The iron phosphate NaBaFe2(PO4)3

Hidouri, M.; Jerbi, H.; Ben Amara, M.

doi:10.1107/S1600536808023040

inorganic compounds

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ISSN: 2056-9890

Volume 64| Part 8| August 2008| Page i51

doi:10.1107/S1600536808023040

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The iron phosphate NaBaFe₂(PO₄)₃

Mourad Hidouri,^a ^* Hasna Jerbi ^a and Mongi Ben Amara ^a

^aFaculté des Sciences de Monastir, 5019 Monastir, Tunisia
^*Correspondence e-mail: mourad_hidouri@yahoo.fr

(Received 27 May 2008; accepted 22 July 2008; online 31 July 2008)

A new iron phosphate, sodium barium diiron tris(phosphate), NaBaFe₂(PO₄)₃, has been synthesized by the flux method and shown to exhibit the well known langbeinite type structure. The Na, Ba and Fe atoms all lie on threefold axes, while the P and O atoms occupy general positions, one of the O atoms being disordered over two positions, with site occupancy factors of ca 0.7 and 0.3. The [Fe₂(PO₄)₃]_∞ framework consists of FeO₆ octahedra sharing all their corners with the PO₄ tetrahedra. The Na⁺ and Ba²⁺ cations are almost equally distributed over two distinct cavities, in which they occupy slightly different positions.

Related literature

For related literature, see: Baur (1974 ); Moffat (1978 ); Padhi et al. (1997 ); Shannon (1976 ). For the structure of langbeinite, see Zemann & Zemann (1957 ); Battle et al. (1986 , 1988 ).

Experimental

Crystal data

NaBaFe₂(PO₄)₃
M_r = 556.94
Cubic, P 2₁ 3
a = 9.796 (1) Å
V = 940.1 (3) Å³
Z = 4
Mo Kα radiation
μ = 7.82 mm⁻¹
T = 293 (2) K
0.1 × 0.1 × 0.1 mm

Data collection

Enraf–Nonius CAD4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.35, T_max = 0.46
2114 measured reflections
657 independent reflections
644 reflections with I > 2σ(I)
R_int = 0.082
2 standard reflections frequency: 120 min intensity decay: 1%

Refinement

R[F² > 2σ(F²)] = 0.025
wR(F²) = 0.059
S = 0.92
657 reflections
70 parameters
4 restraints
Δρ_max = 0.57 e Å⁻³
Δρ_min = −0.49 e Å⁻³
Absolute structure: Flack (1983 ), 123 Friedel pairs
Flack parameter: −0.03 (3)

Table 1
Selected bond angles (°)

O4Bⁱ—Fe2—O1ⁱⁱ	89.8 (8)
O3—P—O4A	115.1 (3)
Symmetry codes: (i) z, x, y; (ii) $[-z+{\script{3\over 2}}, -x+1, y-{\script{1\over 2}}]$ .

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1998 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808023040/br2076sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808023040/br2076Isup2.hkl

checkCIF report

Comment top

Iron phosphates are of increasing interst because of their potential applications in various fields ranging from catalysis (Moffat, 1978) to ionic conductivity (Padhi et al., 1997). Moreover, these materials are very attractive in terms of basic reasearch because they exhibit a rich structural chemistry owing to the possible (+2/+3) mixed valence of iron and its tendency to exhibit various coordination polyhedra.

The title cmpound, sodium barium diiron phosphate NaBaFe₂(PO₄)₃ was isolated during a systematic investigation of the Na₂O–MO–Fe₂O₃–P₂O₅ systems where M is a divalent cation. Its structure (Fig. 1) exhibits a three-dimensional [Fe₂(PO₄)₃]_∞ framework built up from corner-sharing FeO₆ octahedra and PO₄ tetrahedra. Each octahedron is linked to six adjacent tetrahedra and reciprocally each tetrahedron is connected to four neighboring octahedra. This framework delimits two sorts of large cavities, statistically occupied by the Na⁺ and Ba²⁺ cations.

