Structural behaviour of synthetic Co₂SiO₄ at low temperatures

Synthetic Co₂SiO₄ has an olivine structure with isolated SiO₄ groups (space group Pnma) and shows magnetic ordering below 50 K. Single-crystal neutron diffraction was applied to determine precise crystal structure parameters at low temperatures. No structural phase transition was revealed in the temperature range 2.5-300 K. Lattice parameters were determined by high-resolution X-ray powder diffraction between 15 and 300 K. There is a clear evidence of an anomalous thermal expansion related to the magnetic phase transition which can be attributed to magnetostriction.

Computing details

For all compounds, data collection: DIF4, see text; cell refinement: not used; data reduction: PRON2K, see text; program(s) used to solve structure: not used; program(s) used to refine structure: FULLPROF, see text; molecular graphics: DIAMOND, see text.

(300K)

Crystal data

Co2SiO4	Z = 4
Mr = 209.95	lattice constants were taken from powder diffraction (see text)
Orthorhombic, Pnma	Dx = 4.715 Mg m^−3
Hall symbol: -P 2ac 2n	Constant wavelength neutron diffraction radiation, λ = 0.552 Å
a = 10.3005 (1) Å	µ = 0.03 mm^−1
b = 6.0028 (1) Å	T = 300 K
c = 4.7816 (1) Å	Parallelepiped, dark violet
V = 295.66 Å^3	3 × 2 × 2 mm

Data collection

Single-crystal diffractometer HEiDi	1341 reflections with I > 2σ(I)
Radiation source: nuclear reactor	Rint = 0.034
Cu (420) monochromator	θmax = 37.4°, θmin = 5.2°
ω scans	h = −20→21
Absorption correction: numerical TBAR, see text	k = −12→12
Tmin = 0.918, Tmax = 0.946	l = −10→9
2920 measured reflections	3 standard reflections every 360 min
1624 independent reflections	intensity decay: 0.7%

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	0 constraints
R[F^2 > 2σ(F^2)] = 0.034	w = 1/σ^2(Fo^2)
wR(F^2) = 0.054	Δρmax = 0.19 e Å^−3
S = 1.28	Δρmin = −0.17 e Å^−3
1341 reflections	Extinction correction: anisotropic, FULLPROF, see text
46 parameters

Special details

Refinement. Anisotropic extinction coefficients (*10^-3): 0.10 (1), 0.28 (1), 1.23 (4), 0.04 (1), -0.06 (3), -0.04 (6)

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

	x	y	z	Uiso*/Ueq
Co1	0.00000	0.00000	0.00000	0.00507 (17)
Co2	0.27645 (7)	0.25000	0.99143 (15)	0.00512 (18)
Si	0.09491 (4)	0.25000	0.42821 (8)	0.00362 (10)
O1	0.09205 (3)	0.25000	0.76712 (6)	0.00518 (8)
O2	0.44872 (3)	0.25000	0.21560 (6)	0.00531 (8)
O3	0.16419 (2)	0.03363 (3)	0.28171 (4)	0.00594 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.00657 (18)	0.00443 (18)	0.00420 (17)	−0.00098 (16)	−0.00018 (15)	−0.00058 (15)
Co2	0.00445 (17)	0.00567 (18)	0.00525 (18)	0.00000	0.00029 (15)	0.00000
Si	0.00404 (11)	0.00415 (11)	0.00265 (10)	0.00000	0.00006 (9)	0.00000
O1	0.00661 (8)	0.00588 (8)	0.00304 (8)	0.00000	0.00014 (7)	0.00000
O2	0.00435 (8)	0.00661 (8)	0.00497 (8)	0.00000	−0.00005 (7)	0.00000
O3	0.00727 (6)	0.00542 (6)	0.00515 (6)	0.00191 (5)	0.00033 (5)	−0.00027 (5)

Geometric parameters (Å, º)

