba_0.693Ca_0.307Nb₂O₆
M_r	395.9	395.9	389.3
Crystal system, space group	Orthorhombic, X2mm(00γ)000†	Tetragonal, X4bm‡	Tetragonal, X4bm§
Temperature (K)	293	293	293
Wave vectors	q = 0.663800c*	q₁ = 0.309425a* + 0.309425b; q₂ = -0.309425a + 0.309425b*	q₁ = 0.294200a* + 0.294200b; q₂ = -0.294200a + 0.294200b*
a, b, c (Å)	7.9429 (3), 17.6240 (5), 17.6229 (6)	12.4476 (4), 12.4476 (4), 7.9291 (4)	12.4608 (5), 12.4608 (5), 7.9185 (7)
α, β, γ (°)	90, 90, 90	90, 90, 90	90, 90, 90
V (Å³)	2466.95 (14)	1228.56 (8)	1229.52 (13)
Z	20	10	10
Radiation type	Mo Kα	Mo Kα	Mo Kα
µ (mm⁻¹)	10.75	10.83	10.37
Crystal size (mm)	0.40 × 0.34 × 0.04	0.38 × 0.23 × 0.07	0.34 × 0.25 × 0.09

Data collection
Diffractometer	Xcalibur, Sapphire2, large Be window diffractometer	Xcalibur, Sapphire2, large Be window diffractometer	Xcalibur, Sapphire2, large Be window diffractometer
Absorption correction	Analytical CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	Analytical CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)	Analytical CrysAlis PRO, Agilent Technologies, Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET) (compiled Dec 3 2012,18:21:49) Analytical numeric absorption correction using a multifaceted crystal model based on expressions derived by R.C. Clark & J.S. Reid. (Clark, R. C. & Reid, J. S. (1995). Acta Cryst. A51, 887-897)
T_min, T_max	0.081, 0.672	0.11, 0.654	0.198, 0.556
No. of measured, independent and observed [I > 3σ(I)] reflections	20132, 3449, 2633	59030, 2905, 2299	52003, 2905, 2580
R_int	0.030	0.038	0.026
(sin θ/λ)_max (Å⁻¹)	0.740	0.952	0.834

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.027, 0.036, 1.42	0.027, 0.039, 1.48	0.030, 0.047, 2.02
No. of reflections	3449	2905	2905
No. of parameters	212	152	151
Δρ_max, Δρ_min (e Å⁻³)	1.16, −0.86	0.00, −0.58	0.00, −0.66
Absolute structure	1605 of Friedel pairs used in the refinement	1407 of Friedel pairs used in the refinement	1406 of Friedel pairs used in the refinement
Absolute structure parameter	0.47 (3)	0.45 (3)	0.47 (3)

† Symmetry operations: (1) x₁, x₂, x₃, x₄; (2) x₁, −x₂, x₃, x₄; (3) x₁, x₂, −x₃, −x₄; (4) x₁, −x₂, −x₃, −x₄; (5) x₁, x₂+1/2, x₃+1/2, x₄; (6) x₁, −x₂+1/2, x₃+1/2, x₄; (7) x₁, x₂+1/2, −x₃+1/2, −x₄; (8) x₁, −x₂+1/2, −x₃+1/2, −x₄; (9) x₁+1/2, x₂, x₃, x₄+1/2; (10) x₁+1/2, −x₂, x₃, x₄+1/2; (11) x₁+1/2, x₂, −x₃, −x₄+1/2; (12) x₁+1/2, −x₂, −x₃, −x₄+1/2; (13) x₁+1/2, x₂+1/2, x₃+1/2, x₄+1/2; (14) x₁+1/2, −x₂+1/2, x₃+1/2, x₄+1/2; (15) x₁+1/2, x₂+1/2, −x₃+1/2, −x₄+1/2; (16) x₁+1/2, −x₂+1/2, −x₃+1/2, −x₄+1/2.

‡ Symmetry operations: (1) x₁, x₂, x₃, x₄, x₅; (2) −x₂, x₁, x₃, −x₅, x₄; (3) −x₁+1/2, x₂+1/2, x₃, x₅, x₄; (4) −x₁, −x₂, x₃, −x₄, −x₅; (5) −x₂+1/2, −x₁+1/2, x₃, −x₄, x₅; (6) x₂, −x₁, x₃, x₅, −x₄; (7) x₁+1/2, −x₂+1/2, x₃, −x₅, −x₄; (8) x₂+1/2, x₁+1/2, x₃, x₄, −x₅; (9) x₁, x₂, x₃+1/2, x₄+1/2, x₅+1/2; (10) −x₂, x₁, x₃+1/2, −x₅+1/2, x₄+1/2; (11) −x₁+1/2, x₂+1/2, x₃+1/2, x₅+1/2, x₄+1/2; (12) −x₁, −x₂, x₃+1/2, −x₄+1/2, −x₅+1/2; (13) −x₂+1/2, −x₁+1/2, x₃+1/2, −x₄+1/2, x₅+1/2; (14) x₂, −x₁, x₃+1/2, x₅+1/2, −x₄+1/2; (15) x₁+1/2, −x₂+1/2, x₃+1/2, −x₅+1/2, −x₄+1/2; (16) x₂+1/2, x₁+1/2, x₃+1/2, x₄+1/2, −x₅+1/2.

§ Symmetry operations: (1) x₁, x₂, x₃, x₄, x₅; (2) −x₂, x₁, x₃, −x₅, x₄; (3) −x₁+1/2, x₂+1/2, x₃, x₅, x₄; (4) −x₁, −x₂, x₃, −x₄, −x₅; (5) −x₂+1/2, −x₁+1/2, x₃, −x₄, x₅; (6) x₂, −x₁, x₃, x₅, −x₄; (7) x₁+1/2, −x₂+1/2, x₃, −x₅, −x₄; (8) x₂+1/2, x₁+1/2, x₃, x₄, −x₅; (9) x₁, x₂, x₃+1/2, x₄+1/2, x₅+1/2; (10) −x₂, x₁, x₃+1/2, −x₅+1/2, x₄+1/2; (11) −x₁+1/2, x₂+1/2, x₃+1/2, x₅+1/2, x₄+1/2; (12) −x₁, −x₂, x₃+1/2, −x₄+1/2, −x₅+1/2; (13) −x₂+1/2, −x₁+1/2, x₃+1/2, −x₄+1/2, x₅+1/2; (14) x₂, −x₁, x₃+1/2, x₅+1/2, −x₄+1/2; (15) x₁+1/2, −x₂+1/2, x₃+1/2, −x₅+1/2, −x₄+1/2; (16) x₂+1/2, x₁+1/2, x₃+1/2, x₄+1/2, −x₅+1/2.

Computer programs: CrysAlis PRO, Agilent Technologies, Version 1.171.34.49 (release 20-01-2011 CrysAlis171 .NET) (compiled Jan 20 2011,15:58:25), CrysAlis PRO, Agilent Technologies, Version 1.171.36.24 (release 03-12-2012 CrysAlis171 .NET) (compiled Dec 3 2012,18:21:49), Jana2006, Diamond 3.0.

Subscribe to Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.

E-mail address*
Repeat e-mail address* (for error checking)

Format*	PDF (US $40)
	HTML (US $40)
	PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number (non-UK EC countries only)
Country*

Terms and conditions of use
Contact us

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Text
		Plain Text

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Text
		Plain Text

Search IUCr Journals		doi		Advanced search
Author		volume	page