Crystal structure of KNaCuP2O7, a new member of the diphosphate family.

Potassium sodium copper(II) diphosphate(V), KNaCuP2O7, was synthesized by solid-state reactions. It crystallizes in the α-Na2CuP2O7 structure type in space group P21/n. In the crystal, CuO5 square-pyramids are linked to nearly eclipsed P2O7 groups by sharing corners to build up corrugated layers with composition [CuP2O7]2- that extend parallel to (010). The K+ and Na+ cations reside in the inter-layer space and are connected to nine and seven O atoms, respectively. The structural model was validated by bond-valence-sum (BVS) and charge-distribution (CHARDI) analysis.

Chemical context

In order to improve the ionic conductivity in copper diphosphates with general formula MM’CuP2O7 (M, M’ = monovalent cation), we attempted to partially replace the potassium cations in K2CuP2O7 by smaller sodium cations. In the K2CuP2O7 structure, the alkali cations are located in the inter­layer space between corrugated [CuP2O7]2− anionic layers. Reducing the size of the cation can increase its mobility, and therefore might improve the material’s charge-transport behaviour.

Several attempts were made to prepare crystals of the hypothetical solid solution K2–NaCuP2O7, with x in the range 0 to 2. All of the attempts led to a compound with x = 1, i.e. KNaCuP2O7, the crystal structure of which is reported in this communication.

Structural commentary

The title compound KNaCuP2O7 crystallizes isotypically with α-Na2CuP2O7 (Erragh et al., 1995 ▸) and also shows resemblance with one form of K2CuP2O7 (ElMaadi et al., 1995 ▸). It is built up by corrugated [CuP2O7]2− layers with the alkali cations situated in the inter­layer space. The anionic layers consist of a nearly eclipsed diphosphate group [O2—P2—P1—O6 torsion angle = 15.90 (1)°] linked to CuO5 square-pyramids by sharing five of the terminal oxygen atoms (O2, O3, O5, O6, O7). The bridging atom O4 of the diphosphate unit is not involved in metal coordination, and atom O1 coordinates to the alkali cations in the inter­layer space (Fig. 1 ▸).

Figure 1

The diphosphate group directly connected to three CuO5 polyhedra in the structure of KNaCuP2O7. Displacement ellipsoids are drawn at the 50% probability level.

The P2—O4—P1 bridging angle [119.01 (11)°] of the diphosphate anion is close to those observed in other similar diarsenate and diphosphate structures, such as KCr1/4Al3/4As2O7 [118.50 (14)°; Bouhassine & Boughzala, 2017 ▸], CsCrAs2O7 [118.7 (2)°; Bouhassine & Boughzala, 2015 ▸], KAlAs2O7 [118.3 (2)°; Boughzala & Jouini, 1995 ▸], α-Na2CuP2O7 [118.65 (1)°; Erragh et al., 1995 ▸] and K2CuP2O7 [120.41 (3)°; ElMaadi et al., 1995 ▸]. As expected, the Cu—O bond length to the apical oxygen atom O5 is significantly longer than the Cu—O distances to the basal oxygen atoms of the square-pyramid (Table 1 ▸). The calculated bond-valence sum (Brown, 2002 ▸; Adams, 2003 ▸) of 1.94 valence units for the Cu site is in good agreement with the expected value of 2 for divalent copper. The geometry index of the CuO5 polyhedron τ 5, as defined by Addison et al. (1984 ▸), has a value of 0.26, indicating a distorted square-pyramidal coordination environment (the value for an ideal square-pyramid is 0 while that of an ideal trigonal bipyramid is 1). Each CuO5 polyhedron shares its vertices with two P2O7 4− anions, one of which is chelating and the other belongs to two different P2O7 groups (Fig. 2 ▸). This linkage leads to layers extending parallel to (010) (Fig. 3 ▸).