Co1—O1^i	2.0955 (2)	Si—O3	1.6392 (3)
Co1—O1^ii	2.0955 (2)	Si—O3^x	1.6392 (3)
Co1—O2^iii	2.0929 (2)	O1—Co1^vi	2.0955 (2)
Co1—O2^iv	2.0929 (2)	O1—Co1^xi	2.0955 (2)
Co1—O3	2.1715 (2)	O1—Co2	2.1813 (8)
Co1—O3^v	2.1715 (2)	O1—Si	1.6208 (5)
Co2—O1	2.1813 (8)	O2—Co1^xii	2.0929 (2)
Co2—O2^vi	2.0731 (8)	O2—Co1^vii	2.0929 (2)
Co2—O3^vi	2.2250 (6)	O2—Co2^i	2.0731 (8)
Co2—O3^vii	2.0684 (4)	O2—Si^xii	1.6554 (5)
Co2—O3^viii	2.0684 (4)	O3—Co1	2.1715 (2)
Co2—O3^ix	2.2250 (6)	O3—Co2^i	2.2250 (6)
Si—O1	1.6208 (5)	O3—Co2^iv	2.0684 (4)
Si—O2^iii	1.6554 (5)	O3—Si	1.6392 (3)
O1^i—Co1—O1^xiii	180.000 (18)	O3^xvi—Co2—O3^xvii	110.80 (2)
O1^i—Co1—O2^xiv	86.903 (17)	O3^xvi—Co2—O3^xviii	159.48 (2)
O1^i—Co1—O2^xv	93.097 (8)	O3^xvii—Co2—O3^xviii	88.60 (2)
O1^i—Co1—O3^v	84.874 (14)	O1—Si—O2^xix	113.50 (3)
O1^i—Co1—O3^viii	95.126 (15)	O1—Si—O3^xx	115.80 (3)
O1^xiii—Co1—O2^xiv	93.097 (8)	O1—Si—O3^xxi	115.80 (3)
O1^xiii—Co1—O2^xv	86.903 (17)	O2^xix—Si—O3^xx	102.62 (3)
O1^xiii—Co1—O3^v	95.126 (15)	O2^xix—Si—O3^xxi	102.62 (3)
O1^xiii—Co1—O3^viii	84.874 (14)	O3^xx—Si—O3^xxi	104.81 (2)
O2^xiv—Co1—O2^xv	180.000 (17)	Co1^vi—O1—Co1^xix	91.476 (8)
O2^xiv—Co1—O3^v	74.148 (13)	Co1^vi—O1—Co2^xx	97.63 (3)
O2^xiv—Co1—O3^viii	105.852 (16)	Co1^vi—O1—Si^vii	122.65 (3)
O2^xv—Co1—O3^v	105.852 (16)	Co1^xix—O1—Co2^xx	97.63 (3)
O2^xv—Co1—O3^viii	74.148 (13)	Co1^xix—O1—Si^vii	122.65 (3)
O3^v—Co1—O3^viii	180.000 (17)	Co2^xx—O1—Si^vii	118.41 (5)
O1—Co2—O2^xiii	178.32 (4)	Co1^xxii—O2—Co1^xxiii	91.619 (8)
O1—Co2—O3^xi	81.62 (3)	Co1^xxii—O2—Co2^xxiv	123.50 (4)
O1—Co2—O3^xvi	91.09 (3)	Co1^xxii—O2—Si^xxv	92.31 (2)
O1—Co2—O3^xvii	91.09 (3)	Co1^xxiii—O2—Co2^xxiv	123.50 (4)
O1—Co2—O3^xviii	81.62 (3)	Co1^xxiii—O2—Si^xxv	92.31 (2)
O2^xiii—Co2—O3^xi	97.02 (3)	Co2^xxiv—O2—Si^xxv	124.32 (5)
O2^xiii—Co2—O3^xvi	89.87 (3)	Co1—O3—Co2^xxvi	94.13 (3)
O2^xiii—Co2—O3^xvii	89.87 (3)	Co1—O3—Co2^xxvii	117.03 (3)
O2^xiii—Co2—O3^xviii	97.02 (3)	Co1—O3—Si^vii	89.982 (19)
O3^xi—Co2—O3^xvi	88.60 (2)	Co2^xxvi—O3—Co2^xxvii	129.00 (4)
O3^xi—Co2—O3^xvii	159.48 (2)	Co2^xxvi—O3—Si^vii	91.74 (4)
O3^xi—Co2—O3^xviii	71.43 (2)	Co2^xxvii—O3—Si^vii	125.01 (3)

