Cs₃Sm₇Se₁₂

The title compound, tricaesium hepta­samarium(III) dodeca­selenide, is setting a new starting point for realization of the channel structure of the Cs₃M₇Se₁₂ series, now with M = Sm, Gd-Er. This Cs₃Y₇Se₁₂-type arrangement is structurally based on the Z-type sesquiselenides M₂Se₃ adopting the Sc₂S₃ structure. Thus, the structural set-up of Cs₃Sm₇Se₁₂ consists of edge- and vertex-connected [SmSe₆]^9- octa­hedra [d_Ø(Sm³⁺ - Se^2-) = 2.931 Å], forming a rock-salt-related network [Sm₇Se₁₂]^3- with channels along [001] that are apt to take up monovalent cations (here Cs⁺) with coordination numbers of 7 + 1 for one and of 6 for the second cation. The latter cation has a trigonal-prismatic coordination and shows half-occupancy, resulting in an impossible short distance [2.394 (4) Å] between symmetrically coupled Cs⁺ cations of the same kind. While one Sm atom occupies Wyckoff position 2b with site symmetry ..2/m, all other 11 crystallographically different atoms (namely 2 × Cs, 3 × Sm and 6 × Se) are located at Wyckoff positions 4g with site symmetry ..m.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](Sm-Se) = 0.001 Å
• Disorder in solvent or counterion
• R factor = 0.035
• wR factor = 0.072
• Data-to-parameter ratio = 29.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT774_ALERT_1_B Suspect X-Y Bond in CIF:   CS1    --  SE1     ..       4.54 Ang.
PLAT774_ALERT_1_B Suspect X-Y Bond in CIF:   CS1    --  CS1     ..       4.24 Ang.
PLAT774_ALERT_1_B Suspect X-Y Bond in CIF:   CS1    --  CS1     ..       4.24 Ang.
PLAT774_ALERT_1_B Suspect X-Y Bond in CIF:   CS2    --  SM2     ..       4.16 Ang.

Alert level C
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......      0.967
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS1    --  SE4     ..       3.61 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS1    --  SE4     ..       3.61 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS1    --  SE6     ..       3.71 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS1    --  SE6     ..       3.71 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS1    --  SE3     ..       3.76 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS1    --  SE5     ..       3.81 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS1    --  SE5     ..       3.81 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS2    --  SE2     ..       3.53 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS2    --  SE2     ..       3.53 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS2    --  SE2     ..       3.69 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS2    --  SE2     ..       3.69 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS2    --  SE5     ..       3.72 Ang.
PLAT774_ALERT_1_C Suspect X-Y Bond in CIF:   CS2    --  SE6     ..       3.92 Ang.
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          3
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         30
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         39
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....          1
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       2.36 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       2.27 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       2.27 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       2.12 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.93 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.80 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.79 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.79 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.79 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.76 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.73 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.68 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.64 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.60 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -2.11 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.69 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.66 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.64 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.59 eA-3

Alert level G
PLAT004_ALERT_5_G Info: Polymeric Structure Found with Dimension .          1
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K
PLAT302_ALERT_4_G Note: Anion/Solvent Disorder ...................         33 Perc.
PLAT794_ALERT_5_G Note: Tentative Bond Valency for Sm1     (III)         3.02
PLAT794_ALERT_5_G Note: Tentative Bond Valency for Sm2     (III)         3.00
PLAT794_ALERT_5_G Note: Tentative Bond Valency for Sm3     (III)         3.00
PLAT794_ALERT_5_G Note: Tentative Bond Valency for Sm4     (III)         2.98
PLAT961_ALERT_5_G Dataset Contains no Negative Intensities .......          !

   0 ALERT level A = Most likely a serious problem - resolve or explain
   4 ALERT level B = A potentially serious problem, consider carefully
  37 ALERT level C = Check. Ensure it is not caused by an omission or oversight
  10 ALERT level G = General information/check it is not something unexpected

  19 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
  19 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   7 ALERT type 5 Informative message, check

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S1. Comment

Cs₃Sm₇Se₁₂ crystallizes isotypically to the large family of ternary A₃M₇Ch₁₂ representatives with a channel-like structure. For Ch = S, A = K, Rb, M = Er, see: Lissner et al. (2002); for Ch = Se, A = Rb, M = Dy, Yb, see: Folchnandt & Schleid (2000), Kim et al. (1996); for Ch = Se, A = Cs, M = Y, Gd – Er, see: Folchnandt & Schleid (1996, 1997, 1998); for Ch = Te, A = Cs, M = Sm, Gd, Tb, see: Tougaît et al. (2001).