Table 1

Selected bond lengths (Å)

Cu—O2	1.9328 (18)	Na—O5	2.398 (2)
Cu—O3i	1.9427 (18)	Na—O7i	2.4442 (19)
Cu—O6	1.9743 (17)	Na—O3iv	2.772 (2)
Cu—O7i	1.9872 (17)	Na—O5i	2.815 (2)
Cu—O5ii	2.3225 (19)	Na—O7iv	2.878 (2)
P1—O1	1.482 (2)	K—O2	2.721 (2)
P1—O2	1.5246 (19)	K—O5iii	2.7245 (18)
P1—O3	1.5313 (19)	K—O1i	2.764 (2)
P1—O4	1.6272 (17)	K—O6v	2.7969 (19)
P2—O5	1.4958 (17)	K—O7vi	2.8450 (19)
P2—O6	1.5252 (17)	K—O3vii	2.8630 (18)
P2—O7	1.5277 (16)	K—O1	3.036 (2)
P2—O4	1.6148 (18)	K—O2vii	3.1973 (19)
Na—O1iii	2.249 (2)	K—O3i	3.257 (2)
Na—O6iv	2.397 (2)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) ; (v) ; (vi) ; (vii) .

Figure 2

The CuO5 square-pyramid with neighbouring diphosphate groups in the structure of KNaCuP2O7. Displacement ellipsoids are drawn at the 50% probability level.

Figure 3

Projection of the KNaCuP2O7 structure along [100], showing the corrugated inter­layer space housing the cations K+ in the ‘L’ sites and Na+ in the ‘S’ sites. Displacement ellipsoids are drawn at the 99% probability level.

As in the crystal structures of K2CuP2O7 and α-Na2CuP2O7, the crystal structure of KNaCuP2O7 exhibits two independent sites hosting the K+ and Na+ cations. The first site is larger (‘L’) and is occupied by K+ cations. It is limited by two neighbouring anionic layers (Fig. 3 ▸). The resulting KO9 coord­ination polyhedron is considerably distorted (Fig. 4 ▸, Table 1 ▸). Its bond-valence sum is 0.98 valence units (Table 2 ▸). The second site is smaller (‘S’) and is occupied by Na+ cations. It is surrounded by three CuO5 and five PO4 polyhedra, delimiting an ellipsoidal cavity as shown in Figs. 3 ▸ and 5 ▸. The irregular coordination sphere of Na+ is made up of seven oxygen atoms and shows an effective coordination number (ECoN; Nespolo et al., 2001 ▸) of 5.2 (for other ECoN values, see Table 2 ▸). The Na—O bonds lengths can be divided in groups of four short [2.249 (2)–2.4442 (19) Å] and three long [2.772 (2)–2.878 (2) Å] bonds (Table 1 ▸). Its bond-valence sum is 0.98 valence units (Table 2 ▸).

Figure 4

The nine-coordinated K+ cation in the large ‘L’ site within the inter­layer space in the structure of KNaCuP2O7. Displacement ellipsoids are drawn at 50% probability level. [Symmetry codes: (i) 1 + x, y, z; (ii) 1 − x, 1 − y, −z; (iii)  − x, − + y,  − z; (iv)  − x, − + y,  − z; (v) 1 − x, 1 − y, 1 − z.]

Table 2

CHARDI and BVS analysis of cation polyhedra in KNaCuP2O7

Cation	qi()·sof(i)	Q(i)	V(i)·sof(i)	CN(i)	ECoN(i)	d ar(i)	d med(i)
Cu	2.000	1.94	1.995	5	4.35	2.031	2.031
P1	5.000	5.07	4.921	4	3.84	1.540	1.541
P2	5.000	5.03	4.938	4	3.88	1.540	1.540
K	1.000	0.98	1.103	9	5.20	2.622	2.564
Na	1.000	0.98	1.106	7	7.80	2.912	2.912

Notes: qi = formal oxydation number; sof(i) = site occupation factor; d ar(i) = average distance; d med(i) = weighted average distance; CN(i) = coordination number; ECoN(i)= effective coordination number; σcat = dispersion factor on cationic charges measuring the deviation of the computed charges; σcat=[Σ(q − Q)2/N − 1]1/2 = 0.019.

Figure 5

The surrounding of the seven-coordinated Na+ cation in the ‘S’ site in the structure of KNaCuP2O7. Displacement ellipsoids are drawn at 50% probability level. [Symmetry codes: (i) 1 + x, y, z; (ii) 1 − x, 1 − y, −z; (iii)  + x,  − y, − + z].