Symmetry codes: (i) x, y, z−1; (ii) −x, y−1/2, −z+1; (iii) x−1/2, −y+1/2, −z+1/2; (iv) −x+1/2, −y, z−1/2; (v) −x, −y, −z; (vi) x, y, z+1; (vii) −x+1/2, −y, z+1/2; (viii) −x+1/2, y+1/2, z+1/2; (ix) x, −y+1/2, z+1; (x) x, −y+1/2, z; (xi) −x, y+1/2, −z+1; (xii) x+1/2, −y+1/2, −z+1/2; (xiii) x+1/2, −y+1/2, −z+3/2; (xiv) −x, y+3/2, −z+1; (xv) −x+3/2, −y, z+1/2; (xvi) −x+3/2, −y, z+3/2; (xvii) −x+1, −y+1, −z+1; (xviii) −x+1/2, y+3/2, z+3/2; (xix) x+1/2, −y+3/2, −z+3/2; (xx) −x, y+1/2, −z; (xxi) −x+1/2, −y+1, z+1/2; (xxii) x+1, y+1, z+1; (xxiii) x+3/2, −y+1/2, −z+3/2; (xxiv) −x, y+1/2, −z−1; (xxv) −x+3/2, −y+1, z+3/2; (xxvi) x+1/2, −y+1/2, −z−1/2; (xxvii) −x+1, y+1/2, −z.

(55K)

Crystal data

Co2SiO4	Z = 4
Mr = 209.95	lattice constants were taken from powder diffraction (see text)
Orthorhombic, Pnma	Dx = 4.715 Mg m^−3
Hall symbol: -P 2ac 2n	Constant wavelength neutron diffraction radiation, λ = 0.552 Å
a = 10.2869 (1) Å	µ = 0.03 mm^−1
b = 5.9889 (1) Å	T = 55 K
c = 4.7781 (1) Å	Parallelepiped, dark violet
V = 294.37 Å^3	3 × 2 × 2 mm

Data collection

Single-crystal diffractometer HEiDi	1098 reflections with I > 2σ(I)
Radiation source: nuclear reactor	Rint = 0.028
Cu (420) monochromator	θmax = 37.9°, θmin = 3.7°
ω scans	h = −20→22
Absorption correction: numerical TBAR, see text	k = −4→11
Tmin = 0.915, Tmax = 0.947	l = −10→10
2118 measured reflections	3 standard reflections every 360 min
1465 independent reflections	intensity decay: 0.7%

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	0 constraints
R[F^2 > 2σ(F^2)] = 0.029	w = 1/σ^2(Fo^2)
wR(F^2) = 0.035	Δρmax = 0.17 e Å^−3
S = 1.10	Δρmin = −0.13 e Å^−3
1098 reflections	Extinction correction: anisotropic, FULLPROF, see text
46 parameters

Special details

Refinement. Anisotropic extinction coefficients (*10^-3): 0.11 (1), 0.07 (4), 1.27 (4), 0.18 (3), 0.27 (2), 0.03 (4)

