Fe^II₂(PO₄)(OH), a synthetic analogue of wolfeite

This paper reports the hydro­thermal synthesis and crystal structure refinement of diiron(II) phosphate hydroxide, Fe^II₂(PO₄)(OH), obtained at 1063 K and 2.5 GPa. This phosphate is the synthetic analogue of the mineral wolfeite, and has a crystal structure topologically identical to those of minerals of the triplite-triploidite group. The complex framework contains edge- and corner-sharing FeO₄(OH) and FeO₄(OH)₂ polyhedra, linked via corner-sharing to the PO₄ tetra­hedra (average P-O distances are between 1.537 and 1.544 Å). Four five-coordinated Fe sites are at the centers of distorted trigonal bipyramids (average Fe-O distances are between 2.070 and 2.105 Å), whereas the coordination environments of the remaining Fe sites are distorted octa­hedra (average Fe-O distances are between 2.146 and 2.180 Å). The Fe-O distances are similar to those observed in natural Mg-rich wolfeite, except for two Fe-O bond distances, which are significantly longer in synthetic Fe²⁺₂(PO₄)(OH).

S1. Comment

Wolfeite, (Fe,Mn)²⁺₂(PO₄)(OH), is a rare phosphate mineral which has been reported in granitic pegmatites (Smeds et al., 1998; Roda et al., 2004) and in metamorphosed phosphatic ironstones (Robinson et al., 1992; Stalder & Rozendaal, 2002). Wolfeite belongs to the triplite–triploidite group of minerals (Strunz & Nickel, 2001; Chopin et al., 2003), which also includes the following phosphates: triplite [(Mn,Fe)²⁺₂(PO₄)F; Waldrop, 1969], zwieselite [(Fe,Mn)²⁺₂(PO₄)F; Yakubovich et al., 1978], triploidite [(Mn,Fe)²⁺₂(PO₄)(OH); Waldrop, 1970], wagnerite [(Mg,Fe²⁺)₂(PO₄)F; Coda et al., 1967], staněkite [(Mn,Fe²⁺,Mg)Fe³⁺(PO₄)O; Keller et al., 2006] and joosteite [Mn²⁺(Mn³⁺,Fe³⁺)(PO₄)O; Keller et al., 2007].

The crystal structures of these phosphates are topologically identical, but owing to the periodic ordering of the F atoms along the b axis, several polytypes have been observed for the F-rich compositions, such as, for example, wagnerite-Ma2bc (P2₁/a, b ≈ 13 Å), wagnerite-Ma5bc (Ia, b ≈ 32 Å), wagnerite-Ma7bc (P2₁, b ≈ 45 Å) and wagnerite-Ma9bc (Ia, b ≈ 57 Å) (Chopin et al., 2003; Ren et al., 2003). The crystal structure of wolfeite has been solved on a natural Mg-rich sample with composition (Fe_1.84Mg_0.16)(PO₄)(OH), collected in the Big Fish River area, Yukon Territory, Canada (Kolitsch, 2003). The b unit-cell parameter, 13.169 (3) Å, indicates that this sample corresponds to the polytype Ma2bc, with space group P2₁/a.

During an extensive investigation of the stability of Na—Fe—Mn-bearing phosphates at high pressure, we performed a hydrothermal experiment at 1063 K and 2.5 GPa, starting from the composition NaFe²⁺(PO₄). This experiment produced small brown isometric crystals, associated with a white powder identified as a marićite-type compound, NaFe²⁺(PO₄). An electron-microprobe analysis of the brown crystals (see below), coupled with a single-crystal structure determination, indicated that they correspond to the synthetic analogue of wolfeite, Fe²⁺₂(PO₄)(OH), which was never previously synthesized. The crystal structure of this pure end-member is reported here and compared with the structure of natural Mg-rich wolfeite (Kolitsch, 2003).