Database survey

Table 3 ▸ summarizes lattice parameters and the symmetry of related MM’CuP2O7 (M, M’ = monovalent cation) compounds compiled in the ICSD (ICSD, 2017 ▸). It is apparent that the size of the cation(s) defines the structure type.

Table 3

Structural data (Å, °) for the M,M′2CuP2O7 family of compounds

Compound	Space group	a	b	c	β	Z	Reference
Li2CuP2O7	I2/a	14.068 (2)	4.8600 (8)	8.604 (1)	98.97 (1)	4	Spirlet et al. (1993 ▸)
Li2CuP2O7	C2/c	15.3360 (14)	4.8733 (13)	8.6259 (16)	114.795 (10)	4	Gopalakrishna et al. (2008 ▸)
α-Na2CuP2O7	P21/n	8.823 (3)	13.494 (3)	5.108 (2)	92.77 (3)	4	Erragh et al. (1995 ▸)
β-Na2CuP2O7	C2/c	14.715 (1)	5.704 (2)	8.066 (1)	115.14 (1)	4	Etheredge et al. (1995 ▸)
K2CuP2O7	Pbnm	9.509 (4)	14.389 (6)	5.276 (2)		4	ElMaadi et al. (1995 ▸)
K2CuP2O7	P 21 m	8.056 (2)		5.460 (11)		2	Keates et al. (2014 ▸)
α-Rb2CuP2O7	Pmcn	5.183 (1)	10.096 (1)	15.146 (2)		4	Chernyatieva et al. (2008 ▸)
β-Rb2CuP2O7	Cc	7,002 (1)	12.751 (3)	9.773 (2)	110.93 (3)	4	Shvanskaya et al. (2012 ▸)
Cs2CuP2O7	Cc	7.460 (6)	12.973 (10)	9.980 (8)	111.95	4	Mannasova et al. (2016 ▸)
NaCsCuP2O7	Pmn21	5.147 (2)	15.126 (3)	9.717 (5)		4	Chernyatieva et al. (2009 ▸)
Na1.12Ag0.88CuP2O7	C2/c	15.088 (2)	5.641 (1)	8.171 (1)	116.11 (1)	4	Bennazha et al. (2002 ▸)

Synthesis and crystallization

Crystals of KNaCuP2O7 were obtained from a mixture of KH2PO4, NaH2PO4 and CuO in the molar ratio K:Na:Cu:P = 1:1:2:2. The stoichiometric mixture was finely ground and heated in a porcelain crucible at 623 K for 12 h to eliminate volatile products. The temperature was then increased to 873 K and held for 15 d until fusion was reached. The sample was slowly cooled (5 K d−1) to 500 K and finally allowed to cool radiatively to room temperature. The product was washed with water and rinsed with an aqueous solution of HCl (low concentration). Only one type of regular light-blue prismatic crystals was observed. The obtained crystals were ground and checked by powder X-ray diffraction. Rietveld analysis with the program TOPAS 4.2 (Coelho, 2009 ▸) revealed a single-phase product of KNaCuP2O7.

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 4 ▸. The occupancy of the Na+ and K+ sites was checked by independent refinement of the site occupation factors. In each case, full occupancy was observed without the contribution of the other cation. The maximum and minimum electron densities remaining in the difference-Fourier map are located 0.67 Å from O7 and 0.48 Å from Cu, respectively.

Table 4

Experimental details

Crystal data
Chemical formula	KNaCuP2O7
M r	299.57
Crystal system, space group	Monoclinic, P21/n
Temperature (K)	298
a, b, c (Å)	5.176 (3), 13.972 (5), 9.067 (3)
β (°)	91.34 (2)
V (Å3)	655.6 (5)
Z	4
Radiation type	Mo Kα
μ (mm−1)	4.51
Crystal size (mm)	0.18 × 0.13 × 0.09
Data collection
Diffractometer	Enraf–Nonius CAD-4
Absorption correction	ψ scan (North et al., 1968 ▸)
T min, T max	0.868, 0.997
No. of measured, independent and observed [I > 2σ(I)] reflections	3300, 1425, 1291
R int	0.036
(sin θ/λ)max (Å−1)	0.638
Refinement
R[F 2 > 2σ(F 2)], wR(F 2), S	0.020, 0.059, 1.01
No. of reflections	1425
No. of parameters	110
Δρmax, Δρmin (e Å−3)	0.48, −0.42

