Cs₆Nb₄Se₂₂ and K₁₂Nb₆Se_35.3: two new compounds containing the M₄Q₂₂ building block

The title compounds, namely hexa­caesium tetra­niobium docosa­selenide and dodeca­potassium hexa­niobium penta­triacontaselenide, were formed from their respective alkali chalcogenide reactive flux and niobium metal. Both compounds fall into the larger family of solid-state compounds that contain the M₂Q₁₁ building block (M = Nb, Ta; Q = Se, S), where the metal chalcogenide forms dimers of face-shared penta­gonal bipyramids. Cs₆Nb₄Se₂₂ contains two Nb₂Se₁₁ building blocks linked by an Se-Se bond to form isolated Nb₄Se₂₂ tetra­meric building blocks surrounded by caesium ions. K₁₂Nb₆Se_35.3 contains similar Nb₄Se₂₂ tetra­mers that are linked by an Se-Se-Se unit to an Nb₂Se₁₁ dimer to form one-dimensional anionic chains surrounded by potassium ions. Further crystallographic studies of K₁₂Nb₆Se_35.3 demonstrate a new M₂Se₁₂ building block because of disorder between an Se^2- site (85%) and an (Se-Se)^2- unit (15%). The subtle differences between the structures are discussed.

Computing details

For both compounds, data collection: APEX2 (Bruker, 2008); cell refinement: SAINT-Plus (Bruker, 2008). Data reduction: SAINT-Plus (Bruker, 2008) for (I); SAINT-Plus (Bruker 2008) for (II). For both compounds, program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CrystalMaker (CrystalMaker Software, 2009); software used to prepare material for publication: APEX2 (Bruker, 2008).

(I) Hexacaesium tetraniobium docosaselenide

Crystal data

Cs6Nb4Se22	F(000) = 2484
Mr = 2906.22	Dx = 4.566 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 12.5887 (6) Å	Cell parameters from 5633 reflections
b = 8.5127 (4) Å	θ = 4.7–52.1°
c = 20.3151 (10) Å	µ = 25.10 mm^−1
β = 103.853 (1)°	T = 296 K
V = 2113.72 (18) Å^3	Needle, black
Z = 2	0.2 × 0.08 × 0.06 mm

Data collection

Bruker APEXII CCD diffractometer	4844 independent reflections
Radiation source: fine-focus sealed tube	3550 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.065
ω and φ scans	θmax = 27.5°, θmin = 1.7°
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2008)	h = −16→16
Tmin = 0.347, Tmax = 0.746	k = −11→10
35929 measured reflections	l = −26→26

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.038	Secondary atom site location: difference Fourier map
wR(F^2) = 0.089	w = 1/[σ^2(Fo^2) + (0.031P)^2 + 18.3443P] where P = (Fo^2 + 2Fc^2)/3
S = 1.03	(Δ/σ)max = 0.001
4844 reflections	Δρmax = 4.93 e Å^−3
145 parameters	Δρmin = −2.29 e Å^−3

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
Nb1	0.80152 (6)	0.23308 (9)	0.50654 (4)	0.02341 (17)
Nb2	0.70707 (7)	0.35623 (10)	0.66030 (4)	0.03012 (19)
Se1	1.00252 (7)	0.13484 (10)	0.51394 (5)	0.0294 (2)
Se2	0.89435 (7)	0.23574 (11)	0.65594 (4)	0.0299 (2)
Se3	0.73578 (7)	0.50305 (10)	0.54883 (5)	0.0303 (2)
Se4	0.75335 (8)	−0.05493 (11)	0.52764 (5)	0.0371 (2)
Se5	0.79063 (8)	0.10354 (12)	0.72163 (5)	0.0388 (2)
Se6	0.51018 (8)	0.43174 (14)	0.59217 (6)	0.0465 (3)
Se7	0.74133 (9)	0.26233 (15)	0.38919 (5)	0.0486 (3)
Se8	0.62574 (7)	0.14011 (11)	0.54042 (4)	0.0308 (2)
Se9	0.92141 (7)	0.48537 (10)	0.54525 (5)	0.0316 (2)
Se10	0.52464 (10)	0.27314 (17)	0.68849 (6)	0.0615 (3)
Se11	0.76529 (11)	0.56779 (15)	0.73383 (6)	0.0614 (4)
Cs1	1.00418 (6)	0.17210 (8)	0.33806 (3)	0.04514 (17)
Cs2	0.54136 (7)	−0.15562 (9)	0.64033 (4)	0.0602 (2)
Cs3	1.22961 (6)	0.31969 (9)	0.62045 (3)	0.0537 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Nb1	0.0223 (4)	0.0250 (4)	0.0232 (4)	−0.0013 (3)	0.0058 (3)	−0.0011 (3)
Nb2	0.0288 (4)	0.0372 (5)	0.0244 (4)	0.0052 (4)	0.0065 (3)	−0.0027 (3)
Se1	0.0241 (4)	0.0249 (4)	0.0399 (5)	−0.0008 (4)	0.0091 (4)	−0.0057 (4)
Se2	0.0266 (5)	0.0329 (5)	0.0283 (4)	0.0025 (4)	0.0030 (4)	−0.0020 (4)
Se3	0.0296 (5)	0.0281 (5)	0.0333 (5)	0.0059 (4)	0.0077 (4)	0.0017 (4)
Se4	0.0404 (6)	0.0267 (5)	0.0456 (6)	−0.0062 (4)	0.0130 (4)	−0.0052 (4)
Se5	0.0426 (6)	0.0425 (6)	0.0307 (5)	0.0006 (5)	0.0074 (4)	0.0066 (4)
Se6	0.0284 (5)	0.0624 (7)	0.0478 (6)	0.0093 (5)	0.0072 (4)	−0.0012 (5)
Se7	0.0434 (6)	0.0696 (8)	0.0328 (5)	−0.0024 (5)	0.0095 (5)	0.0011 (5)
Se8	0.0253 (5)	0.0384 (5)	0.0289 (5)	−0.0066 (4)	0.0070 (4)	−0.0013 (4)
Se9	0.0297 (5)	0.0262 (4)	0.0395 (5)	−0.0042 (4)	0.0094 (4)	−0.0019 (4)
Se10	0.0458 (7)	0.0906 (10)	0.0580 (7)	0.0078 (7)	0.0321 (6)	0.0115 (7)
Se11	0.0697 (8)	0.0578 (7)	0.0471 (7)	0.0178 (6)	−0.0050 (6)	−0.0236 (6)
Cs1	0.0521 (4)	0.0457 (4)	0.0337 (3)	0.0115 (3)	0.0025 (3)	−0.0012 (3)
Cs2	0.0660 (5)	0.0573 (5)	0.0511 (4)	−0.0158 (4)	0.0019 (4)	0.0129 (3)
Cs3	0.0447 (4)	0.0707 (5)	0.0399 (4)	−0.0153 (4)	−0.0013 (3)	0.0100 (3)

Geometric parameters (Å, º)

