Dicerium disilicate, Ce₂[Si₂O₇]

Dicerium disilicate, Ce₂[Si₂O₇], crystallizes in space group P4₁ of the tetra­gonal system. It has isostructural analogues among the disilicates of the larger rare-earth elements, namely Ln₂[Si₂O₇] (Ln is La, Pr, Nd or Sm). The structure consists of discrete Ce³⁺ cations and [Si₂O₇]^6- anions; the asymmetric unit containing four cations and two anions. Each anion is formed from two SiO₄ tetra­hedra that share a vertex.

Key indicators

• Single-crystal X-ray study
• T = 153 K
• Mean [sigma](i-O) = 0.006 Å
• R factor = 0.024
• wR factor = 0.055
• Data-to-parameter ratio = 13.6

checkCIF/PLATON results

No syntax errors found



Alert level C
STRVA01_ALERT_4_C           Flack test results are ambiguous.
           From the CIF: _refine_ls_abs_structure_Flack    0.522
           From the CIF: _refine_ls_abs_structure_Flack_su    0.019
PLAT033_ALERT_2_C Flack Parameter Value Deviates from Zero .......       0.52
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       2.01

Alert level G
FORMU01_ALERT_1_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and _chemical_formula_moiety. This is
            usually due to the moiety formula being in the wrong format.
            Atom count from _chemical_formula_sum:   Ce4 O14 Si4
            Atom count from _chemical_formula_moiety:
REFLT03_ALERT_1_G ALERT: Expected hkl max differ from CIF values
           From the CIF: _diffrn_reflns_theta_max           28.93
           From the CIF: _reflns_number_total               2729
           From the CIF: _diffrn_reflns_limit_ max hkl    9.    9.   31.
           From the CIF: _diffrn_reflns_limit_ min hkl   -9.   -8.  -31.
           TEST1: Expected hkl limits for theta max
           Calculated maximum hkl    9.    9.   33.
           Calculated minimum hkl   -9.   -9.  -33.
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           28.93
           From the CIF: _reflns_number_total               2729
           Count of symmetry unique reflns         1545
           Completeness (_total/calc)            176.63%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1184
           Fraction of Friedel pairs measured     0.766
           Are heavy atom types Z>Si present        yes

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker,2003); cell refinement: SAINT (Bruker, 2003); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2003); program(s) used to refine structure: SHELXTL (Sheldrick, 2003); molecular graphics: XP in SHELXTL; software used to prepare material for publication: SHELXTL.

Dicerium disilicate

Crystal data

Ce4[Si2O7]2	Dx = 5.215 Mg m^−3
Mr = 896.84	Mo Kα radiation, λ = 0.71073 Å
Tetragonal, P41	Cell parameters from 2729 reflections
Hall symbol: P 4w	θ = 3.0–28.9°
a = 6.7964 (3) Å	µ = 16.14 mm^−1
c = 24.7282 (14) Å	T = 153 K
V = 1142.22 (10) Å^3	Block, green
Z = 4	0.10 × 0.04 × 0.04 mm
F(000) = 1600

Data collection

Bruker SMART 1000 CCD area-detector diffractometer	2729 independent reflections
Radiation source: fine-focus sealed tube	2637 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.034
ω scans	θmax = 28.9°, θmin = 3.0°
Absorption correction: numerical face-indexed using SHELXTL (Sheldrick, 2003)	h = −9→9
Tmin = 0.482, Tmax = 0.741	k = −8→9
10648 measured reflections	l = −31→31

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.024	w = 1/[σ^2(Fo^2) + (0.028P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.055	(Δ/σ)max = 0.001
S = 1.15	Δρmax = 2.40 e Å^−3
2729 reflections	Δρmin = −1.19 e Å^−3
200 parameters	Absolute structure: Flack (1983), with 1284 Friedel pairs
1 restraint	Absolute structure parameter: 0.522 (19)

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.