The two symmetry distinct FeO₆ octahedra contained in this structure are somewhat distorted as indicated by the Fe—O distances ranging from 1.963 (5) to 1.991 (4) Å. The average <Fe—O> distances of 1.986 Å for Fe(1) and 1.973 Å for Fe(2) are slightly lower than the value 2.03 Å predicted by Shannon for octahedral Fe³⁺ ions (Shannon, 1976).

The PO₄ tetrahedron is strongly distorted with P—O distances scattering from 1.47 (2) to 1.547 (7) Å. Corresponding average value of 1.511 Å agrees with those frequently observed in anhydrous monophosphates (Baur, 1974).

The Na⁺ and Ba²⁺ cations are statistically distributed over two distinct cavities in which they occupy slightly different positions and have partial occupancies of 0.47, 0.53, 0.53 and 0.47 for Na(1), Ba(1), Na(2) and Ba(2), respectively. The environments of these cations (Fig. 2) were determined assuming all cation-oxygen distances are shorter than the shortest to next cationic site. Each of the Na(1), Ba(1) and Ba(2) environments consists of nine O atoms with cation-oxygen distances in the ranges 2.76 (2)–3.04 (2) Å, 2.753 (7)–2.950 (6) Å and 2.722 (5)–3.047 (7) Å for Na(1), Ba(1) and Ba(2), respectively. The Na(2) environment consists of six O atoms with Na—O distances varying from 2.604 (8) and 3.004 (6) Å.

The as-described structure is closely related to the langbeinite-like phosphates KBaM₂(PO₄)₃ (M = Fe, Cr) (Battle et al., 1986, 1988). However, it differs by the fact that the atom O4, which occupies a single site in the potassium phosphates, is, in the title compound, statistically occupying two distinct positions, O4A and O4B which exhibit partial occupancies of 0.7 and 0.3, respectively. These different values can be explained by the fact that the O4A site is occupied if it is bonded to Na(1), Ba(1) or Ba(2) whereas the O4B site is occupied if it is bonded to Na(1) or Ba(1).

Related literature top

For related literature, see: Baur (1974); Moffat (1978); Padhi et al. (1997); Shannon (1976). For the structure of langbeinite, see Zemann & Zemann (1957); Battle et al. (1986, 1988).

Experimental top

Single crystals of the title compund were grown in a flux of sodium dimolybdate Na₂Mo₂O₇ with an atomic ratio P:Mo = 6:1. A starting mixture of 1.071 g of Na₂CO₃, 1.993 g of BaCO₃, 8.162 g of Fe(NO₃)₃.9H₂O, 4.002 g of (NH₄)₂HPO₄ and 1.454 g of MoO₃ was dissolved in nitric acid and the obtained solution was evaporated to dryness. The dry residue was transferred into a platinum crucible and then heated up 600°C to decompose H₂O and NH₃. In a second step, the sample was melted for 1 h at 900°C and then cooled down to room temperature with a 10° h^-1 rate. The final product, obtained after washing with warm water to dissolve the flux is essentially composed of pink and prismatic shaped crystals. Their qualitative elemental analysis using electron microprobe analysis indicated the presence of Na, Ba, Fe and P and no impurity elements have been detected.

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. A projection of the structure along the [111] direction.
	Fig. 2. The environments of the Na and Ba sites showing the anisotropic atomic displacements at the 50% level.

sodium barium diiron tris(phosphate) top

Crystal data top

NaBaFe₂(PO₄)₃	D_x = 3.935 Mg m⁻³
M_r = 556.94	Mo Kα radiation, λ = 0.71073 Å
Cubic, P2₁3	Cell parameters from 25 reflections
Hall symbol: P 2ac 2ab 3	θ = 9.0–13.0°
a = 9.796 (1) Å	µ = 7.82 mm⁻¹
V = 940.1 (3) Å³	T = 293 K
Z = 4	Prism, pink
F(000) = 1040	0.1 × 0.1 × 0.1 mm