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

	x	y	z	Uiso*/Ueq
Co1	0.00000	0.00000	0.00000	0.00173 (19)
Co2	0.27603 (6)	0.25000	0.99136 (14)	0.00174 (19)
Si	0.09489 (4)	0.25000	0.42824 (8)	0.00149 (12)
O1	0.09184 (3)	0.25000	0.76739 (6)	0.00281 (9)
O2	0.44849 (2)	0.25000	0.21578 (6)	0.00269 (9)
O3	0.164278 (18)	0.03324 (4)	0.28116 (4)	0.00294 (7)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.00245 (16)	0.0011 (3)	0.00165 (15)	−0.00016 (11)	0.00004 (12)	−0.00010 (14)
Co2	0.00171 (16)	0.0016 (2)	0.00188 (15)	0.00000	−0.00018 (12)	0.00000
Si	0.00182 (10)	0.00111 (15)	0.00153 (10)	0.00000	−0.00002 (7)	0.00000
O1	0.00346 (8)	0.00295 (13)	0.00201 (8)	0.00000	0.00005 (6)	0.00000
O2	0.00223 (8)	0.00289 (12)	0.00293 (8)	0.00000	0.00006 (6)	0.00000
O3	0.00352 (6)	0.00222 (9)	0.00308 (5)	0.00071 (4)	0.00017 (5)	−0.00014 (5)

Geometric parameters (Å, º)

Co1—O1^i	2.0907 (2)	Si—O3	1.6397 (3)
Co1—O1^ii	2.0907 (2)	Si—O3^x	1.6397 (3)
Co1—O2^iii	2.0896 (2)	O1—Co1^vi	2.0907 (2)
Co1—O2^iv	2.0896 (2)	O1—Co1^xi	2.0907 (2)
Co1—O3	2.1678 (1)	O1—Co2	2.1759 (6)
Co1—O3^v	2.1678 (1)	O1—Si	1.6207 (4)
Co2—O1	2.1759 (6)	O2—Co1^xii	2.0896 (2)
Co2—O2^vi	2.0731 (6)	O2—Co1^vii	2.0896 (2)
Co2—O3^vi	2.2193 (5)	O2—Co2^i	2.0731 (6)
Co2—O3^vii	2.0647 (4)	O2—Si^xii	1.6555 (4)
Co2—O3^viii	2.0647 (4)	O3—Co1	2.1678 (1)
Co2—O3^ix	2.2193 (5)	O3—Co2^i	2.2193 (5)
Si—O1	1.6207 (4)	O3—Co2^iv	2.0647 (4)
Si—O2^iii	1.6555 (4)	O3—Si	1.6397 (3)
O1^i—Co1—O1^xiii	180.000 (14)	O3^xvi—Co2—O3^xvii	110.49 (2)
O1^i—Co1—O2^xiv	86.963 (14)	O3^xvi—Co2—O3^xviii	159.75 (2)
O1^i—Co1—O2^xv	93.037 (6)	O3^xvii—Co2—O3^xviii	88.684 (17)
O1^i—Co1—O3^v	84.915 (11)	O1—Si—O2^xix	113.47 (3)
O1^i—Co1—O3^viii	95.085 (11)	O1—Si—O3^xx	115.90 (2)
O1^xiii—Co1—O2^xiv	93.037 (6)	O1—Si—O3^xxi	115.90 (2)
O1^xiii—Co1—O2^xv	86.963 (14)	O2^xix—Si—O3^xx	102.58 (2)
O1^xiii—Co1—O3^v	95.085 (11)	O2^xix—Si—O3^xxi	102.58 (2)
O1^xiii—Co1—O3^viii	84.915 (11)	O3^xx—Si—O3^xxi	104.69 (2)
O2^xiv—Co1—O2^xv	180.000 (14)	Co1^vi—O1—Co1^xix	91.475 (6)
O2^xiv—Co1—O3^v	74.283 (10)	Co1^vi—O1—Co2^xx	97.59 (2)
O2^xiv—Co1—O3^viii	105.717 (13)	Co1^vi—O1—Si^vii	122.70 (2)
O2^xv—Co1—O3^v	105.717 (13)	Co1^xix—O1—Co2^xx	97.59 (2)
O2^xv—Co1—O3^viii	74.283 (10)	Co1^xix—O1—Si^vii	122.70 (2)
O3^v—Co1—O3^viii	180.000 (12)	Co2^xx—O1—Si^vii	118.37 (4)
O1—Co2—O2^xiii	178.30 (3)	Co1^xxii—O2—Co1^xxiii	91.537 (6)
O1—Co2—O3^xi	81.71 (2)	Co1^xxii—O2—Co2^xxiv	123.59 (3)
O1—Co2—O3^xvi	91.13 (2)	Co1^xxii—O2—Si^xxv	92.266 (17)
O1—Co2—O3^xvii	91.13 (2)	Co1^xxiii—O2—Co2^xxiv	123.59 (3)
O1—Co2—O3^xviii	81.71 (2)	Co1^xxiii—O2—Si^xxv	92.266 (17)
O2^xiii—Co2—O3^xi	96.92 (2)	Co2^xxiv—O2—Si^xxv	124.28 (4)
O2^xiii—Co2—O3^xvi	89.84 (2)	Co1—O3—Co2^xxvi	94.07 (2)
O2^xiii—Co2—O3^xvii	89.84 (2)	Co1—O3—Co2^xxvii	117.24 (2)
O2^xiii—Co2—O3^xviii	96.92 (2)	Co1—O3—Si^vii	89.939 (15)
O3^xi—Co2—O3^xvi	88.684 (17)	Co2^xxvi—O3—Co2^xxvii	129.05 (3)
O3^xi—Co2—O3^xvii	159.75 (2)	Co2^xxvi—O3—Si^vii	91.71 (3)
O3^xi—Co2—O3^xviii	71.60 (2)	Co2^xxvii—O3—Si^vii	124.85 (2)