Nb1—Se7	2.3355 (13)	Se7—Cs1	3.7768 (13)
Nb1—Se4	2.5859 (12)	Se8—Cs2	3.5522 (11)
Nb1—Se8	2.5934 (12)	Se8—Cs2^vii	3.7719 (11)
Nb1—Se9	2.6344 (11)	Se9—Cs1^iii	3.7331 (11)
Nb1—Se1	2.6348 (12)	Se9—Cs3^iii	3.8255 (12)
Nb1—Se3	2.6543 (11)	Se9—Cs3	4.0667 (12)
Nb1—Se2	2.9799 (11)	Se10—Cs3^vi	3.6610 (15)
Nb2—Se11	2.3425 (14)	Se10—Cs2	3.7976 (17)
Nb2—Se5	2.5804 (13)	Se10—Cs2^viii	3.8124 (14)
Nb2—Se2	2.5919 (12)	Se11—Cs3^ix	3.6436 (13)
Nb2—Se10	2.5948 (14)	Se11—Cs2^v	3.8123 (15)
Nb2—Se6	2.6134 (13)	Se11—Cs1^ii	3.8274 (14)
Nb2—Se3	2.6856 (12)	Se11—Cs1^iii	4.1818 (17)
Nb2—Se8	3.0283 (12)	Cs1—Se5^x	3.6640 (12)
Se1—Se1^i	2.3616 (17)	Cs1—Se2^i	3.6913 (11)
Se1—Cs3	3.5170 (11)	Cs1—Se2^x	3.7102 (11)
Se1—Cs1	3.5920 (11)	Cs1—Se4^i	3.7105 (12)
Se1—Cs1^i	3.9994 (11)	Cs1—Se9^iii	3.7331 (11)
Se2—Se5	2.3636 (13)	Cs1—Se11^x	3.8274 (14)
Se2—Cs1^i	3.6913 (11)	Cs1—Se5^i	3.8922 (12)
Se2—Cs1^ii	3.7102 (11)	Cs1—Se1^i	3.9994 (11)
Se3—Se9	2.3601 (13)	Cs1—Se11^iii	4.1818 (17)
Se3—Cs3^iii	3.8743 (11)	Cs2—Se7^vii	3.5815 (14)
Se4—Se8	2.3674 (13)	Cs2—Se6^xi	3.6423 (15)
Se4—Cs1^i	3.7105 (12)	Cs2—Se8^vii	3.7719 (11)
Se4—Cs3^i	3.8058 (12)	Cs2—Se11^xi	3.8123 (15)
Se4—Cs2	4.0030 (13)	Cs2—Se10^xii	3.8124 (14)
Se5—Cs1^ii	3.6640 (12)	Cs3—Se7^iii	3.5870 (15)
Se5—Cs2	3.8678 (13)	Cs3—Se11^iv	3.6436 (13)
Se5—Cs1^i	3.8921 (12)	Cs3—Se10^xiii	3.6610 (15)
Se5—Cs3^iv	4.0728 (12)	Cs3—Se4^i	3.8058 (12)
Se6—Se10	2.3483 (17)	Cs3—Se9^iii	3.8255 (12)
Se6—Cs2^v	3.6423 (14)	Cs3—Se6^xiii	3.8323 (13)
Se6—Cs3^vi	3.8323 (13)	Cs3—Se3^iii	3.8742 (11)
Se7—Cs2^vii	3.5815 (14)	Cs3—Se5^ix	4.0728 (12)
Se7—Cs3^iii	3.5871 (15)
Se7—Nb1—Se4	103.80 (5)	Nb2—Se11—Cs1^iii	108.77 (5)
Se7—Nb1—Se8	102.39 (4)	Cs3^ix—Se11—Cs1^iii	95.36 (3)
Se4—Nb1—Se8	54.40 (3)	Cs2^v—Se11—Cs1^iii	89.50 (3)
Se7—Nb1—Se9	103.91 (4)	Cs1^ii—Se11—Cs1^iii	87.52 (3)
Se4—Nb1—Se9	149.74 (4)	Se1—Cs1—Se5^x	120.67 (3)
Se8—Nb1—Se9	129.33 (4)	Se1—Cs1—Se2^i	88.20 (2)
Se7—Nb1—Se1	99.47 (4)	Se5^x—Cs1—Se2^i	134.93 (3)
Se4—Nb1—Se1	87.12 (4)	Se1—Cs1—Se2^x	157.07 (3)
Se8—Nb1—Se1	139.18 (4)	Se5^x—Cs1—Se2^x	37.38 (2)
Se9—Nb1—Se1	76.59 (3)	Se2^i—Cs1—Se2^x	105.97 (2)
Se7—Nb1—Se3	100.84 (4)	Se1—Cs1—Se4^i	56.26 (2)
Se4—Nb1—Se3	131.58 (4)	Se5^x—Cs1—Se4^i	164.17 (3)
Se8—Nb1—Se3	80.00 (4)	Se2^i—Cs1—Se4^i	60.37 (2)
Se9—Nb1—Se3	53.01 (3)	Se2^x—Cs1—Se4^i	146.58 (3)
Se1—Nb1—Se3	128.75 (4)	Se1—Cs1—Se9^iii	59.85 (2)
Se7—Nb1—Se2	172.37 (5)	Se5^x—Cs1—Se9^iii	92.09 (3)
Se4—Nb1—Se2	83.61 (3)	Se2^i—Cs1—Se9^iii	132.96 (3)
Se8—Nb1—Se2	83.31 (3)	Se2^x—Cs1—Se9^iii	116.42 (3)
Se9—Nb1—Se2	68.46 (3)	Se4^i—Cs1—Se9^iii	72.89 (2)
Se1—Nb1—Se2	78.89 (3)	Se1—Cs1—Se7	61.98 (2)
Se3—Nb1—Se2	74.95 (3)	Se5^x—Cs1—Se7	61.04 (3)
Se11—Nb2—Se5	107.69 (5)	Se2^i—Cs1—Se7	120.08 (3)
Se11—Nb2—Se2	100.24 (5)	Se2^x—Cs1—Se7	95.13 (3)
Se5—Nb2—Se2	54.38 (3)	Se4^i—Cs1—Se7	118.23 (3)
Se11—Nb2—Se10	103.13 (6)	Se9^iii—Cs1—Se7	76.68 (3)
Se5—Nb2—Se10	86.92 (5)	Se1—Cs1—Se11^x	108.20 (3)
Se2—Nb2—Se10	139.47 (5)	Se5^x—Cs1—Se11^x	64.09 (3)
Se11—Nb2—Se6	105.12 (5)	Se2^i—Cs1—Se11^x	74.71 (3)
Se5—Nb2—Se6	133.32 (5)	Se2^x—Cs1—Se11^x	60.35 (2)
Se2—Nb2—Se6	146.55 (4)	Se4^i—Cs1—Se11^x	131.49 (3)
Se10—Nb2—Se6	53.60 (4)	Se9^iii—Cs1—Se11^x	144.35 (3)
Se11—Nb2—Se3	95.46 (5)	Se7—Cs1—Se11^x	68.69 (3)
Se5—Nb2—Se3	132.34 (4)	Se1—Cs1—Se5^i	114.77 (3)
Se2—Nb2—Se3	81.27 (4)	Se5^x—Cs1—Se5^i	123.52 (2)
Se10—Nb2—Se3	128.16 (5)	Se2^i—Cs1—Se5^i	36.20 (2)
Se6—Nb2—Se3	74.99 (4)	Se2^x—Cs1—Se5^i	86.18 (2)
Se11—Nb2—Se8	166.86 (5)	Se4^i—Cs1—Se5^i	64.95 (2)
Se5—Nb2—Se8	84.38 (4)	Se9^iii—Cs1—Se5^i	125.76 (3)
Se2—Nb2—Se8	82.37 (3)	Se7—Cs1—Se5^i	154.00 (3)
Se10—Nb2—Se8	82.25 (4)	Se11^x—Cs1—Se5^i	89.89 (3)
Se6—Nb2—Se8	68.18 (4)	Se1—Cs1—Se1^i	35.74 (3)
Se3—Nb2—Se8	72.09 (3)	Se5^x—Cs1—Se1^i	132.97 (3)
Se1^i—Se1—Nb1	108.94 (5)	Se2^i—Cs1—Se1^i	55.26 (2)
Se1^i—Se1—Cs3	123.62 (5)	Se2^x—Cs1—Se1^i	144.87 (3)
Nb1—Se1—Cs3	121.41 (4)	Se4^i—Cs1—Se1^i	55.48 (2)
Se1^i—Se1—Cs1	81.58 (5)	Se9^iii—Cs1—Se1^i	94.60 (2)
Nb1—Se1—Cs1	98.60 (3)	Se7—Cs1—Se1^i	75.44 (2)
Cs3—Se1—Cs1	112.02 (3)	Se11^x—Cs1—Se1^i	84.96 (2)
Se1^i—Se1—Cs1^i	62.68 (4)	Se5^i—Cs1—Se1^i	88.59 (2)
Nb1—Se1—Cs1^i	93.29 (3)	Se1—Cs1—Se11^iii	124.33 (3)
Cs3—Se1—Cs1^i	89.44 (2)	Se5^x—Cs1—Se11^iii	87.81 (3)
Cs1—Se1—Cs1^i	144.26 (2)	Se2^i—Cs1—Se11^iii	104.24 (3)
Se5—Se2—Nb2	62.56 (4)	Se2^x—Cs1—Se11^iii	70.36 (2)
Se5—Se2—Nb1	115.88 (4)	Se4^i—Cs1—Se11^iii	83.20 (3)
Nb2—Se2—Nb1	84.24 (3)	Se9^iii—Cs1—Se11^iii	73.65 (2)
Se5—Se2—Cs1^i	76.53 (4)	Se7—Cs1—Se11^iii	135.67 (3)
Nb2—Se2—Cs1^i	132.96 (4)	Se11^x—Cs1—Se11^iii	127.47 (2)