In the title compound, [SmSe₆]^9- octahedra (d(Sm³⁺–Se^2-) = 2.8578 (9)–3.0614 (13) Å) are connected via edges and corners to form a [Sm₇Se₁₂]^3- network with triple-channels occupied by Cs⁺ cations (Fig. 1). This network represents a defect rock-salt-type structure strongly related to that of the Z-type sesquiselenides M₂Se₃ (Dismukes & White, 1964) according to the formula [□]₄[M]₈[Se]₁₂. In tricaesium heptasamarium(III) dodecaselenide three Cs⁺ cations replace one Sm³⁺ for charge balance. The triple-channels are arranged in a herringbone pattern and run through the structure parallel to [001]. They are filled with two crystallographically different Cs⁺ cations (Fig. 2). While Cs1⁺ exhibits a coordination number of 7+1 with an extra secondary contact (d(Cs1⁺–Se^2-) = 3.6071 (12)–3.8053 (12) Å and 4.5421 (14) Å; Fig. 2, left), the Cs2⁺ cations have only six selenide anions as nearest neighbours in the shape of a trigonal prism (d(Cs2⁺–Se^2-) = 3.5286 (16) – 3.924 (2) Å; Fig. 2, right). Owing to the very close distances between these Cs2⁺ cations (d(Cs2⁺···Cs2⁺) = 2.394 (4) Å) only a half-occupation of this position is possible (Fig. 2, right and Fig. 3) and stoichiometrically meaningful.

Related literature

For prototypic Cs₃Y₇Se₁₂ or Rb₃Yb₇Se₁₂, see: Folchnandt & Schleid (1996); Kim et al. (1996). For other representatives of the A₃M₇Ch₁₂ series, see: Folchnandt & Schleid (1997, 1998, 2000); Tougaît et al. (2001); Lissner et al. (2002). A detailed description of the relation between the crystal structures of the Cs₃M₇Se₁₂ series and Z-type Sc₂Ch₃ (Dismukes & White, 1964) is provided by Folchnandt & Schleid (1998).

S2. Experimental

Yellow, transparent, needle-shaped single crystals of Cs₃Sm₇Se₁₂ were obtained as the main product of a reaction between 0.10 g Sm, 0.08 g Se and 0.50 g CsCl added as flux and caesium source upon heating at 1073 K for 10 days in a sealed, evacuated fused-silica vessel.

S3. Refinement

In the final difference Fourier map the highest peak is 1.24 Å away from Se2 and the deepest hole is located 0.83 Å away from Sm2.

Computing details

Data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4 (Stoe & Cie, 1992); data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2006); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures

	Fig. 1. Channel-structure representation of Cs3Sm7Se12 as octahedral framework with indicated unit cell.
	Fig. 2. Coordination spheres of the Cs1^+ (left) and Cs2^+ (right) cations in Cs3Sm7Se12. Displacement ellipsoids are drawn at the 90% probability level. Symmetry codes: (i) -x+1/2, y-1/2, z+1/2; (ii) -x+1/2, y-1/2, z-1/2; (iii) -x+1, -y+1, -z; (viii) -x+1, -y, -z; (ix) x+1/2, -y+1/2, -z-1/2; (x) x+1/2, -y+1/2, -z+1/2.
	Fig. 3. Interplay of the Cs^+ cations situated in the triple-channels of the crystal structure of Cs3Sm7Se12. Displacement ellipsoids are drawn at the 90% probability level.

tricaesium heptasamarium(III) dodecaselenide

Crystal data

Cs3Sm7Se12	F(000) = 2014
Mr = 2398.70	Dx = 5.408 Mg m^−3
Orthorhombic, Pnnm	Mo Kα radiation, λ = 0.71069 Å
Hall symbol: -P 2 2n	Cell parameters from 5000 reflections
a = 13.0387 (9) Å	θ = 2.1–29.3°
b = 26.6742 (19) Å	µ = 32.19 mm^−1
c = 4.2351 (3) Å	T = 293 K
V = 1472.95 (18) Å^3	Needle, yellow
Z = 2	0.10 × 0.07 × 0.05 mm

Data collection

Stoe IPDS-I diffractometer	2135 independent reflections
Radiation source: fine-focus sealed tube	1587 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.065
imaging plate detector system scans	θmax = 29.0°, θmin = 2.8°
Absorption correction: numerical (X-SHAPE; Stoe & Cie, 1999)	h = −17→17
Tmin = 0.115, Tmax = 0.216	k = −36→36
15080 measured reflections	l = −5→5