Data collection top

Enraf–Nonius CAD-4 diffractometer	644 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.082
Graphite monochromator	θ_max = 29.9°, θ_min = 2.9°
ω/2θ scans	h = −1→13
Absorption correction: ψ scan (North et al., 1968)	k = −1→13
T_min = 0.35, T_max = 0.46	l = −1→13
2114 measured reflections	2 standard reflections every 120 min
657 independent reflections	intensity decay: 1%

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	w = 1/[σ²(F_o²) + 5.7579P] where P = (F_o² + 2F_c²)/3
R[F² > 2σ(F²)] = 0.025	(Δ/σ)_max = 0.002
wR(F²) = 0.059	Δρ_max = 0.57 e Å⁻³
S = 0.92	Δρ_min = −0.49 e Å⁻³
657 reflections	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
70 parameters	Extinction coefficient: 0.0145 (15)
4 restraints	Absolute structure: Flack (1983), with how many Friedel pairs?
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: −0.03 (3)

Crystal data top

NaBaFe₂(PO₄)₃	Z = 4
M_r = 556.94	Mo Kα radiation
Cubic, P2₁3	µ = 7.82 mm⁻¹
a = 9.796 (1) Å	T = 293 K
V = 940.1 (3) Å³	0.1 × 0.1 × 0.1 mm

Data collection top

Enraf–Nonius CAD-4 diffractometer	644 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.082
T_min = 0.35, T_max = 0.46	2 standard reflections every 120 min
2114 measured reflections	intensity decay: 1%
657 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.025	4 restraints
wR(F²) = 0.059	Δρ_max = 0.57 e Å⁻³
S = 0.92	Δρ_min = −0.49 e Å⁻³
657 reflections	Absolute structure: Flack (1983), with how many Friedel pairs?
70 parameters	Absolute structure parameter: −0.03 (3)

Special details top

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

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Na1	0.9427 (12)	0.9427 (12)	0.9427 (12)	0.0144 (3)	0.4738 (16)
Ba1	0.92953 (9)	0.92953 (9)	0.92953 (9)	0.0144 (3)	0.5262 (16)
Na2	0.6862 (8)	0.6862 (8)	0.6862 (8)	0.0232 (4)	0.5262 (16)
Ba2	0.70555 (8)	0.70555 (8)	0.70555 (8)	0.0232 (4)	0.4738 (16)
Fe1	0.35313 (6)	0.85313 (6)	0.64687 (6)	0.0104 (2)
Fe2	0.91362 (6)	0.08638 (6)	0.58638 (6)	0.0101 (2)
P	0.03742 (10)	0.77099 (11)	0.62578 (10)	0.0068 (2)
O1	0.9926 (5)	0.9134 (4)	0.6562 (7)	0.0461 (14)
O2	0.9463 (5)	0.6999 (6)	0.5243 (5)	0.0440 (13)
O3	0.1846 (4)	0.7653 (6)	0.5752 (5)	0.0368 (12)
O4A	0.0112 (7)	0.6985 (10)	0.7629 (8)	0.0389 (18)	0.701 (4)
O4B	0.0527 (17)	0.672 (2)	0.738 (2)	0.0389 (18)	0.299 (4)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Na1	0.0144 (3)	0.0144 (3)	0.0144 (3)	−0.0019 (3)	−0.0019 (3)	−0.0019 (3)
Ba1	0.0144 (3)	0.0144 (3)	0.0144 (3)	−0.0019 (3)	−0.0019 (3)	−0.0019 (3)
Na2	0.0232 (4)	0.0232 (4)	0.0232 (4)	0.0016 (3)	0.0016 (3)	0.0016 (3)
Ba2	0.0232 (4)	0.0232 (4)	0.0232 (4)	0.0016 (3)	0.0016 (3)	0.0016 (3)
Fe1	0.0104 (2)	0.0104 (2)	0.0104 (2)	0.0001 (2)	−0.0001 (2)	−0.0001 (2)
Fe2	0.0101 (2)	0.0101 (2)	0.0101 (2)	0.0024 (2)	0.0024 (2)	−0.0024 (2)
P	0.0066 (4)	0.0073 (4)	0.0064 (4)	−0.0005 (3)	−0.0028 (3)	0.0010 (3)
O1	0.045 (3)	0.0170 (19)	0.076 (4)	0.0191 (19)	−0.015 (3)	−0.015 (2)
O2	0.029 (2)	0.061 (3)	0.042 (3)	0.003 (2)	−0.025 (2)	−0.031 (2)
O3	0.0120 (16)	0.063 (3)	0.035 (2)	−0.0091 (18)	0.0085 (16)	−0.023 (2)
O4A	0.020 (4)	0.066 (5)	0.031 (3)	0.020 (3)	0.015 (3)	0.040 (3)
O4B	0.020 (4)	0.066 (5)	0.031 (3)	0.020 (3)	0.015 (3)	0.040 (3)