Nb1—Se2—Cs1^i	94.28 (3)	Se5^i—Cs1—Se11^iii	69.06 (2)
Se5—Se2—Cs1^ii	70.25 (3)	Se1^i—Cs1—Se11^iii	138.57 (3)
Nb2—Se2—Cs1^ii	90.41 (3)	Se8—Cs2—Se7^vii	120.34 (3)
Nb1—Se2—Cs1^ii	168.21 (4)	Se8—Cs2—Se6^xi	123.90 (3)
Cs1^i—Se2—Cs1^ii	97.04 (2)	Se7^vii—Cs2—Se6^xi	70.83 (3)
Se9—Se3—Nb1	63.07 (3)	Se8—Cs2—Se8^vii	65.94 (3)
Se9—Se3—Nb2	109.29 (4)	Se7^vii—Cs2—Se8^vii	62.98 (2)
Nb1—Se3—Nb2	89.16 (4)	Se6^xi—Cs2—Se8^vii	76.89 (3)
Se9—Se3—Cs3^iii	71.03 (3)	Se8—Cs2—Se10	60.57 (3)
Nb1—Se3—Cs3^iii	86.55 (3)	Se7^vii—Cs2—Se10	99.95 (3)
Nb2—Se3—Cs3^iii	174.95 (4)	Se6^xi—Cs2—Se10	170.77 (4)
Se8—Se4—Nb1	62.96 (4)	Se8^vii—Cs2—Se10	99.48 (3)
Se8—Se4—Cs1^i	124.63 (4)	Se8—Cs2—Se11^xi	115.83 (4)
Nb1—Se4—Cs1^i	101.10 (3)	Se7^vii—Cs2—Se11^xi	120.89 (4)
Se8—Se4—Cs3^i	132.08 (4)	Se6^xi—Cs2—Se11^xi	63.74 (3)
Nb1—Se4—Cs3^i	111.76 (4)	Se8^vii—Cs2—Se11^xi	132.86 (3)
Cs1^i—Se4—Cs3^i	103.29 (3)	Se10—Cs2—Se11^xi	123.04 (3)
Se8—Se4—Cs2	61.62 (3)	Se8—Cs2—Se10^xii	142.58 (4)
Nb1—Se4—Cs2	120.84 (4)	Se7^vii—Cs2—Se10^xii	71.80 (3)
Cs1^i—Se4—Cs2	93.76 (3)	Se6^xi—Cs2—Se10^xii	93.36 (3)
Cs3^i—Se4—Cs2	119.78 (3)	Se8^vii—Cs2—Se10^xii	134.51 (3)
Se2—Se5—Nb2	63.06 (4)	Se10—Cs2—Se10^xii	83.12 (3)
Se2—Se5—Cs1^ii	72.37 (3)	Se11^xi—Cs2—Se10^xii	75.16 (3)
Nb2—Se5—Cs1^ii	91.63 (4)	Se8—Cs2—Se5	61.10 (2)
Se2—Se5—Cs2	122.13 (4)	Se7^vii—Cs2—Se5	152.65 (4)
Nb2—Se5—Cs2	94.25 (4)	Se6^xi—Cs2—Se5	133.55 (3)
Cs1^ii—Se5—Cs2	165.43 (3)	Se8^vii—Cs2—Se5	127.02 (3)
Se2—Se5—Cs1^i	67.27 (3)	Se10—Cs2—Se5	55.33 (3)
Nb2—Se5—Cs1^i	125.19 (4)	Se11^xi—Cs2—Se5	73.26 (3)
Cs1^ii—Se5—Cs1^i	94.37 (2)	Se10^xii—Cs2—Se5	91.89 (3)
Cs2—Se5—Cs1^i	93.11 (3)	Se8—Cs2—Se4	35.90 (2)
Se2—Se5—Cs3^iv	150.98 (4)	Se7^vii—Cs2—Se4	136.91 (3)
Nb2—Se5—Cs3^iv	141.24 (4)	Se6^xi—Cs2—Se4	95.54 (3)
Cs1^ii—Se5—Cs3^iv	88.59 (2)	Se8^vii—Cs2—Se4	74.25 (2)
Cs2—Se5—Cs3^iv	78.50 (2)	Se10—Cs2—Se4	91.56 (3)
Cs1^i—Se5—Cs3^iv	93.39 (3)	Se11^xi—Cs2—Se4	84.40 (3)
Se10—Se6—Nb2	62.79 (4)	Se10^xii—Cs2—Se4	151.22 (3)
Se10—Se6—Cs2^v	110.41 (5)	Se5—Cs2—Se4	62.50 (2)
Nb2—Se6—Cs2^v	93.86 (4)	Se1—Cs3—Se7^iii	119.26 (3)
Se10—Se6—Cs3^vi	67.81 (4)	Se1—Cs3—Se11^iv	95.17 (3)
Nb2—Se6—Cs3^vi	130.59 (4)	Se7^iii—Cs3—Se11^iv	130.24 (3)
Cs2^v—Se6—Cs3^vi	104.10 (3)	Se1—Cs3—Se10^xiii	141.78 (4)
Nb1—Se7—Cs2^vii	102.15 (4)	Se7^iii—Cs3—Se10^xiii	91.17 (3)
Nb1—Se7—Cs3^iii	98.57 (4)	Se11^iv—Cs3—Se10^xiii	79.08 (3)
Cs2^vii—Se7—Cs3^iii	110.65 (4)	Se1—Cs3—Se4^i	55.95 (2)
Nb1—Se7—Cs1	99.65 (4)	Se7^iii—Cs3—Se4^i	121.23 (3)
Cs2^vii—Se7—Cs1	143.44 (4)	Se11^iv—Cs3—Se4^i	107.48 (3)
Cs3^iii—Se7—Cs1	94.54 (3)	Se10^xiii—Cs3—Se4^i	89.45 (3)
Se4—Se8—Nb1	62.64 (4)	Se1—Cs3—Se9^iii	59.55 (2)
Se4—Se8—Nb2	113.99 (4)	Se7^iii—Cs3—Se9^iii	63.73 (2)
Nb1—Se8—Nb2	83.24 (3)	Se11^iv—Cs3—Se9^iii	151.47 (3)
Se4—Se8—Cs2	82.49 (4)	Se10^xiii—Cs3—Se9^iii	128.66 (3)
Nb1—Se8—Cs2	139.36 (4)	Se4^i—Cs3—Se9^iii	70.83 (2)
Nb2—Se8—Cs2	93.49 (3)	Se1—Cs3—Se6^xiii	131.43 (3)
Se4—Se8—Cs2^vii	98.78 (4)	Se7^iii—Cs3—Se6^xiii	68.61 (3)
Nb1—Se8—Cs2^vii	92.49 (3)	Se11^iv—Cs3—Se6^xiii	115.51 (3)
Nb2—Se8—Cs2^vii	139.82 (4)	Se10^xiii—Cs3—Se6^xiii	36.44 (3)
Cs2—Se8—Cs2^vii	114.06 (3)	Se4^i—Cs3—Se6^xiii	78.49 (3)
Se3—Se9—Nb1	63.93 (3)	Se9^iii—Cs3—Se6^xiii	92.40 (3)
Se3—Se9—Cs1^iii	91.74 (4)	Se1—Cs3—Se3^iii	82.86 (2)
Nb1—Se9—Cs1^iii	149.89 (4)	Se7^iii—Cs3—Se3^iii	62.00 (2)
Se3—Se9—Cs3^iii	73.28 (3)	Se11^iv—Cs3—Se3^iii	165.15 (4)
Nb1—Se9—Cs3^iii	87.85 (3)	Se10^xiii—Cs3—Se3^iii	93.31 (3)
Cs1^iii—Se9—Cs3^iii	102.48 (3)	Se4^i—Cs3—Se3^iii	59.30 (2)
Se3—Se9—Cs3	150.83 (4)	Se9^iii—Cs3—Se3^iii	35.69 (2)
Nb1—Se9—Cs3	104.85 (3)	Se6^xiii—Cs3—Se3^iii	57.75 (2)
Cs1^iii—Se9—Cs3	87.74 (2)	Se1—Cs3—Se9	50.37 (2)
Cs3^iii—Se9—Cs3	135.19 (3)	Se7^iii—Cs3—Se9	74.70 (3)
Se6—Se10—Nb2	63.61 (4)	Se11^iv—Cs3—Se9	109.81 (3)
Se6—Se10—Cs3^vi	75.76 (4)	Se10^xiii—Cs3—Se9	165.87 (3)
Nb2—Se10—Cs3^vi	139.35 (5)	Se4^i—Cs3—Se9	97.91 (2)
Se6—Se10—Cs2	109.63 (5)	Se9^iii—Cs3—Se9	44.81 (3)
Nb2—Se10—Cs2	95.66 (4)	Se6^xiii—Cs3—Se9	133.47 (3)
Cs3^vi—Se10—Cs2	96.92 (4)	Se3^iii—Cs3—Se9	80.30 (2)
Se6—Se10—Cs2^viii	132.71 (6)	Se1—Cs3—Se5^ix	123.72 (3)
Nb2—Se10—Cs2^viii	123.76 (5)	Se7^iii—Cs3—Se5^ix	58.73 (3)
Cs3^vi—Se10—Cs2^viii	84.51 (3)	Se11^iv—Cs3—Se5^ix	72.62 (3)
Cs2—Se10—Cs2^viii	115.18 (4)	Se10^xiii—Cs3—Se5^ix	90.91 (3)
Nb2—Se11—Cs3^ix	155.85 (6)	Se4^i—Cs3—Se5^ix	179.64 (3)
Nb2—Se11—Cs2^v	94.36 (4)	Se9^iii—Cs3—Se5^ix	108.91 (3)
Cs3^ix—Se11—Cs2^v	84.74 (3)	Se6^xiii—Cs3—Se5^ix	101.78 (3)
Nb2—Se11—Cs1^ii	91.55 (4)	Se3^iii—Cs3—Se5^ix	120.64 (3)
Cs3^ix—Se11—Cs1^ii	90.33 (3)	Se9—Cs3—Se5^ix	81.73 (2)
Cs2^v—Se11—Cs1^ii	173.98 (4)