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▸), XCAD4 (Harms & Wocadlo, 1995 ▸), SHELXS97 (Sheldrick, 2008 ▸), SHELXL2014/7 (Sheldrick, 2015 ▸), DIAMOND (Brandenburg, 2008 ▸) and publCIF (Westrip, 2010 ▸).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S2056989018000130/wm5429sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989018000130/wm5429Isup2.hkl

CCDC reference: 1814470

Additional supporting information: crystallographic information; 3D view; checkCIF report

KNaCuP2O7	F(000) = 580
Mr = 299.57	Dx = 3.035 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 5.176 (3) Å	Cell parameters from 25 reflections
b = 13.972 (5) Å	θ = 10–15°
c = 9.067 (3) Å	µ = 4.51 mm−1
β = 91.34 (2)°	T = 298 K
V = 655.6 (5) Å3	Prism, blue
Z = 4	0.18 × 0.13 × 0.09 mm

Enraf–Nonius CAD-4 diffractometer	Rint = 0.036
Radiation source: fine-focus sealed tube	θmax = 27.0°, θmin = 2.7°
ω/2θ scans	h = −6→6
Absorption correction: ψ scan (North et al., 1968)	k = −2→17
Tmin = 0.868, Tmax = 0.997	l = −11→11
3300 measured reflections	2 standard reflections every 120 min
1425 independent reflections	intensity decay: 1.1%
1291 reflections with I > 2σ(I)

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.020	w = 1/[σ2(Fo2) + (0.0261P)2 + 0.7316P] where P = (Fo2 + 2Fc2)/3
wR(F2) = 0.059	(Δ/σ)max = 0.001
S = 1.01	Δρmax = 0.48 e Å−3
1425 reflections	Δρmin = −0.42 e Å−3
110 parameters	Extinction correction: SHELXL-2014/7 (Sheldrick, 2015), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4
0 restraints	Extinction coefficient: 0.0120 (9)

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.

	x	y	z	Uiso*/Ueq
Cu	0.76039 (5)	0.66590 (2)	0.21888 (3)	0.01093 (12)
P1	0.26527 (12)	0.54589 (5)	0.24314 (7)	0.01115 (15)
P2	0.25245 (11)	0.68972 (4)	0.02910 (6)	0.00898 (15)
Na	0.7521 (2)	0.70912 (8)	−0.16272 (11)	0.0192 (2)
K	0.75717 (11)	0.40697 (4)	0.38439 (6)	0.01850 (15)
O1	0.2223 (4)	0.44115 (15)	0.2502 (2)	0.0223 (4)
O2	0.5278 (3)	0.57557 (14)	0.3077 (2)	0.0176 (4)
O3	0.0576 (3)	0.60643 (15)	0.31633 (19)	0.0179 (4)
O4	0.2588 (3)	0.57729 (12)	0.07029 (18)	0.0126 (4)
O5	0.2938 (3)	0.69884 (14)	−0.13300 (18)	0.0160 (4)
O6	0.4685 (3)	0.73465 (13)	0.12308 (19)	0.0138 (4)
O7	−0.0125 (3)	0.72712 (13)	0.07246 (19)	0.0139 (4)