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)] = 0.035	w = 1/[σ^2(Fo^2) + (0.0371P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.072	(Δ/σ)max = 0.014
S = 0.97	Δρmax = 2.09 e Å^−3
2135 reflections	Δρmin = −1.78 e Å^−3
72 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.00017 (4)

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2sigma(F²) 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 (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
Cs1	0.28796 (6)	0.36600 (3)	0.0000	0.0252 (2)
Cs2	0.56532 (14)	0.03154 (7)	0.0000	0.0311 (5)	0.50
Sm1	0.0000	0.0000	0.5000	0.0124 (2)
Sm2	0.21848 (5)	0.08314 (2)	0.0000	0.01316 (15)
Sm3	0.40590 (4)	0.71214 (2)	0.0000	0.01224 (15)
Sm4	0.07792 (5)	0.68240 (2)	0.0000	0.01271 (15)
Se1	0.25592 (8)	0.19644 (4)	0.0000	0.0125 (3)
Se2	0.12980 (9)	0.57736 (4)	0.0000	0.0142 (3)
Se3	0.43019 (9)	0.60350 (4)	0.0000	0.0129 (3)
Se4	0.05307 (8)	0.78890 (4)	0.0000	0.0133 (3)
Se5	0.15051 (9)	0.98065 (4)	0.0000	0.0142 (3)
Se6	0.42742 (9)	0.82140 (4)	0.0000	0.0133 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cs1	0.0214 (4)	0.0295 (4)	0.0247 (6)	−0.0002 (3)	0.000	0.000
Cs2	0.0266 (9)	0.0273 (9)	0.0393 (14)	0.0114 (7)	0.000	0.000
Sm1	0.0147 (4)	0.0109 (4)	0.0116 (6)	−0.0030 (3)	0.000	0.000
Sm2	0.0153 (3)	0.0135 (3)	0.0107 (4)	−0.0027 (2)	0.000	0.000
Sm3	0.0137 (3)	0.0117 (3)	0.0113 (4)	−0.0018 (2)	0.000	0.000
Sm4	0.0131 (3)	0.0130 (3)	0.0121 (4)	0.0034 (2)	0.000	0.000
Se1	0.0123 (5)	0.0153 (5)	0.0101 (7)	−0.0004 (4)	0.000	0.000
Se2	0.0147 (6)	0.0142 (5)	0.0137 (8)	0.0007 (4)	0.000	0.000
Se3	0.0154 (5)	0.0096 (5)	0.0138 (7)	0.0007 (4)	0.000	0.000
Se4	0.0144 (5)	0.0128 (5)	0.0126 (8)	0.0000 (4)	0.000	0.000
Se5	0.0155 (5)	0.0129 (5)	0.0141 (8)	−0.0004 (4)	0.000	0.000
Se6	0.0140 (5)	0.0134 (5)	0.0124 (8)	0.0008 (4)	0.000	0.000

Geometric parameters (Å, º)