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

(II) dodecapotassium hexaniobium pentatriacontaselenide

Crystal data

K12Nb6Se35.30	Dx = 4.099 Mg m^−3
Mr = 3810.00	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbcn	Cell parameters from 8508 reflections
a = 8.3290 (4) Å	θ = 4.4–48.7°
b = 13.2559 (7) Å	µ = 22.69 mm^−1
c = 55.974 (3) Å	T = 100 K
V = 6180.0 (5) Å^3	Plate, black
Z = 4	0.16 × 0.12 × 0.02 mm
F(000) = 6697

Data collection

Bruker APEXII CCD diffractometer	5107 independent reflections
Radiation source: fine-focus sealed tube	4470 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.074
ω and φ scans	θmax = 24.4°, θmin = 1.5°
Absorption correction: empirical (using intensity measurements) (SADABS; Bruker, 2008)	h = −9→9
Tmin = 0.380, Tmax = 0.745	k = −15→15
53662 measured reflections	l = −65→65

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	Primary atom site location: structure-invariant direct methods
R[F^2 > 2σ(F^2)] = 0.031	Secondary atom site location: difference Fourier map
wR(F^2) = 0.063	w = 1/[σ^2(Fo^2) + (0.0014P)^2 + 93.4847P] where P = (Fo^2 + 2Fc^2)/3
S = 1.12	(Δ/σ)max = 0.001
5107 reflections	Δρmax = 1.96 e Å^−3
263 parameters	Δρmin = −0.97 e Å^−3

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)
Nb1	0.04055 (8)	0.13613 (5)	0.047032 (13)	0.00663 (16)
Nb2	−0.56408 (9)	0.21560 (5)	0.218406 (13)	0.00765 (16)
Nb3	0.04190 (8)	0.05393 (5)	0.110845 (13)	0.00614 (16)
Se1	0.34720 (9)	0.10761 (6)	0.050461 (15)	0.01015 (18)
Se2	−0.19337 (9)	0.14446 (6)	0.077886 (14)	0.00756 (17)
Se3	−0.08333 (10)	−0.11819 (6)	0.097098 (15)	0.00894 (18)
Se4	−0.43858 (10)	0.09735 (6)	0.186624 (15)	0.01356 (19)
Se5	0.12568 (9)	−0.04697 (6)	0.073411 (14)	0.00742 (17)
Se6	0.00073 (10)	0.24204 (6)	0.119925 (15)	0.00955 (18)
Se7	0.11822 (10)	0.01882 (6)	0.011250 (15)	0.01058 (18)
Se8	−0.71760 (9)	0.15174 (6)	0.255859 (14)	0.00871 (18)
Se9	0.20400 (9)	0.19291 (6)	0.085980 (14)	0.00792 (18)
Se10	−0.67021 (10)	0.03176 (6)	0.225458 (15)	0.01108 (18)
Se11	0.24578 (10)	0.00344 (6)	0.137888 (15)	0.01300 (19)
Se12	−0.23252 (9)	0.04710 (6)	0.042809 (14)	0.01003 (18)
Se13	−0.21767 (10)	0.02909 (6)	0.136669 (14)	0.01073 (18)
Se14	−0.32294 (10)	0.33432 (6)	0.211489 (15)	0.01188 (19)
Se16	−0.25798 (10)	0.17889 (6)	0.159701 (15)	0.01254 (19)
Se15	−0.5000	0.36262 (8)	0.2500	0.0087 (2)
Se17	−0.77138 (11)	0.29302 (7)	0.196531 (16)	0.0174 (2)
Se18	0.01459 (15)	0.29337 (8)	0.02814 (2)	0.0145 (2)	0.85
Se19	−0.1020 (8)	0.2440 (5)	0.01393 (12)	0.0242 (15)	0.15
Se20	0.0966 (9)	0.3188 (5)	0.03782 (14)	0.0260 (16)	0.15
K1	0.5000	0.0000	0.0000	0.0172 (6)
K2	0.5000	−0.1672 (2)	0.2500	0.0141 (6)
K3	0.0893 (3)	0.19994 (16)	−0.03207 (4)	0.0286 (5)
K4	0.0147 (2)	0.04036 (16)	0.18954 (4)	0.0246 (5)
K5	−0.0265 (2)	0.44109 (17)	0.08581 (4)	0.0260 (5)
K6	0.5523 (2)	−0.11994 (14)	0.16630 (3)	0.0167 (4)
K7	0.3839 (2)	0.24864 (15)	0.14025 (3)	0.0158 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Nb1	0.0056 (4)	0.0095 (4)	0.0048 (4)	−0.0010 (3)	0.0008 (3)	−0.0001 (3)
Nb2	0.0094 (4)	0.0083 (4)	0.0052 (4)	−0.0009 (3)	0.0005 (3)	−0.0010 (3)
Nb3	0.0067 (4)	0.0074 (4)	0.0044 (4)	−0.0001 (3)	−0.0006 (3)	0.0004 (3)
Se1	0.0057 (4)	0.0170 (5)	0.0077 (4)	−0.0009 (3)	0.0013 (3)	−0.0015 (4)
Se2	0.0071 (4)	0.0094 (4)	0.0061 (4)	0.0015 (3)	0.0013 (3)	−0.0001 (3)
Se3	0.0094 (4)	0.0075 (4)	0.0099 (4)	−0.0012 (3)	0.0000 (3)	0.0002 (3)
Se4	0.0186 (5)	0.0125 (4)	0.0096 (4)	−0.0024 (4)	0.0060 (4)	−0.0038 (4)
Se5	0.0072 (4)	0.0085 (4)	0.0066 (4)	0.0017 (3)	0.0003 (3)	−0.0007 (3)
Se6	0.0134 (4)	0.0082 (4)	0.0071 (4)	−0.0001 (3)	0.0018 (3)	−0.0021 (3)
Se7	0.0071 (4)	0.0180 (5)	0.0066 (4)	0.0008 (3)	0.0000 (3)	−0.0045 (3)
Se8	0.0079 (4)	0.0108 (4)	0.0074 (4)	−0.0008 (3)	0.0010 (3)	−0.0003 (3)
Se9	0.0088 (4)	0.0088 (4)	0.0061 (4)	−0.0029 (3)	−0.0009 (3)	−0.0003 (3)
Se10	0.0133 (4)	0.0089 (4)	0.0111 (4)	−0.0024 (3)	0.0003 (3)	−0.0020 (3)
Se11	0.0140 (4)	0.0134 (4)	0.0116 (4)	0.0006 (4)	−0.0049 (4)	0.0013 (4)
Se12	0.0055 (4)	0.0169 (5)	0.0077 (4)	−0.0005 (3)	−0.0003 (3)	−0.0034 (3)
Se13	0.0108 (4)	0.0135 (4)	0.0079 (4)	−0.0017 (3)	0.0036 (3)	−0.0021 (3)
Se14	0.0136 (4)	0.0127 (4)	0.0093 (4)	−0.0044 (4)	0.0025 (4)	0.0017 (4)
Se16	0.0120 (4)	0.0136 (4)	0.0120 (4)	−0.0004 (4)	0.0040 (4)	−0.0026 (4)
Se15	0.0131 (6)	0.0064 (6)	0.0067 (6)	0.000	−0.0010 (5)	0.000
Se17	0.0185 (5)	0.0198 (5)	0.0138 (5)	0.0059 (4)	−0.0042 (4)	0.0004 (4)
Se18	0.0174 (6)	0.0125 (6)	0.0138 (6)	0.0016 (5)	0.0000 (5)	0.0044 (5)
Se19	0.027 (4)	0.020 (3)	0.026 (4)	0.002 (3)	−0.004 (3)	−0.005 (3)
Se20	0.028 (4)	0.020 (4)	0.030 (4)	0.002 (3)	−0.009 (4)	0.001 (3)
K1	0.0122 (13)	0.0247 (15)	0.0146 (14)	0.0005 (12)	0.0004 (11)	−0.0033 (12)
K2	0.0137 (13)	0.0129 (13)	0.0156 (15)	0.000	0.0020 (11)	0.000
K3	0.0415 (14)	0.0177 (11)	0.0267 (13)	0.0063 (10)	−0.0079 (10)	0.0047 (9)
K4	0.0236 (11)	0.0313 (12)	0.0191 (11)	−0.0039 (10)	−0.0073 (9)	0.0081 (9)
K5	0.0112 (10)	0.0312 (12)	0.0356 (13)	0.0031 (9)	0.0034 (9)	0.0229 (10)
K6	0.0200 (10)	0.0148 (10)	0.0153 (10)	−0.0001 (8)	−0.0005 (8)	−0.0020 (8)
K7	0.0136 (10)	0.0201 (10)	0.0137 (10)	−0.0032 (8)	−0.0024 (8)	−0.0001 (8)

Geometric parameters (Å, º)