Symmetry codes: (i) x, y, z−1; (ii) −x, y−1/2, −z+1; (iii) x−1/2, −y+1/2, −z+1/2; (iv) −x+1/2, −y, z−1/2; (v) −x, −y, −z; (vi) x, y, z+1; (vii) −x+1/2, −y, z+1/2; (viii) −x+1/2, y+1/2, z+1/2; (ix) x, −y+1/2, z+1; (x) x, −y+1/2, z; (xi) −x, y+1/2, −z+1; (xii) x+1/2, −y+1/2, −z+1/2; (xiii) x+1/2, −y+1/2, −z+3/2; (xiv) −x, y+3/2, −z+1; (xv) −x+3/2, −y, z+1/2; (xvi) −x+3/2, −y, z+3/2; (xvii) −x+1, −y+1, −z+1; (xviii) −x+1/2, y+3/2, z+3/2; (xix) x+1/2, −y+3/2, −z+3/2; (xx) −x, y+1/2, −z; (xxi) −x+1/2, −y+1, z+1/2; (xxii) x+1, y+1, z+1; (xxiii) x+3/2, −y+1/2, −z+3/2; (xxiv) −x, y+1/2, −z−1; (xxv) −x+3/2, −y+1, z+3/2; (xxvi) x+1/2, −y+1/2, −z−1/2; (xxvii) −x+1, y+1/2, −z.

(2point5K)

Crystal data

Co2SiO4	Z = 4
Mr = 209.95	lattice constants were taken from powder diffraction (see text)
Orthorhombic, Pnma	Dx = 4.715 Mg m^−3
Hall symbol: -P 2ac 2n	Constant wavelength neutron diffraction radiation, λ = 0.552 Å
a = 10.2864 (1) Å	µ = 0.03 mm^−1
b = 5.9872 (1) Å	T = 3 K
c = 4.7785 (1) Å	Parallelepiped, dark violet
V = 294.29 Å^3	3 × 2 × 2 mm

Data collection

Single-crystal diffractometer HEiDi	1070 reflections with I > 2σ(I)
Radiation source: nuclear reactor	Rint = 0.033
Cu (420) monochromator	θmax = 37.9°, θmin = 1.5°
ω scans	h = −22→22
Absorption correction: numerical TBAR, see text	k = −11→11
Tmin = 0.915, Tmax = 0.947	l = −10→10
3226 measured reflections	3 standard reflections every 360 min
1424 independent reflections	intensity decay: 0.7%