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

	x	y	z	Uiso*/Ueq
Ce1	0.11721 (6)	0.23463 (6)	0.125617 (17)	0.00974 (10)
Ce2	0.16750 (6)	0.51956 (6)	0.367822 (16)	0.00966 (9)
Ce3	0.33539 (6)	0.08110 (6)	0.265631 (17)	0.00948 (9)
Ce4	0.69879 (6)	0.23761 (6)	0.015776 (17)	0.01020 (10)
Si1	0.2332 (3)	0.1505 (3)	0.00002 (9)	0.0085 (4)
Si2	0.2943 (3)	0.0053 (3)	0.39499 (8)	0.0089 (4)
Si3	0.3784 (3)	0.2598 (3)	0.49333 (9)	0.0086 (4)
Si4	0.5945 (3)	0.3035 (3)	0.15184 (8)	0.0081 (4)
O1	0.0404 (8)	0.1533 (8)	0.2183 (2)	0.0118 (11)
O2	0.0397 (8)	0.4561 (8)	0.5985 (2)	0.0127 (11)
O3	0.0553 (8)	0.2839 (8)	0.0247 (2)	0.0092 (11)
O4	0.1212 (8)	0.5662 (8)	0.1910 (2)	0.0104 (11)
O5	0.1330 (7)	0.1502 (8)	0.3675 (2)	0.0113 (11)
O6	0.1865 (8)	0.2084 (8)	0.6723 (2)	0.0109 (11)
O7	0.2369 (8)	0.4407 (8)	0.4736 (2)	0.0118 (11)
O8	0.2431 (8)	0.1254 (8)	0.5343 (2)	0.0107 (11)
O9	0.3276 (8)	0.4292 (8)	0.2756 (2)	0.0089 (11)
O10	0.3826 (8)	0.1088 (8)	0.0507 (2)	0.0124 (11)
O11	0.4286 (8)	0.1389 (8)	0.1711 (2)	0.0109 (11)
O12	0.4805 (8)	0.4848 (8)	0.1248 (2)	0.0125 (11)
O13	0.7159 (8)	0.3708 (8)	0.2080 (2)	0.0119 (11)
O14	0.7487 (7)	0.1845 (8)	0.1132 (2)	0.0106 (11)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Ce1	0.0097 (2)	0.0101 (2)	0.0094 (2)	0.00114 (15)	−0.00046 (15)	0.00082 (17)
Ce2	0.0095 (2)	0.0096 (2)	0.0099 (2)	−0.00032 (16)	0.00005 (16)	0.00008 (17)
Ce3	0.0098 (2)	0.0096 (2)	0.0090 (2)	0.00112 (16)	−0.00015 (16)	0.00028 (16)
Ce4	0.0092 (2)	0.0110 (2)	0.0104 (2)	−0.00110 (16)	−0.00047 (17)	0.00198 (17)
Si1	0.0096 (10)	0.0071 (10)	0.0090 (10)	−0.0003 (8)	0.0000 (7)	−0.0008 (7)
Si2	0.0097 (10)	0.0100 (10)	0.0070 (10)	0.0003 (8)	0.0009 (8)	0.0006 (8)
Si3	0.0092 (10)	0.0083 (10)	0.0082 (10)	−0.0006 (8)	0.0004 (8)	−0.0015 (8)
Si4	0.0064 (10)	0.0085 (10)	0.0094 (10)	−0.0004 (8)	−0.0005 (8)	−0.0021 (8)
O1	0.019 (3)	0.005 (3)	0.011 (3)	−0.001 (2)	−0.002 (2)	0.001 (2)
O2	0.009 (3)	0.011 (3)	0.018 (3)	−0.003 (2)	0.002 (2)	−0.002 (2)
O3	0.011 (3)	0.007 (3)	0.010 (3)	0.003 (2)	−0.001 (2)	−0.003 (2)
O4	0.011 (3)	0.007 (2)	0.013 (3)	−0.003 (2)	−0.002 (2)	0.002 (2)
O5	0.007 (2)	0.015 (3)	0.012 (3)	0.000 (2)	−0.003 (2)	0.000 (2)
O6	0.010 (3)	0.010 (3)	0.012 (3)	−0.002 (2)	0.000 (2)	−0.001 (2)
O7	0.013 (3)	0.008 (2)	0.015 (3)	−0.005 (2)	0.002 (2)	0.001 (2)
O8	0.011 (3)	0.011 (3)	0.010 (3)	−0.001 (2)	−0.001 (2)	0.003 (2)
O9	0.012 (3)	0.006 (2)	0.008 (3)	−0.005 (2)	0.000 (2)	−0.003 (2)
O10	0.009 (3)	0.013 (3)	0.015 (3)	−0.003 (2)	0.002 (2)	0.000 (2)
O11	0.012 (3)	0.012 (3)	0.009 (3)	−0.002 (2)	0.000 (2)	−0.005 (2)
O12	0.015 (3)	0.016 (3)	0.006 (2)	0.008 (2)	−0.005 (2)	−0.003 (2)
O13	0.012 (3)	0.014 (3)	0.010 (3)	−0.001 (2)	−0.002 (2)	−0.001 (2)
O14	0.008 (3)	0.017 (3)	0.007 (3)	−0.001 (2)	0.001 (2)	−0.003 (2)

Geometric parameters (Å, º)