	U11	U22	U33	U12	U13	U23
Cu	0.00808 (16)	0.01226 (18)	0.01244 (17)	0.00043 (11)	0.00010 (11)	0.00296 (11)
P1	0.0103 (3)	0.0102 (3)	0.0130 (3)	0.0000 (2)	0.0007 (2)	0.0029 (2)
P2	0.0088 (3)	0.0099 (3)	0.0082 (3)	0.0002 (2)	0.0008 (2)	0.0009 (2)
Na	0.0190 (5)	0.0213 (6)	0.0172 (5)	−0.0021 (4)	−0.0001 (4)	0.0020 (5)
K	0.0220 (3)	0.0153 (3)	0.0182 (3)	0.0022 (2)	−0.0008 (2)	0.0000 (2)
O1	0.0272 (10)	0.0115 (10)	0.0280 (10)	−0.0046 (8)	0.0001 (8)	0.0049 (8)
O2	0.0123 (8)	0.0198 (10)	0.0206 (9)	−0.0026 (8)	−0.0022 (7)	0.0093 (8)
O3	0.0151 (9)	0.0261 (10)	0.0126 (8)	0.0075 (8)	0.0008 (7)	0.0036 (8)
O4	0.0178 (8)	0.0093 (8)	0.0107 (8)	−0.0006 (7)	0.0012 (6)	−0.0003 (7)
O5	0.0213 (9)	0.0179 (9)	0.0088 (8)	0.0015 (8)	0.0025 (7)	0.0013 (7)
O6	0.0115 (8)	0.0115 (8)	0.0181 (8)	−0.0002 (7)	−0.0041 (6)	0.0011 (7)
O7	0.0091 (8)	0.0154 (9)	0.0173 (8)	0.0016 (7)	0.0030 (6)	0.0044 (8)