The crystal structure of Fe²⁺₂(PO₄)(OH) has been refined in the monoclinic space group P2₁/a, and shows a complex framework based on edge- and corner-sharing FeO₄(OH) and FeO₄(OH)₂ polyhedra, linked via corner-sharing to the PO₄ tetrahedra (Figs. 1 and 2). The four PO₄ tetrahedra show regular topologies, with average P—O distances of 1.541 (P1), 1.537 (P2), 1.542 (P3) and 1.544 (P4) Å. The five-coordinated Fe1, Fe4, Fe6 and Fe8 sites are at the centers of distorted trigonal bipyramids, with average Fe—O distances of 2.102 (Fe1), 2.105 (Fe4), 2.070 (Fe6) and 2.080 Å (Fe8), whereas the coordination environments of the Fe2, Fe3, Fe5 and Fe7 sites are distorted octahedra, with average Fe—O distances of 2.180 (Fe2), 2.178 (Fe3), 2.152 (Fe5) and 2.146 Å (Fe7). These Fe—O distances are similar to those observed in natural Mg-rich wolfeite (Kolitsch, 2003), except the Fe6—O and Fe7—O bond distances, which are significantly longer in synthetic Fe²⁺₂(PO₄)(OH) (Fe6—O = 2.062 and Fe7—O = 2.139 Å in natural Mg-rich wolfeite). This feature can be explained by the smaller effective ionic radius of Mg²⁺ (0.720 Å; Shannon, 1976), which replaces Fe ²⁺ (0.780 Å; Shannon, 1976) on the Fe6 (24% Mg) and Fe7 (19% Mg) crystallographic sites of natural wolfeite (Kolitsch, 2003).

Bond-valence sums were calculated for each ion using the parameters of Brown & Altermatt (1985). The P bond-valence sums range from 4.88 to 4.96 valence units (v.u.), and the O-atom bond valence sums are within the normal acceptable range (1.78–2.01 v.u.). Atoms O17–O20 have bond-valence sums of 1.04–1.20 v.u., thus indicating that they correspond to the four OH groups of the wolfeite structure (Kolitsch, 2003). For the Fe sites, the bond-valence sums are between 1.84 and 2.04 v.u., thus confirming that iron is essentially divalent. The brown colour of the crystals is probably a result of the presence of small amounts of Fe³⁺.

The hydrogen-bonding scheme of Fe²⁺₂(PO₄)(OH) (Table 1) is similar to that observed in natural Mg-rich wolfeite (Kolitsch, 2003), with weak hydrogen bonds showing O···O distances between 2.72 and ca 3.2 Å. Three of the four OH groups are involved in bifurcated or trifurcated hydrogen bonds, whereas the bond donated by the O20—H4 group has a single acceptor (Table 1).

Related literature

For related literature, see: Boyd & England (1960); Brown & Altermatt (1985); Chopin et al. (2003); Coda et al. (1967); Fransolet (1975); Keller et al. (2006, 2007); Kolitsch (2003); Ren et al. (2003); Robinson et al. (1992); Roda et al. (2004); Shannon (1976); Smeds et al. (1998); Stalder & Rozendaal (2002); Strunz & Nickel (2001); Waldrop (1969, 1970); Yakubovich et al. (1978).

S2. Experimental

The title compound was synthesized under hydrothermal conditions. The starting material was prepared by mixing NaH₂PO₄·H₂O, Fe and Fe₂O₃ in proportions 1:1/3:1/3. About 25 mg of the homogenized mixture was sealed into a gold tube with an outer diameter of 2 mm and a length of 15 mm, containing 2 mg of distilled water. The gold capsule was then inserted in a piston-cylinder apparatus of the type described by Boyd & England (1960), using a pressure cell consisting of rock salt and fired pyrophyllite, with a graphite cylinder as resistance furnace. The sample was maintained for 3 d at 1063 K and 2.5 GPa. The synthesized products consisted of a mixture of small brown isometric crystals of wolfeite, associated with a white powder identified as marićite, NaFe²⁺(PO₄). A chemical analysis of the title compound has been performed. The average of ten point analyses gives P₂O₅ 31.32, FeO 64.52, H₂O 3.97 (calculated value), total 99.81 wt%. The chemical composition, calculated on the basis of one P atom, corresponds to Fe²⁺₂O₄(PO₄)(OH).

S3. Refinement

All non-H atoms were refined anisotropically in the monoclinic P2₁/a space group. In early refinement cycles, H atoms were refined freely and isotropically, but atom H3 was localized at only 0.54 Å from O19. The O—H distances were then restrained to 0.82 (5) Å with the DFIX instruction of SHELXL97 (Sheldrick, 1997). The relatively large isotropic displacement parameter of atom H1 probably corresponds to an artefact. In the final refinement cycle, atomic coordinates identical to those used by Kolitsch (2003) were used.