Geometric parameters (Å, º) top

Na1—O1ⁱ	2.864 (12)	Ba2—O3^xiii	2.772 (5)
Na1—O1	2.864 (12)	Ba2—O3^xiv	2.772 (5)
Na1—O1ⁱⁱ	2.864 (12)	Ba2—O2ⁱⁱ	2.952 (5)
Na1—O4Bⁱⁱⁱ	2.86 (3)	Ba2—O2	2.952 (5)
Na1—O4B^iv	2.86 (3)	Ba2—O2ⁱ	2.952 (5)
Na1—O4B^v	2.86 (3)	Ba2—O4A^vi	3.047 (7)
Na1—O4A^vi	3.045 (17)	Ba2—O4A^vii	3.047 (7)
Na1—O4A^vii	3.045 (17)	Ba2—O4A^viii	3.047 (7)
Na1—O4A^viii	3.045 (17)	Fe1—O2ⁱⁱ	1.979 (4)
Na1—O2^ix	2.763 (17)	Fe1—O2^xv	1.979 (4)
Na1—O2^x	2.763 (17)	Fe1—O2^xvi	1.979 (4)
Na1—O2^xi	2.763 (17)	Fe1—O3^xiii	1.990 (4)
Ba1—O1ⁱ	2.753 (7)	Fe1—O3	1.990 (4)
Ba1—O1	2.753 (7)	Fe1—O3^xvii	1.990 (4)
Ba1—O1ⁱⁱ	2.753 (7)	Fe1—Ba1^xviii	3.6878 (19)
Ba1—O4Bⁱⁱⁱ	2.89 (3)	Fe1—Ba2^iv	3.7867 (6)
Ba1—O4B^iv	2.89 (3)	Fe1—Ba2^xv	3.7867 (6)
Ba1—O4B^v	2.89 (3)	Fe2—O4B^xix	1.946 (18)
Ba1—O4A^vi	2.902 (10)	Fe2—O4Bⁱⁱ	1.946 (18)
Ba1—O4A^vii	2.902 (10)	Fe2—O4B^xii	1.946 (18)
Ba1—O4A^viii	2.902 (10)	Fe2—O1^xx	1.984 (5)
Ba1—O2^ix	2.950 (6)	Fe2—O1^xxi	1.984 (5)
Ba1—O2^x	2.950 (6)	Fe2—O1^xxii	1.984 (5)
Ba1—O2^xi	2.950 (6)	Fe2—O4A^xix	1.982 (7)
Na2—O3^xii	2.604 (8)	Fe2—O4Aⁱⁱ	1.982 (7)
Na2—O3^xiii	2.604 (8)	Fe2—O4A^xii	1.982 (7)
Na2—O3^xiv	2.604 (8)	P—O4B	1.470 (18)
Na2—O2	3.004 (6)	P—O1^xxiii	1.493 (4)
Na2—O2ⁱ	3.004 (6)	P—O2^xxiii	1.506 (4)
Na2—O2ⁱⁱ	3.004 (6)	P—O3	1.526 (4)
Ba2—O3^xii	2.772 (5)	P—O4A	1.541 (7)