Cs1—Se4^i	3.6071 (12)	Sm1—Se5^xi	2.9328 (8)
Cs1—Se4^ii	3.6071 (12)	Sm1—Se5^xii	2.9328 (8)
Cs1—Se6^ii	3.7129 (12)	Sm1—Se5^xiii	2.9328 (8)
Cs1—Se6^i	3.7129 (12)	Sm2—Se5^xiii	2.8738 (13)
Cs1—Se3^iii	3.7639 (14)	Sm2—Se2^i	2.9020 (10)
Cs1—Se5^i	3.8053 (12)	Sm2—Se2^ii	2.9020 (10)
Cs1—Se5^ii	3.8053 (12)	Sm2—Se3^ii	2.9217 (9)
Cs1—Se1	4.5421 (14)	Sm2—Se3^i	2.9217 (9)
Cs1—Cs1^iv	4.2351 (3)	Sm2—Se1	3.0614 (13)
Cs1—Cs1^v	4.2351 (3)	Sm3—Se4^xiv	2.8578 (9)
Cs2—Cs2^vi	2.394 (4)	Sm3—Se4^xv	2.8578 (9)
Cs2—Se2^ii	3.5286 (16)	Sm3—Se3	2.9152 (13)
Cs2—Se2^i	3.5286 (16)	Sm3—Se6	2.9279 (13)
Cs2—Se2^vii	3.6917 (17)	Sm3—Se1^xvi	3.0185 (9)
Cs2—Se2^viii	3.6917 (17)	Sm3—Se1^xvii	3.0185 (9)
Cs2—Se5^iii	3.719 (2)	Sm4—Se4	2.8591 (13)
Cs2—Se6^iii	3.924 (2)	Sm4—Se2	2.8823 (13)
Cs2—Sm2^vi	4.1597 (18)	Sm4—Se6^xviii	2.8888 (9)
Sm1—Se3^i	2.9070 (11)	Sm4—Se6^xix	2.8888 (9)
Sm1—Se3^ix	2.9070 (11)	Sm4—Se1^xvii	3.0526 (9)
Sm1—Se5^x	2.9328 (8)	Sm4—Se1^xvi	3.0526 (9)
Se4^i—Cs1—Se4^ii	71.90 (3)	Se2^ii—Sm2—Se1	86.77 (3)
Se4^i—Cs1—Se6^ii	125.93 (3)	Se3^ii—Sm2—Se1	85.54 (3)
Se4^ii—Cs1—Se6^ii	85.24 (2)	Se3^i—Sm2—Se1	85.54 (3)
Se4^i—Cs1—Se6^i	85.24 (2)	Se4^xiv—Sm3—Se4^xv	95.63 (4)
Se4^ii—Cs1—Se6^i	125.93 (3)	Se4^xiv—Sm3—Se3	85.26 (3)
Se6^ii—Cs1—Se6^i	69.55 (3)	Se4^xv—Sm3—Se3	85.26 (3)
Se4^i—Cs1—Se3^iii	64.04 (3)	Se4^xiv—Sm3—Se6	86.87 (3)
Se4^ii—Cs1—Se3^iii	64.04 (3)	Se4^xv—Sm3—Se6	86.87 (3)
Se6^ii—Cs1—Se3^iii	143.874 (16)	Se3—Sm3—Se6	168.27 (4)
Se6^i—Cs1—Se3^iii	143.874 (16)	Se4^xiv—Sm3—Se1^xvi	171.05 (4)
Se4^i—Cs1—Se5^i	90.60 (2)	Se4^xv—Sm3—Se1^xvi	87.03 (2)
Se4^ii—Cs1—Se5^i	131.59 (3)	Se3—Sm3—Se1^xvi	86.44 (3)
Se6^ii—Cs1—Se5^i	137.25 (3)	Se6—Sm3—Se1^xvi	101.84 (3)
Se6^i—Cs1—Se5^i	95.72 (2)	Se4^xiv—Sm3—Se1^xvii	87.03 (2)
Se3^iii—Cs1—Se5^i	67.69 (3)	Se4^xv—Sm3—Se1^xvii	171.05 (4)
Se4^i—Cs1—Se5^ii	131.59 (3)	Se3—Sm3—Se1^xvii	86.44 (3)
Se4^ii—Cs1—Se5^ii	90.60 (2)	Se6—Sm3—Se1^xvii	101.84 (3)
Se6^ii—Cs1—Se5^ii	95.72 (2)	Se1^xvi—Sm3—Se1^xvii	89.10 (3)
Se6^i—Cs1—Se5^ii	137.25 (3)	Se4—Sm4—Se2	172.93 (4)
Se3^iii—Cs1—Se5^ii	67.69 (3)	Se4—Sm4—Se6^xviii	87.59 (3)
Se5^i—Cs1—Se5^ii	67.63 (2)	Se2—Sm4—Se6^xviii	97.20 (3)
Se2^ii—Cs2—Se2^vii	95.31 (3)	Se4—Sm4—Se6^xix	87.59 (3)
Se2^i—Cs2—Se2^vii	141.35 (6)	Se2—Sm4—Se6^xix	97.20 (3)