Nb1—Se18	2.3473 (12)	Se16—K6^viii	3.191 (2)
Nb1—Se20	2.520 (7)	Se16—K7^vii	3.307 (2)
Nb1—Se12	2.5732 (11)	Se16—K4	3.364 (2)
Nb1—Se1	2.5890 (11)	Se15—Se14^i	2.6387 (9)
Nb1—Se2	2.6059 (10)	Se15—Nb2^i	2.6853 (11)
Nb1—Se7	2.6169 (11)	Se17—K6^x	3.110 (2)
Nb1—Se19	2.624 (7)	Se17—K7^vii	3.456 (2)
Nb1—Se9	2.6781 (11)	Se17—K2^ix	3.5863 (10)
Nb1—Se5	2.9281 (11)	Se17—K4^vii	3.814 (2)
Nb2—Se17	2.3523 (11)	Se17—K4^x	3.934 (2)
Nb2—Se14	2.5808 (11)	Se18—Se20	0.935 (8)
Nb2—Se4	2.5913 (11)	Se18—Se19	1.415 (7)
Nb2—Se8	2.5974 (11)	Se18—K1^v	3.1619 (10)
Nb2—Se10	2.6222 (11)	Se18—K3^v	3.550 (3)
Nb2—Se15	2.6852 (11)	Se18—K3	3.644 (3)
Nb2—Se8^i	2.8803 (11)	Se18—K5	3.791 (3)
Nb3—Se11	2.3713 (11)	Se19—Se20	2.347 (11)
Nb3—Se6	2.5678 (10)	Se19—K3^v	2.862 (7)
Nb3—Se5	2.5819 (10)	Se19—K3	3.084 (7)
Nb3—Se13	2.6214 (11)	Se19—K1^v	3.584 (7)
Nb3—Se3	2.6240 (10)	Se20—K5	3.300 (8)
Nb3—Se9	2.6747 (10)	Se20—K1^v	3.301 (7)
Nb3—Se2	2.9467 (11)	K1—Se18^ii	3.1619 (10)
Se1—Se9	2.5794 (11)	K1—Se18^iii	3.1619 (10)
Se1—K5^ii	3.319 (2)	K1—Se7^xii	3.2512 (8)
Se1—K1	3.4106 (8)	K1—Se20^ii	3.301 (7)
Se1—K3^iii	3.411 (2)	K1—Se20^iii	3.301 (7)
Se2—Se12	2.3720 (11)	K1—Se12^vi	3.3309 (8)
Se2—K5^iv	3.592 (2)	K1—Se12^xiii	3.3309 (8)
Se2—K3^v	3.756 (2)	K1—Se1^xii	3.4106 (8)
Se3—Se5	2.3833 (11)	K1—Se19^ii	3.584 (7)
Se3—K5^iv	3.402 (2)	K1—Se19^iii	3.584 (7)
Se3—K7^ii	3.422 (2)	K2—Se10^xiv	3.294 (2)
Se3—K3^vi	3.798 (2)	K2—Se10^xiii	3.294 (2)
Se4—Se16	2.3879 (12)	K2—Se8^iv	3.377 (2)
Se4—K6^vii	3.098 (2)	K2—Se8^xv	3.377 (2)
Se4—K7^vii	3.598 (2)	K2—Se14^ii	3.4471 (9)
Se4—K4	3.853 (2)	K2—Se14^xvi	3.4471 (9)
Se5—K5^ii	3.414 (2)	K2—Se17^iv	3.5862 (10)
Se5—K3^vi	3.560 (2)	K2—Se17^xv	3.5862 (10)
Se6—Se9	2.6269 (11)	K3—Se19^iii	2.862 (7)
Se6—K6^viii	3.206 (2)	K3—Se1^v	3.411 (2)
Se6—K5	3.265 (2)	K3—Se12^vi	3.537 (2)
Se6—K7	3.389 (2)	K3—Se18^iii	3.550 (3)
Se7—Se7^vi	2.3903 (16)	K3—Se5^vi	3.560 (2)
Se7—K1	3.2512 (8)	K3—Se7^vi	3.571 (2)
Se7—K3	3.421 (2)	K3—Se12^iii	3.716 (2)
Se7—K3^vi	3.571 (2)	K3—Se2^iii	3.756 (2)
Se8—Se10	2.3624 (11)	K3—Se3^vi	3.798 (2)
Se8—Nb2^i	2.8803 (11)	K4—Se10^xiii	3.308 (2)
Se8—K2^ix	3.377 (2)	K4—Se14^iv	3.394 (2)
Se9—K7	3.467 (2)	K4—Se17^xiii	3.814 (2)
Se9—K5	3.809 (2)	K4—Se17^iv	3.934 (2)
Se10—K2^vii	3.294 (2)	K5—Se1^viii	3.319 (2)
Se10—K4^vii	3.308 (2)	K5—Se3^x	3.402 (2)
Se11—K6	3.424 (2)	K5—Se5^viii	3.414 (2)
Se11—K7	3.450 (2)	K5—Se12^x	3.434 (2)
Se11—K4	3.507 (2)	K5—Se2^x	3.592 (2)
Se11—K7^ii	3.549 (2)	K5—Se13^x	3.742 (2)
Se11—K5^ii	3.827 (2)	K5—Se11^viii	3.827 (2)
Se12—K1^vii	3.3309 (8)	K6—Se4^xiii	3.098 (2)
Se12—K5^iv	3.434 (2)	K6—Se17^iv	3.110 (2)
Se12—K3^vi	3.537 (2)	K6—Se16^ii	3.191 (2)
Se12—K3^v	3.716 (2)	K6—Se6^ii	3.206 (2)
Se13—Se16	2.3912 (12)	K6—Se13^xiii	3.213 (2)
Se13—K6^vii	3.213 (2)	K6—Se14^ii	3.442 (2)
Se13—K4	3.539 (2)	K7—Se16^xiii	3.307 (2)
Se13—K5^iv	3.742 (2)	K7—Se3^viii	3.422 (2)
Se14—Se15	2.6386 (8)	K7—Se17^xiii	3.456 (2)
Se14—K4^x	3.394 (2)	K7—Se11^viii	3.549 (2)
Se14—K6^viii	3.442 (2)	K7—Se4^xiii	3.598 (2)
Se14—K2^xi	3.4470 (9)
Se18—Nb1—Se20	21.78 (18)	Nb1—Se20—K5	104.4 (2)
Se18—Nb1—Se12	106.52 (5)	Se18—Se20—K1^v	73.3 (4)
Se20—Nb1—Se12	125.86 (18)	Se19—Se20—K1^v	76.7 (3)
Se18—Nb1—Se1	104.71 (4)	Nb1—Se20—K1^v	141.7 (3)
Se20—Nb1—Se1	88.44 (18)	K5—Se20—K1^v	95.10 (18)
Se12—Nb1—Se1	144.27 (4)	Se18^ii—K1—Se18^iii	180.00 (4)
Se18—Nb1—Se2	101.08 (4)	Se18^ii—K1—Se7	86.13 (3)
Se20—Nb1—Se2	103.49 (17)	Se18^iii—K1—Se7	93.87 (3)
Se12—Nb1—Se2	54.51 (3)	Se18^ii—K1—Se7^xii	93.88 (3)
Se1—Nb1—Se2	134.00 (4)	Se18^iii—K1—Se7^xii	86.12 (3)
Se18—Nb1—Se7	101.86 (4)	Se7—K1—Se7^xii	180.0
Se20—Nb1—Se7	111.64 (17)	Se18^ii—K1—Se20^ii	16.46 (14)
Se12—Nb1—Se7	82.86 (3)	Se18^iii—K1—Se20^ii	163.54 (14)
Se1—Nb1—Se7	74.10 (3)	Se7—K1—Se20^ii	72.14 (14)
Se2—Nb1—Se7	135.83 (4)	Se7^xii—K1—Se20^ii	107.87 (14)
Se18—Nb1—Se19	32.47 (15)	Se18^ii—K1—Se20^iii	163.54 (14)
Se20—Nb1—Se19	54.2 (2)	Se18^iii—K1—Se20^iii	16.46 (14)
Se12—Nb1—Se19	77.60 (15)	Se7—K1—Se20^iii	107.86 (14)
Se1—Nb1—Se19	125.32 (15)	Se7^xii—K1—Se20^iii	72.13 (14)
Se2—Nb1—Se19	96.12 (15)	Se20^ii—K1—Se20^iii	180.0 (3)
Se7—Nb1—Se19	83.99 (15)	Se18^ii—K1—Se12^vi	99.80 (2)
Se18—Nb1—Se9	99.44 (4)	Se18^iii—K1—Se12^vi	80.20 (2)
Se20—Nb1—Se9	78.59 (19)	Se7—K1—Se12^vi	59.97 (2)
Se12—Nb1—Se9	130.77 (4)	Se7^xii—K1—Se12^vi	120.03 (2)
Se1—Nb1—Se9	58.62 (3)	Se20^ii—K1—Se12^vi	99.32 (13)
Se2—Nb1—Se9	80.14 (3)	Se20^iii—K1—Se12^vi	80.68 (13)
Se7—Nb1—Se9	131.63 (4)	Se18^ii—K1—Se12^xiii	80.20 (2)
Se19—Nb1—Se9	130.66 (14)	Se18^iii—K1—Se12^xiii	99.80 (2)
Se18—Nb1—Se5	170.25 (5)	Se7—K1—Se12^xiii	120.03 (2)
Se20—Nb1—Se5	148.76 (19)	Se7^xii—K1—Se12^xiii	59.97 (2)
Se12—Nb1—Se5	83.12 (3)	Se20^ii—K1—Se12^xiii	80.68 (13)
Se1—Nb1—Se5	66.59 (3)	Se20^iii—K1—Se12^xiii	99.32 (13)