Ce1—O1	2.414 (5)	Si1—O3	1.630 (5)
Ce1—O2^i	2.450 (6)	Si1—O10	1.638 (6)
Ce1—O11	2.483 (6)	Si1—O13^iv	1.667 (6)
Ce1—O5^ii	2.517 (5)	Si1—Ce3^ii	3.482 (2)
Ce1—O14^iii	2.546 (5)	Si2—O6^ii	1.581 (6)
Ce1—O3	2.553 (5)	Si2—O2^ii	1.619 (6)
Ce1—O10	2.723 (5)	Si2—O5	1.622 (6)
Ce1—O4	2.774 (5)	Si2—O4^v	1.678 (6)
Ce1—Si1	3.255 (2)	Si2—Ce1^v	3.326 (2)
Ce1—Si2^iv	3.326 (2)	Si2—Ce4^xiv	3.413 (2)
Ce1—Si4	3.341 (2)	Si2—Ce2^xv	3.477 (2)
Ce1—Ce2^ii	3.8710 (6)	Si3—O9^v	1.599 (6)
Ce2—O12^v	2.384 (6)	Si3—O7	1.636 (6)
Ce2—O6^iv	2.426 (5)	Si3—O4^v	1.644 (6)
Ce2—O5	2.521 (6)	Si3—O8	1.645 (6)
Ce2—O11^vi	2.541 (5)	Si3—Ce3^vi	3.213 (2)
Ce2—O9	2.601 (5)	Si3—Ce2^v	3.217 (2)
Ce2—O8^iv	2.637 (5)	Si3—Ce4^xiv	3.466 (2)
Ce2—O10^vi	2.673 (5)	Si4—O12	1.602 (6)
Ce2—O7	2.711 (6)	Si4—O14	1.632 (6)
Ce2—O14^vi	2.857 (5)	Si4—O11	1.658 (6)
Ce2—Si3^iv	3.217 (2)	Si4—O13	1.679 (6)
Ce2—Si4^vi	3.348 (2)	Si4—Ce2^ii	3.348 (2)
Ce2—Si2^vii	3.477 (2)	O1—Si1^vi	1.611 (6)
Ce3—O2^ii	2.356 (6)	O2—Si2^vi	1.619 (6)
Ce3—O1	2.373 (6)	O2—Ce3^vi	2.356 (6)
Ce3—O9	2.379 (5)	O2—Ce1^xvi	2.450 (6)
Ce3—O11	2.453 (5)	O3—Ce4^iii	2.453 (5)
Ce3—O7^ii	2.503 (5)	O3—Ce3^iv	2.603 (5)
Ce3—O3^v	2.603 (5)	O4—Si3^iv	1.644 (6)
Ce3—O8^ii	2.666 (6)	O4—Si2^iv	1.678 (6)
Ce3—O5	2.909 (6)	O5—Ce1^vi	2.517 (5)
Ce3—Si3^ii	3.213 (2)	O6—Si2^vi	1.581 (6)
Ce3—Si2	3.252 (2)	O6—Ce4^xvii	2.420 (5)
Ce3—Si1^vi	3.482 (2)	O6—Ce2^v	2.426 (5)
Ce3—Ce4^viii	3.8953 (6)	O7—Ce4^xviii	2.461 (5)
Ce4—O6^ix	2.420 (5)	O7—Ce3^vi	2.503 (5)
Ce4—O3^x	2.453 (5)	O8—Ce4^xiv	2.540 (6)
Ce4—O14	2.459 (6)	O8—Ce2^v	2.637 (5)
Ce4—O7^xi	2.461 (5)	O8—Ce3^vi	2.666 (6)
Ce4—O10	2.476 (5)	O9—Si3^iv	1.599 (6)
Ce4—O8^xii	2.540 (6)	O10—Ce2^ii	2.673 (5)
Ce4—O13^iv	2.667 (5)	O11—Ce2^ii	2.541 (5)
Ce4—Si1	3.243 (2)	O12—Ce2^iv	2.384 (6)
Ce4—Si2^xii	3.413 (2)	O13—Si1^v	1.667 (6)
Ce4—Si3^xii	3.466 (2)	O13—Ce4^v	2.667 (5)
Ce4—Si4	3.467 (2)	O14—Ce1^x	2.546 (5)
Ce4—Ce3^xiii	3.8953 (6)	O14—Ce2^ii	2.857 (5)
Si1—O1^ii	1.611 (6)
O1—Ce1—O2^i	111.20 (19)	O3^x—Ce4—O10	150.58 (18)
O1—Ce1—O11	72.20 (19)	O14—Ce4—O10	74.08 (17)
O2^i—Ce1—O11	136.00 (17)	O7^xi—Ce4—O10	128.02 (18)
O1—Ce1—O5^ii	82.38 (18)	O6^ix—Ce4—O8^xii	89.55 (17)