O1ⁱ—Na1—O1	94.9 (5)	O2^ix—Ba1—O2^xi	55.17 (13)
O1ⁱ—Na1—O1ⁱⁱ	94.9 (5)	O2^x—Ba1—O2^xi	55.17 (13)
O1—Na1—O1ⁱⁱ	94.9 (5)	O3^xii—Na2—O3^xiii	100.1 (3)
O1ⁱ—Na1—O4Bⁱⁱⁱ	58.0 (4)	O3^xii—Na2—O3^xiv	100.1 (3)
O1—Na1—O4Bⁱⁱⁱ	79.6 (4)	O3^xiii—Na2—O3^xiv	100.1 (3)
O1ⁱⁱ—Na1—O4Bⁱⁱⁱ	151.3 (7)	O3^xii—Na2—O2	83.46 (16)
O1ⁱ—Na1—O4B^iv	151.3 (7)	O3^xiii—Na2—O2	158.5 (4)
O1—Na1—O4B^iv	58.0 (4)	O3^xiv—Na2—O2	58.53 (12)
O1ⁱⁱ—Na1—O4B^iv	79.6 (4)	O3^xii—Na2—O2ⁱ	58.53 (12)
O4Bⁱⁱⁱ—Na1—O4B^iv	118.89 (19)	O3^xiii—Na2—O2ⁱ	83.46 (16)
O1ⁱ—Na1—O4B^v	79.6 (4)	O3^xiv—Na2—O2ⁱ	158.5 (4)
O1—Na1—O4B^v	151.3 (7)	O2—Na2—O2ⁱ	115.68 (18)
O1ⁱⁱ—Na1—O4B^v	58.0 (4)	O3^xii—Na2—O2ⁱⁱ	158.5 (4)
O4Bⁱⁱⁱ—Na1—O4B^v	118.89 (19)	O3^xiii—Na2—O2ⁱⁱ	58.53 (12)
O4B^iv—Na1—O4B^v	118.89 (19)	O3^xiv—Na2—O2ⁱⁱ	83.46 (16)
O1ⁱ—Na1—O4A^vi	46.9 (2)	O2—Na2—O2ⁱⁱ	115.68 (18)
O1—Na1—O4A^vi	107.0 (6)	O2ⁱ—Na2—O2ⁱⁱ	115.68 (18)
O1ⁱⁱ—Na1—O4A^vi	49.5 (3)	O3^xii—Ba2—O3^xiii	92.09 (15)
O1ⁱ—Na1—O4A^vii	49.5 (3)	O3^xii—Ba2—O3^xiv	92.09 (15)
O1—Na1—O4A^vii	46.9 (2)	O3^xiii—Ba2—O3^xiv	92.09 (15)
O1ⁱⁱ—Na1—O4A^vii	107.0 (6)	O3^xii—Ba2—O2ⁱⁱ	148.54 (14)
O1ⁱ—Na1—O4A^viii	107.0 (6)	O3^xiii—Ba2—O2ⁱⁱ	57.63 (12)
O1—Na1—O4A^viii	49.5 (3)	O3^xiv—Ba2—O2ⁱⁱ	81.64 (14)
O1ⁱⁱ—Na1—O4A^viii	46.9 (2)	O3^xii—Ba2—O2	81.64 (14)
O4A^vi—Na1—O4A^viii	81.1 (5)	O3^xiii—Ba2—O2	148.54 (14)
O4A^vii—Na1—O4A^viii	81.1 (5)	O3^xiv—Ba2—O2	57.63 (12)
O1ⁱ—Na1—O2^ix	97.97 (19)	O2ⁱⁱ—Ba2—O2	118.95 (3)
O1—Na1—O2^ix	104.0 (2)	O3^xii—Ba2—O2ⁱ	57.63 (12)
O1ⁱⁱ—Na1—O2^ix	156.0 (6)	O3^xiii—Ba2—O2ⁱ	81.64 (14)
O4B^iv—Na1—O2^ix	97.9 (6)	O3^xiv—Ba2—O2ⁱ	148.54 (14)
O4B^v—Na1—O2^ix	104.6 (6)	O2ⁱⁱ—Ba2—O2ⁱ	118.95 (3)
O4A^vi—Na1—O2^ix	134.2 (2)	O2—Ba2—O2ⁱ	118.95 (3)
O4A^vii—Na1—O2^ix	96.81 (16)	O3^xii—Ba2—O4A^vi	104.95 (16)