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	0 constraints
R[F^2 > 2σ(F^2)] = 0.033	w = 1/σ^2(Fo^2)
wR(F^2) = 0.044	Δρmax = 0.11 e Å^−3
S = 1.49	Δρmin = −0.13 e Å^−3
1070 reflections	Extinction correction: anisotropic, FULLPROF, see text
50 parameters

Special details

Refinement. Anisotropic extinction coefficients (*10^-3): 0.16 (1), 0.35 (4), 1.43 (3), 0.00 (3), 0.27 (2), 0.22 (4)

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

	x	y	z	Uiso*/Ueq
Co1	0.00000	0.00000	0.00000	0.00176 (19)
Co2	0.27597 (6)	0.25000	0.99115 (12)	0.0017 (2)
Si	0.09479 (4)	0.25000	0.42838 (7)	0.00157 (12)
O1	0.09180 (3)	0.25000	0.76731 (5)	0.00282 (9)
O2	0.44854 (2)	0.25000	0.21605 (6)	0.00267 (9)
O3	0.164381 (18)	0.03313 (4)	0.28129 (4)	0.00295 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Co1	0.00235 (14)	0.0013 (3)	0.00161 (13)	−0.00022 (14)	0.00005 (12)	−0.00009 (15)
Co2	0.00234 (15)	0.0008 (3)	0.00204 (14)	0.00000	0.00004 (13)	0.00000
Si	0.00199 (9)	0.00123 (18)	0.00149 (9)	0.00000	0.00012 (7)	0.00000
O1	0.00355 (7)	0.00291 (15)	0.00201 (7)	0.00000	0.00002 (6)	0.00000
O2	0.00232 (7)	0.00278 (15)	0.00291 (7)	0.00000	0.00003 (6)	0.00000
O3	0.00363 (5)	0.00215 (10)	0.00306 (4)	0.00076 (5)	0.00006 (5)	−0.00019 (5)

Geometric parameters (Å, º)