O2^i—Ce1—O5^ii	150.32 (18)	O3^x—Ce4—O8^xii	87.42 (17)
O11—Ce1—O5^ii	72.54 (17)	O14—Ce4—O8^xii	70.10 (17)
O1—Ce1—O14^iii	82.61 (19)	O7^xi—Ce4—O8^xii	155.70 (19)
O2^i—Ce1—O14^iii	69.74 (17)	O10—Ce4—O8^xii	74.26 (18)
O11—Ce1—O14^iii	149.08 (19)	O6^ix—Ce4—O13^iv	73.95 (18)
O5^ii—Ce1—O14^iii	86.86 (17)	O3^x—Ce4—O13^iv	149.17 (17)
O1—Ce1—O3	157.26 (18)	O14—Ce4—O13^iv	131.10 (17)
O2^i—Ce1—O3	63.16 (18)	O7^xi—Ce4—O13^iv	79.41 (17)
O11—Ce1—O3	128.15 (17)	O10—Ce4—O13^iv	60.22 (17)
O5^ii—Ce1—O3	93.87 (17)	O8^xii—Ce4—O13^iv	109.97 (17)
O14^iii—Ce1—O3	74.77 (17)	O6^ix—Ce4—Si1	96.52 (14)
O1—Ce1—O10	135.79 (18)	O3^x—Ce4—Si1	176.37 (13)
O2^i—Ce1—O10	111.83 (17)	O14—Ce4—Si1	103.03 (12)
O11—Ce1—O10	70.20 (17)	O7^xi—Ce4—Si1	106.53 (13)
O5^ii—Ce1—O10	64.86 (17)	O10—Ce4—Si1	29.60 (13)
O14^iii—Ce1—O10	121.84 (17)	O8^xii—Ce4—Si1	89.76 (13)
O3—Ce1—O10	59.05 (17)	O13^iv—Ce4—Si1	30.85 (12)
O1—Ce1—O4	68.58 (16)	O6^ix—Ce4—Si2^xii	24.71 (14)
O2^i—Ce1—O4	57.77 (18)	O3^x—Ce4—Si2^xii	97.30 (12)
O11—Ce1—O4	86.58 (16)	O14—Ce4—Si2^xii	141.66 (13)
O5^ii—Ce1—O4	148.43 (18)	O7^xi—Ce4—Si2^xii	93.23 (14)
O14^iii—Ce1—O4	100.88 (16)	O10—Ce4—Si2^xii	98.43 (13)
O3—Ce1—O4	117.70 (16)	O8^xii—Ce4—Si2^xii	71.67 (12)
O10—Ce1—O4	130.17 (15)	O13^iv—Ce4—Si2^xii	66.43 (12)
O1—Ce1—Si1	156.61 (13)	Si1—Ce4—Si2^xii	79.63 (5)
O2^i—Ce1—Si1	89.74 (14)	O6^ix—Ce4—Si3^xii	75.33 (14)
O11—Ce1—Si1	100.36 (13)	O3^x—Ce4—Si3^xii	106.80 (12)
O5^ii—Ce1—Si1	74.23 (13)	O14—Ce4—Si3^xii	91.99 (13)
O14^iii—Ce1—Si1	95.71 (13)	O7^xi—Ce4—Si3^xii	145.63 (14)
O3—Ce1—Si1	29.57 (12)	O10—Ce4—Si3^xii	65.15 (13)
O10—Ce1—Si1	30.17 (12)	O8^xii—Ce4—Si3^xii	26.49 (13)
O4—Ce1—Si1	134.16 (12)	O13^iv—Ce4—Si3^xii	84.45 (12)
O1—Ce1—Si2^iv	91.96 (13)	Si1—Ce4—Si3^xii	69.81 (5)
O2^i—Ce1—Si2^iv	27.62 (13)	Si2^xii—Ce4—Si3^xii	52.42 (5)
O11—Ce1—Si2^iv	112.45 (13)	O6^ix—Ce4—Si4	176.55 (14)
O5^ii—Ce1—Si2^iv	171.01 (13)	O3^x—Ce4—Si4	95.63 (13)
O14^iii—Ce1—Si2^iv	85.48 (13)	O14—Ce4—Si4	25.40 (13)
O3—Ce1—Si2^iv	88.67 (12)	O7^xi—Ce4—Si4	109.44 (14)
O10—Ce1—Si2^iv	123.49 (12)	O10—Ce4—Si4	61.93 (13)
O4—Ce1—Si2^iv	30.24 (12)	O8^xii—Ce4—Si4	88.99 (12)
Si1—Ce1—Si2^iv	111.23 (5)	O13^iv—Ce4—Si4	109.49 (12)