O4A^viii—Na1—O2^ix	144.2 (3)	O3^xiii—Ba2—O4A^vi	83.7 (2)
O1ⁱ—Na1—O2^x	156.0 (6)	O3^xiv—Ba2—O4A^vi	162.54 (16)
O1—Na1—O2^x	97.97 (19)	O2ⁱⁱ—Ba2—O4A^vi	81.80 (17)
O1ⁱⁱ—Na1—O2^x	104.0 (2)	O2—Ba2—O4A^vi	127.8 (2)
O4Bⁱⁱⁱ—Na1—O2^x	104.6 (6)	O2ⁱ—Ba2—O4A^vi	47.59 (16)
O4B^iv—Na1—O2^x	49.4 (4)	O3^xii—Ba2—O4A^vii	83.7 (2)
O4B^v—Na1—O2^x	97.9 (6)	O3^xiii—Ba2—O4A^vii	162.54 (16)
O4A^vi—Na1—O2^x	144.2 (3)	O3^xiv—Ba2—O4A^vii	104.95 (16)
O4A^vii—Na1—O2^x	134.2 (2)	O2ⁱⁱ—Ba2—O4A^vii	127.8 (2)
O4A^viii—Na1—O2^x	96.81 (16)	O2—Ba2—O4A^vii	47.59 (16)
O2^ix—Na1—O2^x	59.2 (4)	O2ⁱ—Ba2—O4A^vii	81.80 (17)
O1ⁱ—Na1—O2^xi	104.0 (2)	O4A^vi—Ba2—O4A^vii	81.1 (3)
O1—Na1—O2^xi	156.0 (6)	O3^xii—Ba2—O4A^viii	162.54 (17)
O1ⁱⁱ—Na1—O2^xi	97.97 (19)	O3^xiii—Ba2—O4A^viii	104.95 (16)
O4Bⁱⁱⁱ—Na1—O2^xi	97.9 (6)	O3^xiv—Ba2—O4A^viii	83.7 (2)
O4B^iv—Na1—O2^xi	104.6 (6)	O2ⁱⁱ—Ba2—O4A^viii	47.59 (16)
O4A^vi—Na1—O2^xi	96.81 (16)	O2—Ba2—O4A^viii	81.80 (17)
O4A^vii—Na1—O2^xi	144.2 (3)	O2ⁱ—Ba2—O4A^viii	127.8 (2)
O4A^viii—Na1—O2^xi	134.2 (2)	O4A^vi—Ba2—O4A^viii	81.1 (3)
O2^ix—Na1—O2^xi	59.2 (4)	O4A^vii—Ba2—O4A^viii	81.1 (3)
O2^x—Na1—O2^xi	59.2 (4)	O2ⁱⁱ—Fe1—O2^xv	87.3 (2)
O1ⁱ—Ba1—O1	100.10 (14)	O2ⁱⁱ—Fe1—O2^xvi	87.3 (2)
O1ⁱ—Ba1—O1ⁱⁱ	100.10 (14)	O2^xv—Fe1—O2^xvi	87.3 (2)
O1—Ba1—O1ⁱⁱ	100.10 (14)	O2ⁱⁱ—Fe1—O3^xiii	88.26 (18)
O1ⁱ—Ba1—O4Bⁱⁱⁱ	58.8 (4)	O2^xv—Fe1—O3^xiii	89.2 (2)
O1—Ba1—O4Bⁱⁱⁱ	80.9 (4)	O2^xvi—Fe1—O3^xiii	174.5 (2)
O1ⁱⁱ—Ba1—O4Bⁱⁱⁱ	158.5 (4)	O2ⁱⁱ—Fe1—O3	174.5 (2)
O1ⁱ—Ba1—O4B^iv	158.5 (4)	O2^xv—Fe1—O3	88.26 (18)
O1—Ba1—O4B^iv	58.8 (4)	O2^xvi—Fe1—O3	89.2 (2)
O1ⁱⁱ—Ba1—O4B^iv	80.9 (4)	O3^xiii—Fe1—O3	95.0 (2)
O4Bⁱⁱⁱ—Ba1—O4B^iv	116.8 (2)	O2ⁱⁱ—Fe1—O3^xvii	89.2 (2)