Co1—O1^i	2.0901 (2)	Si—O3	1.6409 (3)
Co1—O1^ii	2.0901 (2)	Si—O3^x	1.6409 (3)
Co1—O2^iii	2.0885 (2)	O1—Co1^vi	2.0901 (2)
Co1—O2^iv	2.0885 (2)	O1—Co1^xi	2.0901 (2)
Co1—O3	2.1691 (2)	O1—Co2	2.1756 (7)
Co1—O3^v	2.1691 (2)	O1—Si	1.6199 (4)
Co2—O1	2.1756 (7)	O2—Co1^xii	2.0885 (2)
Co2—O2^vi	2.0751 (6)	O2—Co1^vii	2.0885 (2)
Co2—O3^vi	2.2194 (5)	O2—Co2^i	2.0751 (6)
Co2—O3^vii	2.0629 (4)	O2—Si^xii	1.6551 (5)
Co2—O3^viii	2.0629 (4)	O3—Co1	2.1691 (2)
Co2—O3^ix	2.2194 (5)	O3—Co2^i	2.2194 (5)
Si—O1	1.6199 (4)	O3—Co2^iv	2.0629 (4)
Si—O2^iii	1.6551 (5)	O3—Si	1.6409 (3)
O1^i—Co1—O1^xiii	180.000 (16)	O3^xvi—Co2—O3^xvii	110.52 (2)
O1^i—Co1—O2^xiv	86.955 (16)	O3^xvi—Co2—O3^xviii	159.76 (2)
O1^i—Co1—O2^xv	93.045 (8)	O3^xvii—Co2—O3^xviii	88.67 (2)
O1^i—Co1—O3^v	84.950 (13)	O1—Si—O2^xix	113.56 (3)
O1^i—Co1—O3^viii	95.050 (15)	O1—Si—O3^xx	115.88 (3)
O1^xiii—Co1—O2^xiv	93.045 (8)	O1—Si—O3^xxi	115.88 (3)
O1^xiii—Co1—O2^xv	86.955 (16)	O2^xix—Si—O3^xx	102.59 (2)
O1^xiii—Co1—O3^v	95.050 (15)	O2^xix—Si—O3^xxi	102.59 (2)
O1^xiii—Co1—O3^viii	84.950 (13)	O3^xx—Si—O3^xxi	104.62 (2)
O2^xiv—Co1—O2^xv	180.000 (17)	Co1^vi—O1—Co1^xix	91.474 (7)
O2^xiv—Co1—O3^v	74.303 (11)	Co1^vi—O1—Co2^xx	97.58 (3)
O2^xiv—Co1—O3^viii	105.697 (15)	Co1^vi—O1—Si^vii	122.72 (2)
O2^xv—Co1—O3^v	105.697 (15)	Co1^xix—O1—Co2^xx	97.58 (3)
O2^xv—Co1—O3^viii	74.303 (11)	Co1^xix—O1—Si^vii	122.72 (2)
O3^v—Co1—O3^viii	180.000 (16)	Co2^xx—O1—Si^vii	118.36 (4)
O1—Co2—O2^xiii	178.26 (3)	Co1^xxii—O2—Co1^xxiii	91.565 (8)
O1—Co2—O3^xi	81.76 (2)	Co1^xxii—O2—Co2^xxiv	123.59 (3)
O1—Co2—O3^xvi	91.15 (2)	Co1^xxii—O2—Si^xxv	92.32 (2)
O1—Co2—O3^xvii	91.15 (2)	Co1^xxiii—O2—Co2^xxiv	123.59 (3)
O1—Co2—O3^xviii	81.76 (2)	Co1^xxiii—O2—Si^xxv	92.32 (2)
O2^xiii—Co2—O3^xi	96.83 (2)	Co2^xxiv—O2—Si^xxv	124.17 (5)
O2^xiii—Co2—O3^xvi	89.85 (2)	Co1—O3—Co2^xxvi	93.99 (3)
O2^xiii—Co2—O3^xvii	89.85 (2)	Co1—O3—Co2^xxvii	117.25 (3)
O2^xiii—Co2—O3^xviii	96.83 (2)	Co1—O3—Si^vii	89.869 (18)
O3^xi—Co2—O3^xvi	88.67 (2)	Co2^xxvi—O3—Co2^xxvii	129.09 (3)
O3^xi—Co2—O3^xvii	159.76 (2)	Co2^xxvi—O3—Si^vii	91.73 (4)
O3^xi—Co2—O3^xviii	71.61 (2)	Co2^xxvii—O3—Si^vii	124.87 (2)

Symmetry codes: (i) x, y, z−1; (ii) −x, y−1/2, −z+1; (iii) x−1/2, −y+1/2, −z+1/2; (iv) −x+1/2, −y, z−1/2; (v) −x, −y, −z; (vi) x, y, z+1; (vii) −x+1/2, −y, z+1/2; (viii) −x+1/2, y+1/2, z+1/2; (ix) x, −y+1/2, z+1; (x) x, −y+1/2, z; (xi) −x, y+1/2, −z+1; (xii) x+1/2, −y+1/2, −z+1/2; (xiii) x+1/2, −y+1/2, −z+3/2; (xiv) −x, y+3/2, −z+1; (xv) −x+3/2, −y, z+1/2; (xvi) −x+3/2, −y, z+3/2; (xvii) −x+1, −y+1, −z+1; (xviii) −x+1/2, y+3/2, z+3/2; (xix) x+1/2, −y+3/2, −z+3/2; (xx) −x, y+1/2, −z; (xxi) −x+1/2, −y+1, z+1/2; (xxii) x+1, y+1, z+1; (xxiii) x+3/2, −y+1/2, −z+3/2; (xxiv) −x, y+1/2, −z−1; (xxv) −x+3/2, −y+1, z+3/2; (xxvi) x+1/2, −y+1/2, −z−1/2; (xxvii) −x+1, y+1/2, −z.