O1—Ce1—Si4	93.31 (14)	Si1—Ce4—Si4	86.60 (5)
O2^i—Ce1—Si4	110.82 (13)	Si2^xii—Ce4—Si4	156.12 (5)
O11—Ce1—Si4	28.52 (13)	Si3^xii—Ce4—Si4	104.50 (5)
O5^ii—Ce1—Si4	93.89 (13)	O6^ix—Ce4—Ce3^xiii	86.10 (13)
O14^iii—Ce1—Si4	175.72 (13)	O3^x—Ce4—Ce3^xiii	41.04 (12)
O3—Ce1—Si4	109.35 (12)	O14—Ce4—Ce3^xiii	91.04 (12)
O10—Ce1—Si4	62.14 (12)	O7^xi—Ce4—Ce3^xiii	38.69 (13)
O4—Ce1—Si4	76.33 (11)	O10—Ce4—Ce3^xiii	147.41 (13)
Si1—Ce1—Si4	88.54 (6)	O8^xii—Ce4—Ce3^xiii	128.33 (12)
Si2^iv—Ce1—Si4	93.40 (5)	O13^iv—Ce4—Ce3^xiii	117.96 (12)
O1—Ce1—Ce2^ii	92.20 (14)	Si1—Ce4—Ce3^xiii	141.89 (4)
O2^i—Ce1—Ce2^ii	154.09 (13)	Si2^xii—Ce4—Ce3^xiii	110.51 (4)
O11—Ce1—Ce2^ii	40.15 (12)	Si3^xii—Ce4—Ce3^xiii	145.85 (4)
O5^ii—Ce1—Ce2^ii	39.84 (12)	Si4—Ce4—Ce3^xiii	92.35 (4)
O14^iii—Ce1—Ce2^ii	126.47 (12)	O1^ii—Si1—O3	112.4 (3)
O3—Ce1—Ce2^ii	99.23 (11)	O1^ii—Si1—O10	116.3 (3)
O10—Ce1—Ce2^ii	43.65 (12)	O3—Si1—O10	105.6 (3)
O4—Ce1—Ce2^ii	126.56 (11)	O1^ii—Si1—O13^iv	108.9 (3)
Si1—Ce1—Ce2^ii	69.96 (4)	O3—Si1—O13^iv	110.2 (3)
Si2^iv—Ce1—Ce2^ii	148.05 (4)	O10—Si1—O13^iv	102.9 (3)
Si4—Ce1—Ce2^ii	54.73 (4)	O1^ii—Si1—Ce4	122.3 (2)
O12^v—Ce2—O6^iv	86.43 (18)	O3—Si1—Ce4	125.3 (2)
O12^v—Ce2—O5	88.93 (17)	O10—Si1—Ce4	48.3 (2)
O6^iv—Ce2—O5	146.31 (18)	O13^iv—Si1—Ce4	55.1 (2)
O12^v—Ce2—O11^vi	138.36 (18)	O1^ii—Si1—Ce1	121.7 (2)
O6^iv—Ce2—O11^vi	90.34 (18)	O3—Si1—Ce1	50.6 (2)
O5—Ce2—O11^vi	71.52 (17)	O10—Si1—Ce1	56.6 (2)
O12^v—Ce2—O9	67.85 (17)	O13^iv—Si1—Ce1	129.4 (2)
O6^iv—Ce2—O9	129.34 (18)	Ce4—Si1—Ce1	95.14 (6)
O5—Ce2—O9	78.55 (17)	O3—Si1—Ce3^ii	105.4 (2)
O11^vi—Ce2—O9	137.77 (17)	O10—Si1—Ce3^ii	86.3 (2)
O12^v—Ce2—O8^iv	103.47 (18)	O13^iv—Si1—Ce3^ii	138.8 (2)
O6^iv—Ce2—O8^iv	86.80 (18)	Ce4—Si1—Ce3^ii	116.72 (6)
O5—Ce2—O8^iv	126.64 (18)	Ce1—Si1—Ce3^ii	89.37 (5)
O11^vi—Ce2—O8^iv	117.79 (17)	O6^ii—Si2—O2^ii	113.5 (3)
O9—Ce2—O8^iv	60.17 (17)	O6^ii—Si2—O5	115.5 (3)
O12^v—Ce2—O10^vi	134.65 (17)	O2^ii—Si2—O5	106.1 (3)
O6^iv—Ce2—O10^vi	135.40 (18)	O6^ii—Si2—O4^v	107.8 (3)
O5—Ce2—O10^vi	65.56 (16)	O2^ii—Si2—O4^v	100.7 (3)
O11^vi—Ce2—O10^vi	70.20 (18)	O5—Si2—O4^v	112.4 (3)
O9—Ce2—O10^vi	70.58 (16)	O6^ii—Si2—Ce3	125.7 (2)
O8^iv—Ce2—O10^vi	69.54 (17)	O5—Si2—Ce3	63.3 (2)