O1ⁱ—Ba1—O4B^v	80.9 (4)	O2^xv—Fe1—O3^xvii	174.5 (2)
O1—Ba1—O4B^v	158.5 (4)	O2^xvi—Fe1—O3^xvii	88.26 (18)
O1ⁱⁱ—Ba1—O4B^v	58.8 (4)	O3^xiii—Fe1—O3^xvii	95.0 (2)
O4Bⁱⁱⁱ—Ba1—O4B^v	116.8 (2)	O3—Fe1—O3^xvii	95.0 (2)
O4B^iv—Ba1—O4B^v	116.8 (2)	O4B^xix—Fe2—O4Bⁱⁱ	80.8 (9)
O1ⁱ—Ba1—O4A^vi	49.19 (16)	O4B^xix—Fe2—O4B^xii	80.8 (9)
O1—Ba1—O4A^vi	114.25 (19)	O4Bⁱⁱ—Fe2—O4B^xii	80.8 (9)
O1ⁱⁱ—Ba1—O4A^vi	51.94 (17)	O4B^xix—Fe2—O1^xx	169.5 (6)
O1ⁱ—Ba1—O4A^vii	51.94 (17)	O4Bⁱⁱ—Fe2—O1^xx	89.8 (8)
O1—Ba1—O4A^vii	49.19 (16)	O4B^xii—Fe2—O1^xx	93.0 (5)
O1ⁱⁱ—Ba1—O4A^vii	114.25 (19)	O4B^xix—Fe2—O1^xxi	93.0 (5)
O1ⁱ—Ba1—O4A^viii	114.25 (19)	O4Bⁱⁱ—Fe2—O1^xxi	169.5 (6)
O1—Ba1—O4A^viii	51.94 (17)	O4B^xii—Fe2—O1^xxi	89.8 (8)
O1ⁱⁱ—Ba1—O4A^viii	49.19 (16)	O1^xx—Fe2—O1^xxi	95.5 (3)
O4A^vi—Ba1—O4A^viii	86.1 (2)	O4B^xix—Fe2—O1^xxii	89.8 (8)
O4A^vii—Ba1—O4A^viii	86.1 (2)	O4Bⁱⁱ—Fe2—O1^xxii	93.0 (5)
O1ⁱ—Ba1—O2^ix	96.20 (14)	O4B^xii—Fe2—O1^xxii	169.5 (6)
O1—Ba1—O2^ix	102.04 (15)	O1^xx—Fe2—O1^xxii	95.5 (3)
O1ⁱⁱ—Ba1—O2^ix	149.64 (14)	O1^xxi—Fe2—O1^xxii	95.5 (3)
O4Bⁱⁱⁱ—Ba1—O2^ix	47.5 (4)	O1^xx—Fe2—O4A^xix	168.6 (3)
O4B^iv—Ba1—O2^ix	93.1 (4)	O1^xxi—Fe2—O4A^xix	77.4 (3)
O4B^v—Ba1—O2^ix	99.2 (4)	O1^xxii—Fe2—O4A^xix	94.1 (3)
O4A^vi—Ba1—O2^ix	132.27 (18)	O4B^xix—Fe2—O4Aⁱⁱ	78.2 (6)
O4A^vii—Ba1—O2^ix	95.97 (17)	O4Bⁱⁱ—Fe2—O4Aⁱⁱ	15.9 (5)
O4A^viii—Ba1—O2^ix	141.66 (18)	O4B^xii—Fe2—O4Aⁱⁱ	95.9 (8)
O1ⁱ—Ba1—O2^x	149.64 (14)	O1^xx—Fe2—O4Aⁱⁱ	94.1 (3)
O1—Ba1—O2^x	96.20 (14)	O1^xxi—Fe2—O4Aⁱⁱ	168.6 (3)
O1ⁱⁱ—Ba1—O2^x	102.04 (15)	O1^xxii—Fe2—O4Aⁱⁱ	77.4 (3)
O4Bⁱⁱⁱ—Ba1—O2^x	99.2 (4)	O4A^xix—Fe2—O4Aⁱⁱ	94.0 (3)
O4B^iv—Ba1—O2^x	47.5 (4)	O1^xx—Fe2—O4A^xii	77.4 (3)
O4B^v—Ba1—O2^x	93.1 (4)	O1^xxi—Fe2—O4A^xii	94.1 (3)