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2002); cell refinement: CrysAlis RED (Oxford Diffraction, 2002); data reduction: CrysAlis RED (Oxford Diffraction, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ATOMS for Windows (Dowty, 1993); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. A polyhedral representation of the crystal structure of Fe^2+2(PO4)(OH), projected along [010] (perspective view). The P tetrahedra are dark grey, the FeO4(OH)2 octahedra are light grey, and the FeO4(OH) trigonal bipyramids are white. The small grey circles represent H atoms.
	Fig. 2. The crystal structure of Fe^2+2(PO4)(OH), projected along [001] (perspective view). For key see Fig. 1.

diiron(II) phosphate hydroxide

Crystal data

Fe2(PO4)(OH)	F(000) = 1728
Mr = 223.67	Dx = 3.978 Mg m^−3
Monoclinic, P21/a	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yab	Cell parameters from 7779 reflections
a = 12.265 (1) Å	θ = 3.1–39.6°
b = 13.197 (1) Å	µ = 8.09 mm^−1
c = 9.7385 (9) Å	T = 293 K
β = 108.63 (1)°	Small isometric crystal, brown
V = 1493.8 (2) Å^3	0.09 × 0.07 × 0.05 mm
Z = 16

Data collection

Xcalibur with Sapphire2 CCD-area detector diffractometer	8936 independent reflections
Radiation source: fine-focus sealed tube	4515 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
phi and ω scans	θmax = 39.6°, θmin = 2.8°
Absorption correction: numerical after shape optimization (CrysAlis RED; Oxford Diffraction, 2002)	h = −21→22
Tmin = 0.399, Tmax = 0.476	k = −23→23
23682 measured reflections	l = −17→15

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)] = 0.030	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.065	All H-atom parameters refined
S = 0.86	w = 1/[σ^2(Fo^2) + (0.0211P)^2] where P = (Fo^2 + 2Fc^2)/3
8936 reflections	(Δ/σ)max = 0.001
305 parameters	Δρmax = 0.86 e Å^−3
0 restraints	Δρmin = −0.74 e Å^−3

Special details

Experimental. A chemical analysis of the title compound has been performed with a CAMEBAX SX-50 electron microprobe (15 kV acceleration voltage, 20?nA beam current, analyst H.-J. Bernhardt, Ruhr-Universität Bochum, Germany). The standard used was graftonite from Kabira [sample KF16, Fransolet (1975). Unpublished PhD thesis, University of Liège, Belgium] (P, Fe). The average of 10 point analyses gives P2O5 31.32, FeO 64.52, H2O 3.97*, total 99.81 wt. % (*calculated value). The chemical composition, calculated on the basis of 1 P, corresponds to Fe2 + 2.04(PO4)(OH).

654 data frames and 14 reference frames were collected with a framewidth of 0.50 and an exposure time of 20 s resulting in a coverage of 92.5% at a resolution of 0.80 Å and an average redundancy of 8.2. The sample-to-detector distance was 44.35 mm.

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.

Refinement. The reported coordinates were chosen to match those of Kolitsch (2003), in order to facilitate comparisons with the previous literature. This has resulted in the asymmetric unit having P1, P2 and P3 only being directly bonded to three oxygen atoms in each case and P4 only being directly bonded to two oxygen atoms.