Cu—O2	1.9328 (18)	Na—P2i	3.0977 (12)
Cu—O3i	1.9427 (18)	Na—P2viii	3.1316 (12)
Cu—O6	1.9743 (17)	Na—Cuix	3.2481 (11)
Cu—O7i	1.9872 (17)	Na—Cuviii	3.3550 (11)
Cu—O5ii	2.3225 (19)	K—O2	2.721 (2)
Cu—Naii	3.2481 (11)	K—O5vii	2.7245 (18)
Cu—Naiii	3.3550 (11)	K—O1i	2.764 (2)
Cu—Kiv	3.4966 (7)	K—O6x	2.7969 (19)
Cu—Na	3.5117 (10)	K—O7xi	2.8450 (19)
Cu—K	3.9169 (7)	K—O3v	2.8630 (18)
P1—O1	1.482 (2)	K—O1	3.036 (2)
P1—O2	1.5246 (19)	K—O2v	3.1973 (19)
P1—O3	1.5313 (19)	K—O3i	3.257 (2)
P1—O4	1.6272 (17)	K—P1v	3.4455 (9)
P1—K	3.4260 (9)	K—Cux	3.4965 (7)
P1—Kv	3.4455 (9)	O1—Navii	2.249 (2)
P1—Kvi	3.5329 (9)	O1—Kvi	2.764 (2)
P2—O5	1.4958 (17)	O2—Kv	3.1973 (19)
P2—O6	1.5252 (17)	O3—Cuvi	1.9427 (18)
P2—O7	1.5277 (16)	O3—Naiii	2.772 (2)
P2—O4	1.6148 (18)	O3—Kv	2.8630 (18)
P2—Navi	3.0977 (12)	O3—Kvi	3.257 (2)
P2—Naiii	3.1316 (12)	O5—Cuix	2.3225 (19)
P2—Na	3.1617 (12)	O5—Kvii	2.7245 (18)
Na—O1vii	2.249 (2)	O5—Navi	2.815 (2)
Na—O6viii	2.397 (2)	O6—Naiii	2.397 (2)
Na—O5	2.398 (2)	O6—Kiv	2.7968 (19)
Na—O7i	2.4442 (19)	O7—Cuvi	1.9872 (17)
Na—O3viii	2.772 (2)	O7—Navi	2.4441 (19)
Na—O5i	2.815 (2)	O7—Kxii	2.8451 (19)
Na—O7viii	2.878 (2)	O7—Naiii	2.878 (2)
O2—Cu—O3i	91.46 (8)	O5—Na—Cuix	45.56 (5)
O2—Cu—O6	91.34 (7)	O7i—Na—Cuix	127.14 (6)
O3i—Cu—O6	176.22 (8)	O3viii—Na—Cuix	36.58 (4)
O2—Cu—O7i	160.62 (8)	O5i—Na—Cuix	146.13 (6)
O3i—Cu—O7i	90.77 (7)	O7viii—Na—Cuix	37.24 (4)
O6—Cu—O7i	87.43 (7)	P2i—Na—Cuix	150.57 (4)
O2—Cu—O5ii	109.22 (7)	P2viii—Na—Cuix	58.62 (2)
O3i—Cu—O5ii	92.15 (8)	P2—Na—Cuix	65.37 (2)
O6—Cu—O5ii	84.52 (7)	O1vii—Na—Cuviii	108.65 (6)
O7i—Cu—O5ii	89.93 (7)	O6viii—Na—Cuviii	35.44 (4)
O2—Cu—Naii	134.76 (6)	O5—Na—Cuviii	148.47 (6)
O3i—Cu—Naii	58.24 (7)	O7i—Na—Cuviii	81.19 (5)
O6—Cu—Naii	118.00 (6)	O3viii—Na—Cuviii	77.32 (5)
O7i—Cu—Naii	61.20 (5)	O5i—Na—Cuviii	43.13 (4)
O5ii—Cu—Naii	47.48 (5)	O7viii—Na—Cuviii	86.18 (4)
O2—Cu—Naiii	72.89 (6)	P2i—Na—Cuviii	64.76 (2)
O3i—Cu—Naiii	134.08 (6)	P2viii—Na—Cuviii	57.50 (2)
O6—Cu—Naiii	44.76 (5)	P2—Na—Cuviii	151.44 (4)
O7i—Cu—Naiii	118.06 (6)	Cuix—Na—Cuviii	103.22 (3)
O5ii—Cu—Naiii	55.94 (5)	O2—K—O5vii	102.87 (6)
Naii—Cu—Naiii	103.22 (3)	O2—K—O1i	96.73 (6)
O2—Cu—Kiv	136.72 (6)	O5vii—K—O1i	78.10 (6)
O3i—Cu—Kiv	123.31 (6)	O2—K—O6x	163.30 (6)
O6—Cu—Kiv	53.04 (5)	O5vii—K—O6x	63.38 (5)
O7i—Cu—Kiv	54.45 (5)	O1i—K—O6x	71.95 (6)
O5ii—Cu—Kiv	51.11 (5)	O2—K—O7xi	127.36 (6)