O12^v—Ce2—O7	74.64 (17)	O4^v—Si2—Ce3	123.0 (2)
O6^iv—Ce2—O7	66.84 (17)	O6^ii—Si2—Ce1^v	127.3 (2)
O5—Ce2—O7	79.75 (17)	O5—Si2—Ce1^v	116.8 (2)
O11^vi—Ce2—O7	66.06 (17)	O4^v—Si2—Ce1^v	56.4 (2)
O9—Ce2—O7	136.61 (18)	Ce3—Si2—Ce1^v	74.89 (5)
O8^iv—Ce2—O7	153.61 (16)	O2^ii—Si2—Ce4^xiv	121.3 (2)
O10^vi—Ce2—O7	130.70 (16)	O5—Si2—Ce4^xiv	132.0 (2)
O12^v—Ce2—O14^vi	153.34 (17)	O4^v—Si2—Ce4^xiv	68.0 (2)
O6^iv—Ce2—O14^vi	70.69 (16)	Ce3—Si2—Ce4^xiv	159.43 (7)
O5—Ce2—O14^vi	117.70 (16)	Ce1^v—Si2—Ce4^xiv	102.91 (6)
O11^vi—Ce2—O14^vi	57.80 (16)	O2^ii—Si2—Ce2^xv	81.5 (2)
O9—Ce2—O14^vi	116.35 (16)	O5—Si2—Ce2^xv	109.2 (2)
O8^iv—Ce2—O14^vi	62.88 (16)	O4^v—Si2—Ce2^xv	135.8 (2)
O10^vi—Ce2—O14^vi	64.95 (16)	Ce3—Si2—Ce2^xv	88.95 (5)
O7—Ce2—O14^vi	106.99 (17)	Ce1^v—Si2—Ce2^xv	115.33 (6)
O12^v—Ce2—Si3^iv	84.29 (13)	Ce4^xiv—Si2—Ce2^xv	73.34 (4)
O6^iv—Ce2—Si3^iv	109.39 (14)	O9^v—Si3—O7	114.4 (3)
O5—Ce2—Si3^iv	103.30 (14)	O9^v—Si3—O4^v	111.7 (3)
O11^vi—Ce2—Si3^iv	135.11 (13)	O7—Si3—O4^v	109.3 (3)
O9—Ce2—Si3^iv	29.55 (13)	O9^v—Si3—O8	108.1 (3)
O8^iv—Ce2—Si3^iv	30.63 (12)	O7—Si3—O8	105.8 (3)
O10^vi—Ce2—Si3^iv	67.56 (12)	O4^v—Si3—O8	107.1 (3)
O7—Ce2—Si3^iv	158.71 (12)	O9^v—Si3—Ce3^vi	131.5 (2)
O14^vi—Ce2—Si3^iv	90.42 (12)	O7—Si3—Ce3^vi	50.16 (19)
O12^v—Ce2—Si4^vi	161.09 (13)	O4^v—Si3—Ce3^vi	116.7 (2)
O6^iv—Ce2—Si4^vi	81.06 (14)	O8—Si3—Ce3^vi	55.9 (2)
O5—Ce2—Si4^vi	93.63 (12)	O9^v—Si3—Ce2^v	53.4 (2)
O11^vi—Ce2—Si4^vi	28.75 (13)	O7—Si3—Ce2^v	124.0 (2)
O9—Ce2—Si4^vi	131.01 (12)	O4^v—Si3—Ce2^v	126.3 (2)
O8^iv—Ce2—Si4^vi	90.00 (12)	O8—Si3—Ce2^v	54.78 (19)
O10^vi—Ce2—Si4^vi	62.43 (12)	Ce3^vi—Si3—Ce2^v	94.38 (6)
O7—Ce2—Si4^vi	87.37 (12)	O9^v—Si3—Ce4^xiv	109.0 (2)
O14^vi—Ce2—Si4^vi	29.15 (11)	O7—Si3—Ce4^xiv	133.8 (2)
Si3^iv—Ce2—Si4^vi	113.20 (5)	O4^v—Si3—Ce4^xiv	66.5 (2)
O12^v—Ce2—Si2^vii	81.15 (14)	Ce3^vi—Si3—Ce4^xiv	88.93 (5)
O6^iv—Ce2—Si2^vii	23.44 (13)	Ce2^v—Si3—Ce4^xiv	71.89 (4)
O5—Ce2—Si2^vii	165.65 (13)	O12—Si4—O14	116.6 (3)
O11^vi—Ce2—Si2^vii	109.51 (13)	O12—Si4—O11	108.0 (3)
O9—Ce2—Si2^vii	106.85 (12)	O14—Si4—O11	105.7 (3)
O8^iv—Ce2—Si2^vii	66.27 (13)	O12—Si4—O13	111.9 (3)
O10^vi—Ce2—Si2^vii	128.65 (12)	O14—Si4—O13	107.7 (3)