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 > σ(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
Fe1	0.18617 (3)	0.47901 (3)	0.19376 (4)	0.01071 (8)
Fe2	0.19694 (3)	0.99592 (3)	0.21291 (4)	0.01149 (8)
Fe3	0.30513 (3)	0.75256 (3)	0.29273 (4)	0.01123 (8)
Fe4	0.31951 (3)	0.26973 (3)	0.30345 (4)	0.01105 (8)
Fe5	0.09624 (3)	0.07077 (3)	0.46901 (4)	0.00972 (8)
Fe6	0.08583 (3)	0.57379 (3)	0.45225 (4)	0.01027 (8)
Fe7	0.39418 (3)	0.67471 (3)	0.03055 (4)	0.00993 (8)
Fe8	0.42078 (3)	0.17817 (3)	0.03819 (4)	0.00997 (8)
P1	0.07905 (5)	0.82099 (5)	0.38026 (7)	0.00676 (12)
P2	0.07602 (5)	0.32635 (5)	0.38299 (7)	0.00686 (12)
P3	0.42315 (5)	0.42210 (5)	0.11279 (7)	0.00687 (12)
P4	0.42299 (5)	0.92823 (5)	0.11949 (7)	0.00710 (12)
O1	0.04820 (15)	0.41441 (13)	0.4692 (2)	0.0119 (4)
O2	0.06179 (15)	0.90778 (13)	0.4786 (2)	0.0106 (3)
O3	0.43109 (15)	0.84131 (13)	0.01601 (19)	0.0109 (3)
O4	0.45629 (15)	0.33759 (13)	0.02469 (19)	0.0106 (3)
O5	0.02660 (15)	0.04732 (14)	0.24280 (19)	0.0124 (4)
O6	0.04222 (15)	0.55422 (14)	0.2321 (2)	0.0128 (4)
O7	0.46693 (15)	0.70339 (13)	0.25990 (19)	0.0105 (4)
O8	0.46736 (15)	0.20329 (13)	0.25925 (19)	0.0117 (4)
O9	0.17370 (15)	0.84765 (13)	0.31467 (19)	0.0105 (3)
O10	0.17260 (15)	0.36039 (13)	0.3235 (2)	0.0114 (4)
O11	0.32383 (14)	0.38410 (13)	0.16570 (19)	0.0106 (4)
O12	0.33438 (15)	0.90383 (13)	0.19549 (19)	0.0104 (3)
O13	0.11945 (15)	0.72824 (13)	0.48136 (19)	0.0100 (4)
O14	0.11844 (15)	0.23468 (13)	0.48289 (19)	0.0099 (4)
O15	0.38401 (15)	0.02293 (13)	0.02153 (19)	0.0111 (4)
O16	0.37744 (15)	0.51319 (13)	0.01106 (19)	0.0105 (4)
O17	0.25267 (15)	0.03010 (14)	0.4355 (2)	0.0127 (3)
O18	0.20709 (16)	0.16164 (13)	0.1946 (2)	0.0138 (4)
O19	0.24270 (15)	0.71909 (14)	0.0681 (2)	0.0115 (3)
O20	0.30206 (15)	0.58279 (13)	0.3086 (2)	0.0136 (4)
H1	0.264 (4)	−0.026 (3)	0.453 (5)	0.081 (16)*
H2	0.152 (3)	0.169 (2)	0.215 (3)	0.031 (10)*
H3	0.234 (3)	0.769 (2)	0.055 (4)	0.054 (14)*
H4	0.361 (2)	0.573 (2)	0.279 (3)	0.022 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Fe1	0.01085 (16)	0.01028 (16)	0.0115 (2)	0.00162 (13)	0.00421 (14)	0.00201 (14)
Fe2	0.01351 (17)	0.01112 (17)	0.0101 (2)	0.00264 (13)	0.00419 (15)	−0.00019 (14)