Naii—Cu—Kiv	65.54 (2)	O5vii—K—O7xi	66.49 (5)
Naiii—Cu—Kiv	64.45 (2)	O1i—K—O7xi	127.46 (6)
O2—Cu—Na	121.97 (6)	O6x—K—O7xi	58.05 (5)
O3i—Cu—Na	120.87 (5)	O2—K—O3v	115.68 (6)
O6—Cu—Na	59.42 (5)	O5vii—K—O3v	141.38 (6)
O7i—Cu—Na	42.40 (5)	O1i—K—O3v	98.78 (6)
O5ii—Cu—Na	115.40 (5)	O6x—K—O3v	78.91 (6)
Naii—Cu—Na	102.98 (2)	O7xi—K—O3v	87.26 (6)
Naiii—Cu—Na	103.54 (2)	O2—K—O1	51.17 (5)
Kiv—Cu—Na	64.59 (2)	O5vii—K—O1	71.36 (6)
O2—Cu—K	39.55 (6)	O1i—K—O1	126.29 (7)
O3i—Cu—K	56.02 (6)	O6x—K—O1	125.76 (6)
O6—Cu—K	127.43 (5)	O7xi—K—O1	77.84 (5)
O7i—Cu—K	131.41 (5)	O3v—K—O1	132.24 (6)
O5ii—Cu—K	122.07 (5)	O2—K—O2v	87.12 (5)
Naii—Cu—K	112.35 (2)	O5vii—K—O2v	137.25 (6)
Naiii—Cu—K	110.35 (2)	O1i—K—O2v	142.70 (6)
Kiv—Cu—K	172.759 (11)	O6x—K—O2v	109.37 (5)
Na—Cu—K	122.43 (2)	O7xi—K—O2v	74.42 (5)
O1—P1—O2	112.67 (12)	O3v—K—O2v	47.81 (5)
O1—P1—O3	114.78 (12)	O1—K—O2v	84.43 (5)
O2—P1—O3	108.17 (11)	O2—K—O3i	54.42 (5)
O1—P1—O4	107.95 (11)	O5vii—K—O3i	110.06 (5)
O2—P1—O4	107.13 (10)	O1i—K—O3i	49.03 (5)
O3—P1—O4	105.64 (10)	O6x—K—O3i	119.15 (5)
O1—P1—K	62.31 (8)	O7xi—K—O3i	176.12 (5)
O2—P1—K	50.40 (8)	O3v—K—O3i	94.86 (5)
O3—P1—K	132.38 (7)	O1—K—O3i	102.97 (5)
O4—P1—K	120.75 (7)	O2v—K—O3i	109.40 (5)
O1—P1—Kv	97.92 (9)	O2—K—P1	25.58 (4)
O2—P1—Kv	67.78 (7)	O5vii—K—P1	86.44 (4)
O3—P1—Kv	55.22 (7)	O1i—K—P1	112.63 (5)
O4—P1—Kv	153.15 (7)	O6x—K—P1	148.42 (4)
K—P1—Kv	77.51 (2)	O7xi—K—P1	102.86 (4)
O1—P1—Kvi	47.78 (8)	O3v—K—P1	128.38 (4)
O2—P1—Kvi	132.43 (7)	O1—K—P1	25.61 (4)
O3—P1—Kvi	67.06 (8)	O2v—K—P1	85.94 (4)
O4—P1—Kvi	119.91 (7)	O3i—K—P1	78.37 (3)
K—P1—Kvi	96.10 (2)	O2—K—P1v	93.47 (4)
Kv—P1—Kvi	72.974 (19)	O5vii—K—P1v	156.78 (4)
O5—P2—O6	113.20 (10)	O1i—K—P1v	116.62 (5)
O5—P2—O7	111.96 (10)	O6x—K—P1v	102.54 (4)
O6—P2—O7	111.49 (10)	O7xi—K—P1v	90.50 (4)
O5—P2—O4	107.91 (10)	O3v—K—P1v	26.06 (4)
O6—P2—O4	105.10 (10)	O1—K—P1v	108.15 (4)
O7—P2—O4	106.66 (10)	O2v—K—P1v	26.19 (3)
O5—P2—Navi	65.03 (7)	O3i—K—P1v	92.83 (4)
O6—P2—Navi	150.48 (8)	P1—K—P1v	102.49 (2)
O7—P2—Navi	51.00 (7)	O2—K—Cux	139.21 (4)
O4—P2—Navi	103.13 (7)	O5vii—K—Cux	41.57 (4)
O5—P2—Naiii	147.30 (9)	O1i—K—Cux	93.78 (5)
O6—P2—Naiii	48.05 (7)	O6x—K—Cux	34.34 (3)
O7—P2—Naiii	66.21 (7)	O7xi—K—Cux	34.63 (3)
O4—P2—Naiii	103.48 (7)	O3v—K—Cux	101.36 (5)
Navi—P2—Naiii	116.33 (3)	O1—K—Cux	91.51 (4)
O5—P2—Na	46.71 (7)	O2v—K—Cux	107.32 (4)
O6—P2—Na	70.95 (7)	O3i—K—Cux	141.53 (4)