Se2—Nb1—Se5	83.22 (3)	Se12^vi—K1—Se12^xiii	180.00 (3)
Se7—Nb1—Se5	80.42 (3)	Se18^ii—K1—Se1	86.30 (3)
Se19—Nb1—Se5	156.52 (14)	Se18^iii—K1—Se1	93.70 (3)
Se9—Nb1—Se5	72.51 (3)	Se7—K1—Se1	56.12 (2)
Se17—Nb2—Se14	103.13 (4)	Se7^xii—K1—Se1	123.88 (2)
Se17—Nb2—Se4	101.69 (4)	Se20^ii—K1—Se1	71.47 (14)
Se14—Nb2—Se4	87.24 (3)	Se20^iii—K1—Se1	108.53 (14)
Se17—Nb2—Se8	101.59 (4)	Se12^vi—K1—Se1	115.124 (19)
Se14—Nb2—Se8	134.66 (4)	Se12^xiii—K1—Se1	64.876 (19)
Se4—Nb2—Se8	123.75 (4)	Se18^ii—K1—Se1^xii	93.70 (3)
Se17—Nb2—Se10	103.67 (4)	Se18^iii—K1—Se1^xii	86.30 (3)
Se14—Nb2—Se10	148.39 (4)	Se7—K1—Se1^xii	123.88 (2)
Se4—Nb2—Se10	71.16 (3)	Se7^xii—K1—Se1^xii	56.12 (2)
Se8—Nb2—Se10	53.82 (3)	Se20^ii—K1—Se1^xii	108.53 (14)
Se17—Nb2—Se15	99.91 (4)	Se20^iii—K1—Se1^xii	71.47 (14)
Se14—Nb2—Se15	60.10 (3)	Se12^vi—K1—Se1^xii	64.876 (19)
Se4—Nb2—Se15	144.19 (4)	Se12^xiii—K1—Se1^xii	115.124 (19)
Se8—Nb2—Se15	78.63 (3)	Se1—K1—Se1^xii	179.999 (15)
Se10—Nb2—Se15	129.97 (4)	Se18^ii—K1—Se19^ii	23.15 (11)
Se17—Nb2—Se8^i	170.54 (4)	Se18^iii—K1—Se19^ii	156.85 (11)
Se14—Nb2—Se8^i	67.69 (3)	Se7—K1—Se19^ii	105.21 (11)
Se4—Nb2—Se8^i	80.62 (3)	Se7^xii—K1—Se19^ii	74.79 (11)
Se8—Nb2—Se8^i	84.35 (3)	Se20^ii—K1—Se19^ii	39.59 (18)
Se10—Nb2—Se8^i	85.76 (3)	Se20^iii—K1—Se19^ii	140.41 (18)
Se15—Nb2—Se8^i	73.86 (3)	Se12^vi—K1—Se19^ii	97.91 (11)
Se11—Nb3—Se6	104.08 (4)	Se12^xiii—K1—Se19^ii	82.09 (11)
Se11—Nb3—Se5	100.27 (4)	Se1—K1—Se19^ii	107.71 (11)
Se6—Nb3—Se5	134.41 (4)	Se1^xii—K1—Se19^ii	72.29 (11)
Se11—Nb3—Se13	101.72 (4)	Se18^ii—K1—Se19^iii	156.85 (11)
Se6—Nb3—Se13	84.42 (3)	Se18^iii—K1—Se19^iii	23.15 (11)
Se5—Nb3—Se13	127.25 (4)	Se7—K1—Se19^iii	74.79 (11)
Se11—Nb3—Se3	103.09 (4)	Se7^xii—K1—Se19^iii	105.21 (11)
Se6—Nb3—Se3	148.14 (4)	Se20^ii—K1—Se19^iii	140.41 (18)
Se5—Nb3—Se3	54.48 (3)	Se20^iii—K1—Se19^iii	39.59 (18)
Se13—Nb3—Se3	74.02 (3)	Se12^vi—K1—Se19^iii	82.09 (11)
Se11—Nb3—Se9	99.50 (4)	Se12^xiii—K1—Se19^iii	97.91 (11)
Se6—Nb3—Se9	60.10 (3)	Se1—K1—Se19^iii	72.29 (11)
Se5—Nb3—Se9	78.35 (3)	Se1^xii—K1—Se19^iii	107.71 (11)
Se13—Nb3—Se9	142.16 (4)	Se19^ii—K1—Se19^iii	180.0 (3)
Se3—Nb3—Se9	130.31 (4)	Se10^xiv—K2—Se10^xiii	73.64 (6)
Se11—Nb3—Se2	172.22 (4)	Se10^xiv—K2—Se8^iv	145.93 (2)
Se6—Nb3—Se2	68.88 (3)	Se10^xiii—K2—Se8^iv	108.05 (2)
Se5—Nb3—Se2	83.26 (3)	Se10^xiv—K2—Se8^xv	108.05 (2)
Se13—Nb3—Se2	81.25 (3)	Se10^xiii—K2—Se8^xv	145.93 (2)
Se3—Nb3—Se2	84.62 (3)	Se8^iv—K2—Se8^xv	89.38 (7)
Se9—Nb3—Se2	74.30 (3)	Se10^xiv—K2—Se14^ii	85.44 (4)
Se9—Se1—Nb1	62.42 (3)	Se10^xiii—K2—Se14^ii	94.04 (4)
Se9—Se1—K5^ii	92.30 (5)	Se8^iv—K2—Se14^ii	127.47 (6)
Nb1—Se1—K5^ii	125.82 (5)	Se8^xv—K2—Se14^ii	53.12 (2)
Se9—Se1—K1	173.81 (4)	Se10^xiv—K2—Se14^xvi	94.04 (4)
Nb1—Se1—K1	111.58 (3)	Se10^xiii—K2—Se14^xvi	85.44 (4)
K5^ii—Se1—K1	92.73 (5)	Se8^iv—K2—Se14^xvi	53.12 (2)
Se9—Se1—K3^iii	100.27 (5)	Se8^xv—K2—Se14^xvi	127.47 (6)
Nb1—Se1—K3^iii	116.85 (5)	Se14^ii—K2—Se14^xvi	179.35 (9)
K5^ii—Se1—K3^iii	114.28 (6)	Se10^xiv—K2—Se17^iv	133.98 (7)
K1—Se1—K3^iii	80.92 (4)	Se10^xiii—K2—Se17^iv	62.69 (3)
Se12—Se2—Nb1	62.04 (3)	Se8^iv—K2—Se17^iv	66.83 (3)
Se12—Se2—Nb3	112.83 (4)	Se8^xv—K2—Se17^iv	100.61 (5)
Nb1—Se2—Nb3	84.29 (3)	Se14^ii—K2—Se17^iv	83.87 (2)
Se12—Se2—K5^iv	66.71 (5)	Se14^xvi—K2—Se17^iv	96.22 (2)
Nb1—Se2—K5^iv	122.38 (5)	Se10^xiv—K2—Se17^xv	62.69 (3)
Nb3—Se2—K5^iv	92.81 (4)	Se10^xiii—K2—Se17^xv	133.98 (7)
Se12—Se2—K3^v	70.57 (4)	Se8^iv—K2—Se17^xv	100.61 (5)
Nb1—Se2—K3^v	86.05 (4)	Se8^xv—K2—Se17^xv	66.83 (3)
Nb3—Se2—K3^v	166.30 (5)	Se14^ii—K2—Se17^xv	96.22 (2)
K5^iv—Se2—K3^v	100.57 (5)	Se14^xvi—K2—Se17^xv	83.87 (2)
Se5—Se3—Nb3	61.86 (3)	Se17^iv—K2—Se17^xv	163.07 (9)
Se5—Se3—K5^iv	120.19 (5)	Se19^iii—K3—Se19	96.83 (10)
Nb3—Se3—K5^iv	103.49 (5)	Se19^iii—K3—Se1^v	116.36 (15)
Se5—Se3—K7^ii	104.03 (4)	Se19—K3—Se1^v	78.74 (13)
Nb3—Se3—K7^ii	92.79 (4)	Se19^iii—K3—Se7	82.39 (15)
K5^iv—Se3—K7^ii	135.55 (5)	Se19—K3—Se7	65.01 (13)
Se5—Se3—K3^vi	65.76 (4)	Se1^v—K3—Se7	141.30 (8)
Nb3—Se3—K3^vi	122.30 (5)	Se19^iii—K3—Se12^vi	89.87 (14)
K5^iv—Se3—K3^vi	82.84 (6)	Se19—K3—Se12^vi	119.45 (14)
K7^ii—Se3—K3^vi	122.39 (5)	Se1^v—K3—Se12^vi	147.20 (7)
Se16—Se4—Nb2	114.43 (4)	Se7—K3—Se12^vi	56.42 (4)
Se16—Se4—K6^vii	101.81 (5)	Se19^iii—K3—Se18^iii	22.38 (13)
Nb2—Se4—K6^vii	143.58 (5)	Se19—K3—Se18^iii	117.33 (14)
Se16—Se4—K7^vii	63.34 (4)	Se1^v—K3—Se18^iii	126.15 (7)
Nb2—Se4—K7^vii	89.56 (4)	Se7—K3—Se18^iii	84.45 (5)
K6^vii—Se4—K7^vii	104.08 (5)	Se12^vi—K3—Se18^iii	72.37 (5)
Se16—Se4—K4	59.89 (4)	Se19^iii—K3—Se5^vi	146.12 (15)
Nb2—Se4—K4	119.00 (5)	Se19—K3—Se5^vi	113.00 (14)
K6^vii—Se4—K4	81.80 (5)	Se1^v—K3—Se5^vi	86.13 (5)
K7^vii—Se4—K4	122.85 (5)	Se7—K3—Se5^vi	95.53 (6)
Se3—Se5—Nb3	63.66 (3)	Se12^vi—K3—Se5^vi	62.08 (4)
Se3—Se5—Nb1	115.59 (4)	Se18^iii—K3—Se5^vi	123.81 (7)