Fe3	0.01163 (16)	0.01179 (17)	0.0103 (2)	0.00277 (13)	0.00360 (15)	−0.00060 (14)
Fe4	0.01120 (16)	0.01042 (17)	0.0117 (2)	0.00139 (13)	0.00393 (15)	0.00247 (14)
Fe5	0.01012 (15)	0.00916 (17)	0.0101 (2)	0.00001 (12)	0.00349 (14)	−0.00089 (14)
Fe6	0.01072 (16)	0.00859 (16)	0.0119 (2)	−0.00026 (12)	0.00411 (14)	−0.00101 (14)
Fe7	0.01016 (15)	0.00952 (16)	0.01050 (19)	0.00028 (13)	0.00384 (14)	−0.00084 (14)
Fe8	0.00924 (15)	0.00860 (16)	0.0117 (2)	0.00014 (13)	0.00278 (14)	−0.00057 (14)
P1	0.0066 (2)	0.0063 (3)	0.0075 (3)	−0.0002 (2)	0.0024 (2)	0.0003 (2)
P2	0.0074 (2)	0.0061 (3)	0.0076 (3)	−0.0002 (2)	0.0031 (2)	0.0002 (2)
P3	0.0068 (2)	0.0061 (3)	0.0080 (3)	0.0003 (2)	0.0027 (2)	0.0003 (2)
P4	0.0071 (2)	0.0065 (3)	0.0081 (3)	−0.0004 (2)	0.0031 (2)	−0.0001 (2)
O1	0.0148 (8)	0.0079 (8)	0.0156 (10)	−0.0011 (7)	0.0087 (7)	−0.0026 (7)
O2	0.0135 (8)	0.0078 (8)	0.0126 (9)	−0.0012 (6)	0.0072 (7)	−0.0030 (7)
O3	0.0123 (8)	0.0096 (8)	0.0116 (9)	−0.0009 (6)	0.0050 (7)	−0.0020 (7)
O4	0.0128 (8)	0.0075 (8)	0.0137 (9)	−0.0009 (6)	0.0070 (7)	−0.0018 (7)
O5	0.0098 (8)	0.0164 (10)	0.0098 (10)	0.0012 (7)	0.0013 (7)	0.0007 (7)
O6	0.0088 (8)	0.0158 (9)	0.0128 (10)	0.0031 (7)	0.0020 (7)	0.0003 (7)
O7	0.0097 (7)	0.0125 (9)	0.0086 (9)	0.0017 (6)	0.0019 (7)	0.0006 (7)
O8	0.0130 (8)	0.0131 (9)	0.0075 (9)	0.0031 (7)	0.0013 (7)	−0.0002 (7)
O9	0.0107 (7)	0.0086 (8)	0.0143 (9)	0.0019 (6)	0.0068 (7)	0.0017 (7)
O10	0.0113 (8)	0.0100 (8)	0.0152 (10)	0.0023 (6)	0.0075 (7)	0.0026 (7)
O11	0.0101 (8)	0.0102 (8)	0.0139 (10)	0.0004 (6)	0.0071 (7)	0.0026 (7)
O12	0.0108 (7)	0.0106 (8)	0.0124 (9)	0.0001 (6)	0.0075 (7)	0.0006 (7)
O13	0.0124 (8)	0.0067 (8)	0.0101 (9)	−0.0015 (6)	0.0026 (7)	0.0015 (7)
O14	0.0110 (8)	0.0080 (8)	0.0100 (9)	−0.0002 (6)	0.0023 (7)	0.0026 (7)
O15	0.0131 (8)	0.0076 (8)	0.0123 (10)	0.0004 (7)	0.0037 (7)	0.0012 (7)
O16	0.0113 (8)	0.0083 (8)	0.0115 (9)	0.0000 (6)	0.0031 (7)	0.0016 (7)
O17	0.0122 (8)	0.0097 (8)	0.0151 (10)	−0.0010 (7)	0.0030 (7)	−0.0007 (7)
O18	0.0158 (9)	0.0117 (8)	0.0153 (10)	−0.0029 (7)	0.0069 (8)	−0.0023 (7)
O19	0.0109 (8)	0.0092 (8)	0.0136 (10)	0.0004 (6)	0.0025 (7)	0.0015 (7)
O20	0.0131 (8)	0.0134 (8)	0.0157 (10)	−0.0025 (7)	0.0067 (8)	−0.0016 (7)