O7—P2—Na	149.66 (7)	P1—K—Cux	115.54 (2)
O4—P2—Na	101.43 (7)	P1v—K—Cux	116.45 (2)
Navi—P2—Na	111.56 (3)	P1—O1—Navii	153.68 (14)
Naiii—P2—Na	118.02 (3)	P1—O1—Kvi	108.83 (11)
O1vii—Na—O6viii	89.29 (8)	Navii—O1—Kvi	93.05 (7)
O1vii—Na—O5	92.89 (8)	P1—O1—K	92.08 (9)
O6viii—Na—O5	126.37 (7)	Navii—O1—K	86.20 (7)
O1vii—Na—O7i	111.80 (8)	Kvi—O1—K	126.29 (7)
O6viii—Na—O7i	116.12 (7)	P1—O2—Cu	125.16 (11)
O5—Na—O7i	112.48 (7)	P1—O2—K	104.02 (10)
O1vii—Na—O3viii	150.23 (8)	Cu—O2—K	113.55 (8)
O6viii—Na—O3viii	79.37 (6)	P1—O2—Kv	86.03 (8)
O5—Na—O3viii	72.83 (6)	Cu—O2—Kv	128.21 (9)
O7i—Na—O3viii	97.87 (7)	K—O2—Kv	92.88 (5)
O1vii—Na—O5i	85.37 (7)	P1—O3—Cuvi	126.56 (11)
O6viii—Na—O5i	67.10 (6)	P1—O3—Naiii	106.61 (10)
O5—Na—O5i	166.46 (9)	Cuvi—O3—Naiii	85.17 (8)
O7i—Na—O5i	56.39 (5)	P1—O3—Kv	98.72 (8)
O3viii—Na—O5i	114.42 (7)	Cuvi—O3—Kv	134.68 (8)
O1vii—Na—O7viii	91.46 (7)	Naiii—O3—Kv	83.27 (6)
O6viii—Na—O7viii	56.27 (5)	P1—O3—Kvi	87.28 (9)
O5—Na—O7viii	70.10 (6)	Cuvi—O3—Kvi	94.34 (7)
O7i—Na—O7viii	156.06 (5)	Naiii—O3—Kvi	163.09 (7)
O3viii—Na—O7viii	59.34 (5)	Kv—O3—Kvi	85.14 (5)
O5i—Na—O7viii	123.32 (6)	P2—O4—P1	119.01 (11)
O1vii—Na—P2i	93.49 (6)	P2—O5—Cuix	128.83 (11)
O6viii—Na—P2i	94.77 (5)	P2—O5—Na	106.28 (10)
O5—Na—P2i	138.41 (6)	Cuix—O5—Na	86.95 (7)
O7i—Na—P2i	29.06 (4)	P2—O5—Kvii	139.70 (11)
O3viii—Na—P2i	114.67 (5)	Cuix—O5—Kvii	87.32 (5)
O5i—Na—P2i	28.80 (4)	Na—O5—Kvii	90.88 (6)
O7viii—Na—P2i	150.56 (5)	P2—O5—Navi	86.16 (8)
O1vii—Na—P2viii	96.04 (6)	Cuix—O5—Navi	80.94 (6)
O6viii—Na—P2viii	28.24 (4)	Na—O5—Navi	166.46 (9)
O5—Na—P2viii	98.55 (5)	Kvii—O5—Navi	82.58 (6)
O7i—Na—P2viii	136.17 (6)	P2—O6—Cu	126.10 (11)
O3viii—Na—P2viii	61.77 (4)	P2—O6—Naiii	103.71 (9)
O5i—Na—P2viii	94.99 (5)	Cu—O6—Naiii	99.80 (7)
O7viii—Na—P2viii	29.06 (3)	P2—O6—Kiv	134.97 (10)
P2i—Na—P2viii	121.50 (4)	Cu—O6—Kiv	92.63 (6)
O1vii—Na—P2	99.77 (6)	Naiii—O6—Kiv	89.12 (6)
O6viii—Na—P2	151.35 (6)	P2—O7—Cuvi	124.98 (11)
O5—Na—P2	27.01 (4)	P2—O7—Navi	99.93 (9)
O7i—Na—P2	85.78 (5)	Cuvi—O7—Navi	104.36 (7)
O3viii—Na—P2	79.46 (5)	P2—O7—Kxii	137.96 (10)
O5i—Na—P2	140.25 (5)	Cuvi—O7—Kxii	90.92 (6)
O7viii—Na—P2	96.10 (4)	Navi—O7—Kxii	89.80 (6)
P2i—Na—P2	111.56 (3)	P2—O7—Naiii	84.73 (7)
P2viii—Na—P2	123.17 (4)	Cuvi—O7—Naiii	81.55 (6)
O1vii—Na—Cuix	115.94 (6)	Navi—O7—Naiii	167.87 (8)
O6viii—Na—Cuix	86.18 (5)	Kxii—O7—Naiii	79.43 (5)