Nb3—Se5—Nb1	85.09 (3)	Se19^iii—K3—Se7^vi	121.99 (15)
Se3—Se5—K5^ii	125.66 (5)	Se19—K3—Se7^vi	68.37 (13)
Nb3—Se5—K5^ii	97.09 (5)	Se1^v—K3—Se7^vi	114.81 (7)
Nb1—Se5—K5^ii	112.19 (4)	Se7—K3—Se7^vi	39.91 (3)
Se3—Se5—K3^vi	76.62 (5)	Se12^vi—K3—Se7^vi	57.78 (4)
Nb3—Se5—K3^vi	133.36 (5)	Se18^iii—K3—Se7^vi	118.88 (6)
Nb1—Se5—K3^vi	91.29 (4)	Se5^vi—K3—Se7^vi	60.40 (4)
K5^ii—Se5—K3^vi	126.70 (6)	Se19^iii—K3—Se18	74.76 (14)
Nb3—Se6—Se9	61.97 (3)	Se19—K3—Se18	22.36 (13)
Nb3—Se6—K6^viii	137.12 (5)	Se1^v—K3—Se18	85.64 (5)
Se9—Se6—K6^viii	144.67 (5)	Se7—K3—Se18	66.11 (5)
Nb3—Se6—K5	132.71 (5)	Se12^vi—K3—Se18	121.97 (6)
Se9—Se6—K5	79.76 (5)	Se18^iii—K3—Se18	96.01 (6)
K6^viii—Se6—K5	90.16 (6)	Se5^vi—K3—Se18	135.14 (7)
Nb3—Se6—K7	88.04 (4)	Se7^vi—K3—Se18	83.78 (5)
Se9—Se6—K7	69.05 (4)	Se19^iii—K3—Se12^iii	57.62 (14)
K6^viii—Se6—K7	80.98 (5)	Se19—K3—Se12^iii	99.82 (13)
K5—Se6—K7	103.95 (5)	Se1^v—K3—Se12^iii	60.81 (4)
Se7^vi—Se7—Nb1	108.89 (5)	Se7—K3—Se12^iii	136.05 (7)
Se7^vi—Se7—K1	133.45 (5)	Se12^vi—K3—Se12^iii	132.33 (7)
Nb1—Se7—K1	115.82 (3)	Se18^iii—K3—Se12^iii	65.73 (5)
Se7^vi—Se7—K3	73.44 (5)	Se5^vi—K3—Se12^iii	127.57 (6)
Nb1—Se7—K3	96.20 (5)	Se7^vi—K3—Se12^iii	168.18 (8)
K1—Se7—K3	89.16 (4)	Se18—K3—Se12^iii	84.90 (5)
Se7^vi—Se7—K3^vi	66.65 (5)	Se19^iii—K3—Se2^iii	70.54 (15)
Nb1—Se7—K3^vi	96.50 (5)	Se19—K3—Se2^iii	135.65 (14)
K1—Se7—K3^vi	118.31 (4)	Se1^v—K3—Se2^iii	70.62 (4)
K3—Se7—K3^vi	140.09 (3)	Se7—K3—Se2^iii	146.67 (7)
Se10—Se8—Nb2	63.63 (3)	Se12^vi—K3—Se2^iii	103.29 (6)
Se10—Se8—Nb2^i	114.96 (4)	Se18^iii—K3—Se2^iii	63.12 (4)
Nb2—Se8—Nb2^i	84.66 (3)	Se5^vi—K3—Se2^iii	96.39 (6)
Se10—Se8—K2^ix	121.67 (4)	Se7^vi—K3—Se2^iii	154.41 (7)
Nb2—Se8—K2^ix	91.88 (3)	Se18—K3—Se2^iii	121.81 (6)
Nb2^i—Se8—K2^ix	114.02 (4)	Se12^iii—K3—Se2^iii	37.02 (3)
Se1—Se9—Se6	164.62 (4)	Se19^iii—K3—Se3^vi	115.20 (15)
Se1—Se9—Nb3	109.43 (4)	Se19—K3—Se3^vi	147.93 (14)
Se6—Se9—Nb3	57.93 (3)	Se1^v—K3—Se3^vi	85.20 (5)
Se1—Se9—Nb1	58.97 (3)	Se7—K3—Se3^vi	118.68 (6)
Se6—Se9—Nb1	109.32 (4)	Se12^vi—K3—Se3^vi	65.00 (4)
Nb3—Se9—Nb1	88.48 (3)	Se18^iii—K3—Se3^vi	94.57 (6)
Se1—Se9—K7	124.68 (5)	Se5^vi—K3—Se3^vi	37.62 (3)
Se6—Se9—K7	65.92 (4)	Se7^vi—K3—Se3^vi	94.28 (5)
Nb3—Se9—K7	84.78 (4)	Se18—K3—Se3^vi	168.82 (7)
Nb1—Se9—K7	173.15 (5)	Se12^iii—K3—Se3^vi	96.18 (5)
Se1—Se9—K5	127.57 (5)	Se2^iii—K3—Se3^vi	60.57 (4)
Se6—Se9—K5	57.51 (4)	Se10^xiii—K4—Se16	148.87 (8)
Nb3—Se9—K5	109.98 (4)	Se10^xiii—K4—Se14^iv	97.21 (6)
Nb1—Se9—K5	89.11 (4)	Se16—K4—Se14^iv	107.54 (6)
K7—Se9—K5	92.06 (5)	Se10^xiii—K4—Se11	93.48 (6)
Se8—Se10—Nb2	62.55 (3)	Se16—K4—Se11	92.15 (5)
Se8—Se10—K2^vii	108.09 (4)	Se14^iv—K4—Se11	116.38 (7)
Nb2—Se10—K2^vii	131.43 (4)	Se10^xiii—K4—Se13	160.15 (8)
Se8—Se10—K4^vii	106.38 (5)	Se16—K4—Se13	40.43 (3)
Nb2—Se10—K4^vii	98.28 (5)	Se14^iv—K4—Se13	90.66 (5)
K2^vii—Se10—K4^vii	128.50 (5)	Se11—K4—Se13	66.74 (4)
Nb3—Se11—K6	164.87 (5)	Se10^xiii—K4—Se17^xiii	66.24 (4)
Nb3—Se11—K7	89.85 (4)	Se16—K4—Se17^xiii	83.51 (5)
K6—Se11—K7	100.58 (5)	Se14^iv—K4—Se17^xiii	152.79 (7)
Nb3—Se11—K4	95.38 (5)	Se11—K4—Se17^xiii	87.18 (5)
K6—Se11—K4	95.34 (5)	Se13—K4—Se17^xiii	112.24 (6)
K7—Se11—K4	91.14 (5)	Se10^xiii—K4—Se4	144.07 (7)
Nb3—Se11—K7^ii	94.27 (4)	Se16—K4—Se4	37.88 (3)
K6—Se11—K7^ii	75.81 (5)	Se14^iv—K4—Se4	73.27 (4)
K7—Se11—K7^ii	175.32 (7)	Se11—K4—Se4	122.02 (6)
K4—Se11—K7^ii	86.27 (5)	Se13—K4—Se4	55.75 (3)
Nb3—Se11—K5^ii	90.70 (4)	Se17^xiii—K4—Se4	106.85 (6)
K6—Se11—K5^ii	78.17 (5)	Se10^xiii—K4—Se17^iv	58.64 (4)
K7—Se11—K5^ii	91.66 (5)	Se16—K4—Se17^iv	150.61 (7)
K4—Se11—K5^ii	173.31 (5)	Se14^iv—K4—Se17^iv	63.19 (4)
K7^ii—Se11—K5^ii	90.51 (5)	Se11—K4—Se17^iv	70.58 (4)
Se2—Se12—Nb1	63.45 (3)	Se13—K4—Se17^iv	110.20 (6)
Se2—Se12—K1^vii	142.13 (4)	Se17^xiii—K4—Se17^iv	117.89 (5)
Nb1—Se12—K1^vii	138.01 (3)	Se4—K4—Se17^iv	134.43 (6)
Se2—Se12—K5^iv	73.91 (5)	Se6—K5—Se20	93.30 (13)
Nb1—Se12—K5^iv	129.77 (5)	Se6—K5—Se1^viii	148.73 (7)
K1^vii—Se12—K5^iv	92.10 (4)	Se20—K5—Se1^viii	72.64 (13)
Se2—Se12—K3^vi	126.73 (5)	Se6—K5—Se3^x	76.77 (5)
Nb1—Se12—K3^vi	98.17 (5)	Se20—K5—Se3^x	109.55 (16)
K1^vii—Se12—K3^vi	85.97 (4)	Se1^viii—K5—Se3^x	133.96 (6)
K5^iv—Se12—K3^vi	86.41 (6)	Se6—K5—Se5^viii	95.07 (5)
Se2—Se12—K3^v	72.42 (5)	Se20—K5—Se5^viii	63.47 (15)
Nb1—Se12—K3^v	87.36 (4)	Se1^viii—K5—Se5^viii	53.69 (4)
K1^vii—Se12—K3^v	77.62 (4)	Se3^x—K5—Se5^viii	169.28 (8)
K5^iv—Se12—K3^v	104.44 (5)	Se6—K5—Se12^x	141.37 (7)
K3^vi—Se12—K3^v	160.52 (7)	Se20—K5—Se12^x	79.18 (14)
Se16—Se13—Nb3	107.99 (4)	Se1^viii—K5—Se12^x	64.73 (4)
Se16—Se13—K6^vii	98.54 (5)	Se3^x—K5—Se12^x	70.53 (4)
Nb3—Se13—K6^vii	148.61 (5)	Se5^viii—K5—Se12^x	114.21 (6)
Se16—Se13—K4	65.85 (5)	Se6—K5—Se2^x	136.37 (7)
Nb3—Se13—K4	90.27 (4)	Se20—K5—Se2^x	118.03 (14)