O4A^vi—Ba1—O2^x	141.66 (18)	O1^xxii—Fe2—O4A^xii	168.6 (3)
O4A^vii—Ba1—O2^x	132.27 (18)	O4A^xix—Fe2—O4A^xii	94.0 (3)
O4A^viii—Ba1—O2^x	95.97 (17)	O4Aⁱⁱ—Fe2—O4A^xii	94.0 (3)
O2^ix—Ba1—O2^x	55.17 (13)	O4B—P—O1^xxiii	119.9 (10)
O1ⁱ—Ba1—O2^xi	102.04 (15)	O4B—P—O2^xxiii	104.3 (11)
O1—Ba1—O2^xi	149.64 (14)	O1^xxiii—P—O2^xxiii	112.9 (3)
O1ⁱⁱ—Ba1—O2^xi	96.20 (14)	O4B—P—O3	97.0 (6)
O4Bⁱⁱⁱ—Ba1—O2^xi	93.1 (4)	O1^xxiii—P—O3	112.2 (3)
O4B^iv—Ba1—O2^xi	99.2 (4)	O2^xxiii—P—O3	109.2 (3)
O4B^v—Ba1—O2^xi	47.5 (4)	O4B—P—O4A	20.6 (6)
O4A^vi—Ba1—O2^xi	95.97 (16)	O1^xxiii—P—O4A	102.0 (4)
O4A^vii—Ba1—O2^xi	141.66 (18)	O2^xxiii—P—O4A	105.3 (4)
O4A^viii—Ba1—O2^xi	132.27 (18)	O3—P—O4A	115.1 (3)

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

Experimental details

Crystal data
Chemical formula	NaBaFe₂(PO₄)₃
M_r	556.94
Crystal system, space group	Cubic, P2₁3
Temperature (K)	293
a (Å)	9.796 (1)
V (Å³)	940.1 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	7.82
Crystal size (mm)	0.1 × 0.1 × 0.1

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.35, 0.46
No. of measured, independent and observed [I > 2σ(I)] reflections	2114, 657, 644
R_int	0.082
(sin θ/λ)_max (Å⁻¹)	0.702

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.025, 0.059, 0.92
No. of reflections	657
No. of parameters	70
No. of restraints	4
Δρ_max, Δρ_min (e Å⁻³)	0.57, −0.49
Absolute structure	Flack (1983), with how many Friedel pairs?
Absolute structure parameter	−0.03 (3)

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1998).

Selected bond angles (º) top

O4Bⁱ—Fe2—O1ⁱⁱ

89.8 (8)

O3—P—O4A

115.1 (3)

Symmetry codes: (i) z, x, y; (ii) −z+3/2, −x+1, y−1/2.

References

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