O7—Ce2—Si2^vii	87.60 (12)	O11—Si4—O13	106.3 (3)
O14^vi—Ce2—Si2^vii	72.41 (12)	O12—Si4—Ce1	63.7 (2)
Si3^iv—Ce2—Si2^vii	86.10 (5)	O14—Si4—Ce1	116.1 (2)
Si4^vi—Ce2—Si2^vii	92.52 (5)	O11—Si4—Ce1	45.7 (2)
O2^ii—Ce3—O1	142.72 (19)	O13—Si4—Ce1	132.5 (2)
O2^ii—Ce3—O9	105.33 (18)	O12—Si4—Ce2^ii	123.9 (2)
O1—Ce3—O9	80.01 (18)	O14—Si4—Ce2^ii	58.5 (2)
O2^ii—Ce3—O11	142.66 (19)	O11—Si4—Ce2^ii	47.47 (19)
O1—Ce3—O11	73.43 (19)	O13—Si4—Ce2^ii	122.9 (2)
O9—Ce3—O11	86.83 (18)	Ce1—Si4—Ce2^ii	70.71 (4)
O2^ii—Ce3—O7^ii	87.76 (18)	O12—Si4—Ce4	78.1 (2)
O1—Ce3—O7^ii	102.43 (18)	O11—Si4—Ce4	109.3 (2)
O9—Ce3—O7^ii	155.22 (19)	O13—Si4—Ce4	137.5 (2)
O11—Ce3—O7^ii	70.66 (18)	Ce1—Si4—Ce4	89.55 (5)
O2^ii—Ce3—O3^v	63.60 (17)	Ce2^ii—Si4—Ce4	70.36 (4)
O1—Ce3—O3^v	153.66 (18)	Si1^vi—O1—Ce3	120.6 (3)
O9—Ce3—O3^v	94.60 (17)	Si1^vi—O1—Ce1	124.0 (3)
O11—Ce3—O3^v	80.57 (17)	Ce3—O1—Ce1	109.5 (2)
O7^ii—Ce3—O3^v	72.14 (17)	Si2^vi—O2—Ce3^vi	108.4 (3)
O2^ii—Ce3—O8^ii	75.40 (18)	Si2^vi—O2—Ce1^xvi	107.8 (3)
O1—Ce3—O8^ii	78.69 (17)	Ce3^vi—O2—Ce1^xvi	112.6 (2)
O9—Ce3—O8^ii	142.40 (17)	Si1—O3—Ce4^iii	128.9 (3)
O11—Ce3—O8^ii	115.81 (17)	Si1—O3—Ce1	99.8 (2)
O7^ii—Ce3—O8^ii	60.73 (18)	Ce4^iii—O3—Ce1	103.53 (19)
O3^v—Ce3—O8^ii	117.50 (16)	Si1—O3—Ce3^iv	118.1 (3)
O2^ii—Ce3—O5	57.79 (17)	Ce4^iii—O3—Ce3^iv	100.74 (18)
O1—Ce3—O5	89.70 (17)	Ce1—O3—Ce3^iv	101.74 (18)
O9—Ce3—O5	74.91 (16)	Si3^iv—O4—Si2^iv	132.3 (4)
O11—Ce3—O5	157.15 (17)	Si3^iv—O4—Ce1	130.6 (3)
O7^ii—Ce3—O5	129.37 (17)	Si2^iv—O4—Ce1	93.4 (2)
O3^v—Ce3—O5	113.96 (16)	Si2—O5—Ce1^vi	125.7 (3)
O8^ii—Ce3—O5	74.37 (16)	Si2—O5—Ce2	122.7 (3)
O2^ii—Ce3—Si3^ii	82.32 (14)	Ce1^vi—O5—Ce2	100.41 (18)
O1—Ce3—Si3^ii	88.93 (13)	Si2—O5—Ce3	86.9 (2)
O9—Ce3—Si3^ii	168.76 (13)	Ce1^vi—O5—Ce3	121.6 (2)
O11—Ce3—Si3^ii	91.92 (13)	Ce2—O5—Ce3	96.84 (18)
O7^ii—Ce3—Si3^ii	30.12 (13)	Si2^vi—O6—Ce4^xvii	115.5 (3)
O3^v—Ce3—Si3^ii	96.21 (12)	Si2^vi—O6—Ce2^v	118.9 (3)
O8^ii—Ce3—Si3^ii	30.73 (12)	Ce4^xvii—O6—Ce2^v	116.3 (2)
O5—Ce3—Si3^ii	103.30 (12)	Si3—O7—Ce4^xviii	115.9 (3)
O2^ii—Ce3—Si2	28.20 (14)	Si3—O7—Ce3^vi	99.7 (2)
O1—Ce3—Si2	116.46 (14)	Ce4^xviii—O7—Ce3^vi	103.4 (2)
O9—Ce3—Si2	93.10 (13)	Si3—O7—Ce2	122.6 (3)