Geometric parameters (Å, º)

Fe1—O20	2.0326 (18)	Fe6—O6	2.0539 (19)
Fe1—O10	2.0517 (18)	Fe6—O13	2.0811 (18)
Fe1—O15^i	2.0785 (18)	Fe6—O1	2.1710 (18)
Fe1—O6	2.1592 (17)	Fe7—O4^vii	2.0760 (17)
Fe1—O11	2.1883 (17)	Fe7—O19	2.0886 (18)
Fe2—O16^i	2.0906 (18)	Fe7—O16	2.1441 (18)
Fe2—O17^ii	2.1030 (19)	Fe7—O18^i	2.1545 (19)
Fe2—O12	2.1284 (17)	Fe7—O7	2.1575 (18)
Fe2—O18^ii	2.2010 (18)	Fe7—O3	2.2584 (18)
Fe2—O9	2.2522 (18)	Fe8—O19^viii	2.0144 (18)
Fe2—O5^ii	2.3018 (18)	Fe8—O3^vii	2.0634 (18)
Fe3—O14^iii	2.0978 (18)	Fe8—O8	2.0701 (18)
Fe3—O9	2.1069 (17)	Fe8—O15	2.0929 (18)
Fe3—O19	2.1206 (19)	Fe8—O4	2.1610 (18)
Fe3—O7	2.2061 (17)	P1—O7^ix	1.5294 (18)
Fe3—O20	2.2469 (17)	P1—O9	1.5340 (18)
Fe3—O12	2.2865 (18)	P1—O13	1.5497 (18)
Fe4—O18	2.0312 (18)	P1—O2	1.5503 (18)
Fe4—O11	2.0313 (18)	P2—O8^x	1.5348 (19)
Fe4—O13^iv	2.0615 (18)	P2—O1	1.5348 (19)
Fe4—O8	2.1774 (18)	P2—O14	1.5354 (18)
Fe4—O10	2.2230 (18)	P2—O10	1.5423 (18)
Fe5—O17	2.1156 (18)	P3—O5^xi	1.5329 (19)
Fe5—O5	2.1158 (18)	P3—O4	1.5388 (18)
Fe5—O20^iv	2.1322 (19)	P3—O16	1.5448 (19)
Fe5—O2^v	2.1746 (17)	P3—O11	1.5498 (17)
Fe5—O14	2.1790 (18)	P4—O12	1.5318 (17)
Fe5—O2^vi	2.1998 (18)	P4—O6^xii	1.5395 (18)
Fe6—O17^iii	2.0170 (18)	P4—O3	1.5509 (19)
Fe6—O1^v	2.0283 (18)	P4—O15^ii	1.5521 (19)
O20—Fe1—O10	110.81 (8)	O20^iv—Fe5—O2^vi	95.03 (7)
O20—Fe1—O15^i	111.02 (7)	O2^v—Fe5—O2^vi	85.39 (7)
O10—Fe1—O15^i	138.17 (7)	O14—Fe5—O2^vi	171.86 (7)
O20—Fe1—O6	93.55 (7)	O17^iii—Fe6—O1^v	126.26 (8)
O10—Fe1—O6	90.73 (7)	O17^iii—Fe6—O6	114.40 (7)
O15^i—Fe1—O6	87.02 (7)	O1^v—Fe6—O6	115.53 (7)
O20—Fe1—O11	91.29 (7)	O17^iii—Fe6—O13	95.08 (7)
O10—Fe1—O11	81.82 (7)	O1^v—Fe6—O13	91.30 (7)
O15^i—Fe1—O11	96.96 (7)	O6—Fe6—O13	103.86 (7)
O6—Fe1—O11	172.19 (7)	O17^iii—Fe6—O1	82.97 (7)
O16^i—Fe2—O17^ii	160.36 (7)	O1^v—Fe6—O1	80.10 (7)
O16^i—Fe2—O12	94.13 (7)	O6—Fe6—O1	88.11 (7)
O17^ii—Fe2—O12	101.52 (7)	O13—Fe6—O1	167.50 (7)
O16^i—Fe2—O18^ii	79.89 (7)	O4^vii—Fe7—O19	167.46 (7)
O17^ii—Fe2—O18^ii	82.07 (7)	O4^vii—Fe7—O16	88.10 (7)
O12—Fe2—O18^ii	119.62 (7)	O19—Fe7—O16	103.23 (7)
O16^i—Fe2—O9	118.65 (7)	O4^vii—Fe7—O18^i	89.99 (7)
O17^ii—Fe2—O9	77.17 (7)	O19—Fe7—O18^i	86.83 (7)
O12—Fe2—O9	75.74 (6)	O16—Fe7—O18^i	79.78 (7)
O18^ii—Fe2—O9	156.52 (7)	O4^vii—Fe7—O7	100.05 (7)
O16^i—Fe2—O5^ii	89.34 (7)	O19—Fe7—O7	82.33 (7)
O17^ii—Fe2—O5^ii	79.38 (7)	O16—Fe7—O7	105.21 (7)
O12—Fe2—O5^ii	162.23 (7)	O18^i—Fe7—O7	168.85 (7)
O18^ii—Fe2—O5^ii	78.14 (7)	O4^vii—Fe7—O3	81.28 (7)