K6^vii—Se13—K4	85.44 (5)	Se1^viii—K5—Se2^x	73.72 (4)
Se16—Se13—K5^iv	126.09 (5)	Se3^x—K5—Se2^x	64.92 (4)
Nb3—Se13—K5^iv	95.12 (4)	Se5^viii—K5—Se2^x	125.12 (6)
K6^vii—Se13—K5^iv	82.04 (5)	Se12^x—K5—Se2^x	39.38 (3)
K4—Se13—K5^iv	163.86 (5)	Se6—K5—Se13^x	81.17 (5)
Nb2—Se14—Se15	61.91 (3)	Se20—K5—Se13^x	161.64 (16)
Nb2—Se14—K4^x	100.30 (5)	Se1^viii—K5—Se13^x	120.16 (7)
Se15—Se14—K4^x	85.32 (5)	Se3^x—K5—Se13^x	52.19 (3)
Nb2—Se14—K6^viii	136.67 (5)	Se5^viii—K5—Se13^x	134.18 (7)
Se15—Se14—K6^viii	160.28 (5)	Se12^x—K5—Se13^x	94.19 (5)
K4^x—Se14—K6^viii	84.28 (5)	Se2^x—K5—Se13^x	59.36 (4)
Nb2—Se14—K2^xi	120.66 (5)	Se6—K5—Se18	94.26 (6)
Se15—Se14—K2^xi	85.76 (2)	Se20—K5—Se18	12.92 (14)
K4^x—Se14—K2^xi	126.73 (6)	Se1^viii—K5—Se18	78.19 (5)
K6^viii—Se14—K2^xi	87.11 (4)	Se3^x—K5—Se18	97.19 (6)
Se4—Se16—Se13	93.03 (4)	Se5^viii—K5—Se18	76.26 (5)
Se4—Se16—K6^viii	130.05 (5)	Se12^x—K5—Se18	70.57 (5)
Se13—Se16—K6^viii	132.92 (5)	Se2^x—K5—Se18	109.95 (6)
Se4—Se16—K7^vii	76.48 (5)	Se13^x—K5—Se18	149.34 (6)
Se13—Se16—K7^vii	100.45 (5)	Se6—K5—Se9	42.73 (3)
K6^viii—Se16—K7^vii	106.78 (5)	Se20—K5—Se9	54.64 (13)
Se4—Se16—K4	82.23 (5)	Se1^viii—K5—Se9	110.42 (6)
Se13—Se16—K4	73.71 (5)	Se3^x—K5—Se9	106.35 (6)
K6^viii—Se16—K4	92.08 (5)	Se5^viii—K5—Se9	63.10 (4)
K7^vii—Se16—K4	157.64 (6)	Se12^x—K5—Se9	130.52 (7)
Se14—Se15—Se14^i	163.65 (6)	Se2^x—K5—Se9	167.35 (7)
Se14—Se15—Nb2	57.99 (3)	Se13^x—K5—Se9	123.66 (6)
Se14^i—Se15—Nb2	108.89 (4)	Se18—K5—Se9	60.69 (4)
Se14—Se15—Nb2^i	108.89 (4)	Se6—K5—Se11^viii	71.73 (4)
Se14^i—Se15—Nb2^i	57.99 (3)	Se20—K5—Se11^viii	122.41 (15)
Nb2—Se15—Nb2^i	86.93 (4)	Se1^viii—K5—Se11^viii	92.03 (5)
Nb2—Se17—K6^x	175.88 (6)	Se3^x—K5—Se11^viii	119.47 (6)
Nb2—Se17—K7^vii	97.21 (5)	Se5^viii—K5—Se11^viii	63.08 (4)
K6^x—Se17—K7^vii	81.30 (5)	Se12^x—K5—Se11^viii	143.36 (7)
Nb2—Se17—K2^ix	91.12 (4)	Se2^x—K5—Se11^viii	109.19 (6)
K6^x—Se17—K2^ix	90.00 (4)	Se13^x—K5—Se11^viii	72.61 (5)
K7^vii—Se17—K2^ix	169.89 (4)	Se18—K5—Se11^viii	134.82 (6)
Nb2—Se17—K4^vii	90.76 (4)	Se9—K5—Se11^viii	82.91 (4)
K6^x—Se17—K4^vii	85.32 (5)	Se4^xiii—K6—Se17^iv	99.42 (6)
K7^vii—Se17—K4^vii	86.09 (5)	Se4^xiii—K6—Se16^ii	143.74 (7)
K2^ix—Se17—K4^vii	88.10 (5)	Se17^iv—K6—Se16^ii	99.03 (6)
Nb2—Se17—K4^x	90.94 (4)	Se4^xiii—K6—Se6^ii	146.23 (7)
K6^x—Se17—K4^x	92.61 (5)	Se17^iv—K6—Se6^ii	97.19 (6)
K7^vii—Se17—K4^x	81.24 (5)	Se16^ii—K6—Se6^ii	60.22 (4)
K2^ix—Se17—K4^x	104.42 (5)	Se4^xiii—K6—Se13^xiii	66.62 (4)
K4^vii—Se17—K4^x	167.33 (7)	Se17^iv—K6—Se13^xiii	163.27 (7)
Se20—Se18—Se19	173.6 (5)	Se16^ii—K6—Se13^xiii	97.70 (6)
Se20—Se18—Nb1	89.5 (4)	Se6^ii—K6—Se13^xiii	90.87 (5)
Se19—Se18—Nb1	84.6 (3)	Se4^xiii—K6—Se11	75.21 (5)
Se20—Se18—K1^v	90.2 (4)	Se17^iv—K6—Se11	82.47 (5)
Se19—Se18—K1^v	95.4 (3)	Se16^ii—K6—Se11	138.23 (7)
Nb1—Se18—K1^v	175.71 (5)	Se6^ii—K6—Se11	78.10 (5)
Se20—Se18—K3^v	133.1 (5)	Se13^xiii—K6—Se11	84.90 (5)
Se19—Se18—K3^v	50.3 (3)	Se4^xiii—K6—Se14^ii	82.98 (5)
Nb1—Se18—K3^v	94.94 (5)	Se17^iv—K6—Se14^ii	91.58 (5)
K1^v—Se18—K3^v	88.33 (4)	Se16^ii—K6—Se14^ii	65.56 (4)
Se20—Se18—K3	122.3 (5)	Se6^ii—K6—Se14^ii	125.78 (6)
Se19—Se18—K3	56.0 (3)	Se13^xiii—K6—Se14^ii	95.57 (5)
Nb1—Se18—K3	95.69 (5)	Se11—K6—Se14^ii	156.04 (6)
K1^v—Se18—K3	80.81 (4)	Se16^xiii—K7—Se6	162.28 (7)
K3^v—Se18—K3	103.66 (6)	Se16^xiii—K7—Se3^viii	86.49 (5)
Se20—Se18—K5	52.1 (5)	Se6—K7—Se3^viii	103.50 (5)
Se19—Se18—K5	130.9 (3)	Se16^xiii—K7—Se11	92.86 (5)
Nb1—Se18—K5	94.78 (5)	Se6—K7—Se11	69.44 (4)
K1^v—Se18—K5	88.46 (4)	Se3^viii—K7—Se11	128.37 (6)
K3^v—Se18—K5	81.03 (5)	Se16^xiii—K7—Se17^xiii	94.88 (5)
K3—Se18—K5	168.09 (6)	Se6—K7—Se17^xiii	87.60 (5)
Se18—Se19—Se20	2.6 (2)	Se3^viii—K7—Se17^xiii	137.50 (6)
Se18—Se19—Nb1	62.9 (2)	Se11—K7—Se17^xiii	94.05 (5)
Se20—Se19—Nb1	60.6 (2)	Se16^xiii—K7—Se9	128.22 (6)
Se18—Se19—K3^v	107.3 (3)	Se6—K7—Se9	45.04 (3)
Se20—Se19—K3^v	108.7 (3)	Se3^viii—K7—Se9	72.62 (4)
Nb1—Se19—K3^v	107.3 (2)	Se11—K7—Se9	67.76 (4)
Se18—Se19—K3	101.7 (3)	Se17^xiii—K7—Se9	132.32 (6)
Se20—Se19—K3	101.1 (3)	Se16^xiii—K7—Se11^viii	123.57 (6)
Nb1—Se19—K3	104.6 (2)	Se6—K7—Se11^viii	74.06 (4)
K3^v—Se19—K3	144.0 (3)	Se3^viii—K7—Se11^viii	68.31 (4)
Se18—Se19—K1^v	61.4 (2)	Se11—K7—Se11^viii	142.53 (6)
Se20—Se19—K1^v	63.7 (2)	Se17^xiii—K7—Se11^viii	76.00 (4)
Nb1—Se19—K1^v	124.2 (2)	Se9—K7—Se11^viii	92.21 (5)
K3^v—Se19—K1^v	92.54 (17)	Se16^xiii—K7—Se4^xiii	40.19 (3)
K3—Se19—K1^v	82.83 (16)	Se6—K7—Se4^xiii	127.93 (6)
Se18—Se20—Se19	3.9 (3)	Se3^viii—K7—Se4^xiii	126.67 (6)
Se18—Se20—Nb1	68.7 (4)	Se11—K7—Se4^xiii	68.88 (4)
Se19—Se20—Nb1	65.2 (3)	Se17^xiii—K7—Se4^xiii	65.86 (4)
Se18—Se20—K5	115.0 (5)	Se9—K7—Se4^xiii	133.70 (6)
Se19—Se20—K5	116.9 (3)	Se11^viii—K7—Se4^xiii	133.05 (6)

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