Se2^ii—Cs2—Se2^viii	141.35 (6)	Se6^xviii—Sm4—Se6^xix	94.28 (4)
Se2^i—Cs2—Se2^viii	95.31 (3)	Se4—Sm4—Se1^xvii	87.63 (3)
Se2^vii—Cs2—Se2^viii	70.00 (4)	Se2—Sm4—Se1^xvii	87.29 (3)
Se2^ii—Cs2—Se5^iii	138.46 (3)	Se6^xviii—Sm4—Se1^xvii	174.23 (4)
Se2^i—Cs2—Se5^iii	138.46 (3)	Se6^xix—Sm4—Se1^xvii	88.74 (2)
Se2^vii—Cs2—Se5^iii	72.81 (4)	Se4—Sm4—Se1^xvi	87.63 (3)
Se2^viii—Cs2—Se5^iii	72.81 (4)	Se2—Sm4—Se1^xvi	87.29 (3)
Se2^ii—Cs2—Se6^iii	70.80 (4)	Se6^xviii—Sm4—Se1^xvi	88.74 (2)
Se2^i—Cs2—Se6^iii	70.80 (4)	Se6^xix—Sm4—Se1^xvi	174.23 (4)
Se2^vii—Cs2—Se6^iii	141.36 (3)	Se1^xvii—Sm4—Se1^xvi	87.85 (3)
Se2^viii—Cs2—Se6^iii	141.36 (3)	Sm3^ii—Se1—Sm3^i	89.10 (3)
Se5^iii—Cs2—Se6^iii	93.63 (5)	Sm3^ii—Se1—Sm4^i	178.80 (4)
Se3^i—Sm1—Se3^ix	180.000 (14)	Sm3^i—Se1—Sm4^i	91.519 (12)
Se3^i—Sm1—Se5^x	92.43 (3)	Sm3^ii—Se1—Sm4^ii	91.519 (12)
Se3^ix—Sm1—Se5^x	87.57 (3)	Sm3^i—Se1—Sm4^ii	178.80 (4)
Se3^i—Sm1—Se5^xi	87.57 (3)	Sm4^i—Se1—Sm4^ii	87.85 (3)
Se3^ix—Sm1—Se5^xi	92.43 (3)	Sm3^ii—Se1—Sm2	91.46 (3)
Se5^x—Sm1—Se5^xi	180.00 (4)	Sm3^i—Se1—Sm2	91.46 (3)
Se3^i—Sm1—Se5^xii	92.43 (3)	Sm4^i—Se1—Sm2	89.55 (3)
Se3^ix—Sm1—Se5^xii	87.57 (3)	Sm4^ii—Se1—Sm2	89.55 (3)
Se5^x—Sm1—Se5^xii	92.44 (3)	Sm4—Se2—Sm2^xvii	96.22 (3)
Se5^xi—Sm1—Se5^xii	87.56 (3)	Sm4—Se2—Sm2^xvi	96.22 (3)
Se3^i—Sm1—Se5^xiii	87.57 (3)	Sm2^xvii—Se2—Sm2^xvi	93.72 (4)
Se3^ix—Sm1—Se5^xiii	92.43 (3)	Sm1^viii—Se3—Sm3	167.99 (5)
Se5^x—Sm1—Se5^xiii	87.56 (3)	Sm1^viii—Se3—Sm2^xvi	91.79 (3)
Se5^xi—Sm1—Se5^xiii	92.44 (3)	Sm3—Se3—Sm2^xvi	96.47 (3)
Se5^xii—Sm1—Se5^xiii	180.0	Sm1^viii—Se3—Sm2^xvii	91.79 (3)
Se5^xiii—Sm2—Se2^i	99.19 (3)	Sm3—Se3—Sm2^xvii	96.47 (3)
Se5^xiii—Sm2—Se2^ii	99.19 (3)	Sm2^xvi—Se3—Sm2^xvii	92.90 (4)
Se2^i—Sm2—Se2^ii	93.72 (4)	Sm3^xviii—Se4—Sm3^xix	95.63 (4)
Se5^xiii—Sm2—Se3^ii	88.41 (3)	Sm3^xviii—Se4—Sm4	93.81 (3)
Se2^i—Sm2—Se3^ii	172.31 (4)	Sm3^xix—Se4—Sm4	93.81 (3)
Se2^ii—Sm2—Se3^ii	86.18 (2)	Sm2^xx—Se5—Sm1^xxi	92.23 (3)
Se5^xiii—Sm2—Se3^i	88.41 (3)	Sm2^xx—Se5—Sm1^xx	92.23 (3)
Se2^i—Sm2—Se3^i	86.18 (2)	Sm1^xxi—Se5—Sm1^xx	92.44 (3)
Se2^ii—Sm2—Se3^i	172.31 (4)	Sm4^xiv—Se6—Sm4^xv	94.28 (4)
Se3^ii—Sm2—Se3^i	92.90 (4)	Sm4^xiv—Se6—Sm3	91.72 (3)
Se5^xiii—Sm2—Se1	171.21 (4)	Sm4^xv—Se6—Sm3	91.72 (3)
Se2^i—Sm2—Se1	86.77 (3)

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