O11—Ce3—Si2	169.96 (13)	Ce4^xviii—O7—Ce2	105.31 (19)
O7^ii—Ce3—Si2	107.23 (14)	Ce3^vi—O7—Ce2	107.9 (2)
O3^v—Ce3—Si2	89.43 (12)	Si3—O8—Ce4^xiv	110.0 (3)
O8^ii—Ce3—Si2	69.70 (12)	Si3—O8—Ce2^v	94.6 (2)
O5—Ce3—Si2	29.87 (11)	Ce4^xiv—O8—Ce2^v	98.72 (18)
Si3^ii—Ce3—Si2	90.07 (5)	Si3—O8—Ce3^vi	93.3 (2)
O2^ii—Ce3—Si1^vi	122.02 (14)	Ce4^xiv—O8—Ce3^vi	128.1 (2)
O1—Ce3—Si1^vi	23.46 (14)	Ce2^v—O8—Ce3^vi	125.7 (2)
O9—Ce3—Si1^vi	72.25 (13)	Si3^iv—O9—Ce3	140.2 (3)
O11—Ce3—Si1^vi	95.26 (13)	Si3^iv—O9—Ce2	97.1 (2)
O7^ii—Ce3—Si1^vi	118.79 (13)	Ce3—O9—Ce2	109.54 (19)
O3^v—Ce3—Si1^vi	166.49 (12)	Si1—O10—Ce4	102.1 (3)
O8^ii—Ce3—Si1^vi	75.92 (12)	Si1—O10—Ce2^ii	144.3 (3)
O5—Ce3—Si1^vi	66.40 (11)	Ce4—O10—Ce2^ii	99.37 (18)
Si3^ii—Ce3—Si1^vi	96.77 (5)	Si1—O10—Ce1	93.2 (2)
Si2—Ce3—Si1^vi	94.28 (5)	Ce4—O10—Ce1	134.5 (2)
O2^ii—Ce3—Ce4^viii	60.48 (13)	Ce2^ii—O10—Ce1	91.68 (17)
O1—Ce3—Ce4^viii	140.16 (13)	Si4—O11—Ce3	123.9 (3)
O9—Ce3—Ce4^viii	132.82 (13)	Si4—O11—Ce1	105.8 (3)
O11—Ce3—Ce4^viii	85.14 (13)	Ce3—O11—Ce1	104.7 (2)
O7^ii—Ce3—Ce4^viii	37.93 (12)	Si4—O11—Ce2^ii	103.8 (3)
O3^v—Ce3—Ce4^viii	38.22 (12)	Ce3—O11—Ce2^ii	115.2 (2)
O8^ii—Ce3—Ce4^viii	81.22 (12)	Ce1—O11—Ce2^ii	100.78 (18)
O5—Ce3—Ce4^viii	117.33 (10)	Si4—O12—Ce2^iv	137.7 (3)
Si3^ii—Ce3—Ce4^viii	58.05 (4)	Si1^v—O13—Si4	129.1 (3)
Si2—Ce3—Ce4^viii	87.56 (4)	Si1^v—O13—Ce4^v	94.0 (2)
Si1^vi—Ce3—Ce4^viii	154.79 (4)	Si4—O13—Ce4^v	136.8 (3)
O6^ix—Ce4—O3^x	81.19 (18)	Si4—O14—Ce4	114.4 (3)
O6^ix—Ce4—O14	151.42 (17)	Si4—O14—Ce1^x	119.6 (3)
O3^x—Ce4—O14	78.14 (17)	Ce4—O14—Ce1^x	103.55 (19)
O6^ix—Ce4—O7^xi	71.13 (19)	Si4—O14—Ce2^ii	92.4 (2)
O3^x—Ce4—O7^xi	75.46 (18)	Ce4—O14—Ce2^ii	94.99 (17)
O14—Ce4—O7^xi	121.39 (18)	Ce1^x—O14—Ce2^ii	130.0 (2)
O6^ix—Ce4—O10	120.60 (19)

Symmetry codes: (i) −x, −y+1, z−1/2; (ii) y, −x, z−1/4; (iii) x−1, y, z; (iv) y, −x+1, z−1/4; (v) −y+1, x, z+1/4; (vi) −y, x, z+1/4; (vii) x, y+1, z; (viii) −y+1, x−1, z+1/4; (ix) −y+1, x, z−3/4; (x) x+1, y, z; (xi) −x+1, −y+1, z−1/2; (xii) −x+1, −y, z−1/2; (xiii) y+1, −x+1, z−1/4; (xiv) −x+1, −y, z+1/2; (xv) x, y−1, z; (xvi) −x, −y+1, z+1/2; (xvii) y, −x+1, z+3/4; (xviii) −x+1, −y+1, z+1/2.