O9—Fe2—O5^ii	87.30 (6)	O19—Fe7—O3	86.87 (7)
O14^iii—Fe3—O9	93.62 (7)	O16—Fe7—O3	167.90 (7)
O14^iii—Fe3—O19	160.93 (7)	O18^i—Fe7—O3	94.36 (7)
O9—Fe3—O19	101.12 (7)	O7—Fe7—O3	82.48 (7)
O14^iii—Fe3—O7	89.68 (7)	O19^viii—Fe8—O3^vii	135.66 (8)
O9—Fe3—O7	160.50 (7)	O19^viii—Fe8—O8	112.97 (7)
O19—Fe3—O7	80.47 (7)	O3^vii—Fe8—O8	108.23 (7)
O14^iii—Fe3—O20	80.09 (7)	O19^viii—Fe8—O15	93.90 (7)
O9—Fe3—O20	123.84 (7)	O3^vii—Fe8—O15	92.51 (7)
O19—Fe3—O20	81.65 (7)	O8—Fe8—O15	102.62 (7)
O7—Fe3—O20	75.66 (6)	O19^viii—Fe8—O4	83.95 (7)
O14^iii—Fe3—O12	116.91 (7)	O3^vii—Fe8—O4	83.96 (7)
O9—Fe3—O12	75.42 (6)	O8—Fe8—O4	85.03 (7)
O19—Fe3—O12	78.89 (7)	O15—Fe8—O4	172.28 (7)
O7—Fe3—O12	85.95 (6)	O7^ix—P1—O9	110.12 (10)
O20—Fe3—O12	155.14 (7)	O7^ix—P1—O13	110.34 (10)
O18—Fe4—O11	109.50 (8)	O9—P1—O13	108.35 (10)
O18—Fe4—O13^iv	108.03 (7)	O7^ix—P1—O2	111.23 (10)
O11—Fe4—O13^iv	142.29 (7)	O9—P1—O2	111.01 (10)
O18—Fe4—O8	94.79 (7)	O13—P1—O2	105.67 (10)
O11—Fe4—O8	88.26 (7)	O8^x—P2—O1	109.49 (10)
O13^iv—Fe4—O8	92.24 (7)	O8^x—P2—O14	109.28 (11)
O18—Fe4—O10	89.40 (7)	O1—P2—O14	109.84 (10)
O11—Fe4—O10	81.42 (7)	O8^x—P2—O10	110.97 (10)
O13^iv—Fe4—O10	95.45 (7)	O1—P2—O10	108.46 (10)
O8—Fe4—O10	169.66 (7)	O14—P2—O10	108.78 (10)
O17—Fe5—O5	83.49 (7)	O5^xi—P3—O4	110.79 (10)
O17—Fe5—O20^iv	84.86 (7)	O5^xi—P3—O16	111.10 (11)
O5—Fe5—O20^iv	168.29 (7)	O4—P3—O16	108.23 (10)
O17—Fe5—O2^v	171.66 (7)	O5^xi—P3—O11	109.98 (10)
O5—Fe5—O2^v	99.77 (7)	O4—P3—O11	109.06 (10)
O20^iv—Fe5—O2^v	91.61 (7)	O16—P3—O11	107.59 (10)
O17—Fe5—O14	99.20 (7)	O12—P4—O6^xii	110.29 (10)
O5—Fe5—O14	102.16 (7)	O12—P4—O3	111.16 (10)
O20^iv—Fe5—O14	80.92 (7)	O6^xii—P4—O3	109.30 (10)
O2^v—Fe5—O14	87.67 (7)	O12—P4—O15^ii	109.84 (10)
O17—Fe5—O2^vi	87.39 (7)	O6^xii—P4—O15^ii	110.65 (11)
O5—Fe5—O2^vi	83.22 (7)	O3—P4—O15^ii	105.50 (10)

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

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O17—H1···O9^vi	0.77 (3)	2.20 (4)	2.719 (3)	126 (4)
O17—H1···O1^iv	0.77 (3)	2.32 (4)	2.777 (3)	119 (4)
O17—H1···O10^iv	0.77 (3)	2.55 (4)	3.161 (3)	138 (4)
O18—H2···O5	0.77 (3)	2.30 (3)	2.839 (2)	128 (3)
O18—H2···O4^x	0.77 (3)	2.52 (3)	2.992 (3)	121 (3)
O19—H3···O12	0.67 (3)	2.34 (4)	2.803 (3)	127 (4)
O19—H3···O4^i	0.67 (3)	2.39 (4)	2.795 (2)	121 (4)
O19—H3···O11^i	0.67 (3)	2.54 (4)	3.067 (3)	137 (4)
O20—H4···O7	0.87 (3)	2.19 (3)	2.731 (2)	120 (2)

Symmetry codes: (i) −x+1/2, y+1/2, −z; (iv) −x+1/2, y−1/2, −z+1; (vi) x, y−1, z; (x) x−1/2, −y+1/2, z.