Caesium europium(III) polyphosphate, CsEu(PO3)4

Zhu, J.; Cheng, W.-D.; Zhang, H.

doi:10.1107/S1600536809036058

inorganic compounds

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ISSN: 2056-9890

Volume 65| Part 10| October 2009| Page i70

doi:10.1107/S1600536809036058

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Caesium europium(III) polyphosphate, CsEu(PO₃)₄

Jing Zhu,^a ^* Wen-Dan Cheng ^b and Hao Zhang ^b

^aDepartment of Materials Science and Engineering, Yunnan University, Kunming, Yunnan 650091, People's Republic of China, and ^bState Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, People's Republic of China
^*Correspondence e-mail: jzhu@ynu.edu.cn

(Received 1 September 2009; accepted 7 September 2009; online 12 September 2009)

Caesium europium polyphosphate, CsEu(PO₃)₄, was synthesized by a high-temperature solution reaction. Its structure is charaterized by a three-dimensional framework made up of double PO₄ spiral chains and EuO₈ and CsO₁₁ polyhedra.

Related literature

For the structures, properties and applications of condensed alkaline metal–rare earth polyphosphates with the general formula MLn(PO₃)₄ (M = alkali metal, Ln = rare earth metal), see: Chinn & Hong (1975 ); Ettis et al. (2003 ); Hong (1975 ); Koizumi (1976 ); Koizumi & Nakano (1978 ); Maksimova et al. (1982 ); Naïli & Mhiri (2005 ); Otsuka et al. (1977 ); Palkina et al. (1978 ); Rekik et al. (2004 ); Tsujimoto et al. (1977 ).

Experimental

Crystal data

CsEu(PO₃)₄
M_r = 600.75
Monoclinic, P 2₁ /n
a = 10.3571 (9) Å
b = 8.9615 (5) Å
c = 11.1957 (8) Å
β = 106.354 (3)°
V = 997.09 (13) Å³
Z = 4
Mo Kα radiation
μ = 10.60 mm⁻¹
T = 293 K
0.25 × 0.20 × 0.15 mm

Data collection

Bruker P4 diffractometer
Absorption correction: ψ-scan (XSCANS; Bruker, 1996 ) T_min = 0.545, T_max = 1.000
7446 measured reflections
2284 independent reflections
2185 reflections with I > 2σ(I)
R_int = 0.025
3 standard reflections every 97 reflections intensity decay: none

Refinement

R[F² > 2σ(F²)] = 0.019
wR(F²) = 0.048
S = 1.00
2284 reflections
164 parameters
Δρ_max = 1.16 e Å⁻³
Δρ_min = −1.17 e Å⁻³

Data collection: XSCANS (Bruker, 1996); cell refinement: XSCANS; data reduction: SHELXTL (Sheldrick, 2008 ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablock I. DOI: 10.1107/S1600536809036058/bt5050sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809036058/bt5050Isup2.hkl

checkCIF report

Comment top

Condensed alkaline metal-rare earth polyphosphates with the general formula MLn(PO₃)₄ (M = alkali metal, Ln = rare earth metal) possess various structures (Ettis et al., 2003; Rekik et al., 2004) and desirable optical properties (Chinn et al., 1975; Otsuka et al., 1977; Tsujimoto et al., 1977; Hong et al., 1975; Koizumi et al., 1976). Furthermore, their chemical and thermal stability ensures the feasibility of the industrial applications. For this reason some polyphosphates (Naïli et al., 2005; Palkina et al., 1978; Maksimova et al., 1982) were synthesized and investigated in the Cs–Ln–P–O system as an important potential. However, polyphosphates containing europium have not to date been fully explored in the system. Our exploration on the system afforded caesium europium polyphosphate CsEu(PO₃)₄. We report herein the synthesis and crystal structure of CsEu(PO₃)₄.

Crystallographic data and structural refinement of CsEu(PO₃)₄ are summarized in Table 1. The atomic coordinates and thermal parameters are listed in Table 2. Selected bond lengths and angles are given in Table 3.

The structure of crystal CsEu(PO₃)₄ is shown in Fig. 1. It belongs to the monoclinic space group P2₁/n, which is isostructural with CsGd(PO₃)₄ (Naïli et al., 2005). The crystallographically distinct atoms of the asymmetric unit in the structure are one caesium, one europium, four phosphorus, and twelve oxygen atoms. It is described as a three-dimensional framework made up from double PO₄ spiral chains and Cs- and Eu-polyhedra. As illustrated in Fig. 2, the double PO₄ spiral chains have the same repeating unit (eight PO₄ tetrahedra) as single one of CsNd(PO₃)₄ (Koizumi et al., 1978). These spiral chains are linked by EuO₈ and CsO₁₁ polyhedra. In addition, comparing with CsNd(PO₃)₄, the different characteristics are noted in the coordination environments of the cations. The Eu cation is eight-coordinated with the Eu—O band distances ranging from 2.344 (3) to 2.471 (3) Å. Each EuO₈ polyhedron is corner- and face-connected with two and two CsO₁₁ polyhedra, respectively (Fig. 3). The isolation of EuO₈ polyhedra gives rise to the large Eu—Eu distances, the shortest of which is 5.7415 (3) Å. The Cs cation is coordinated by eleven oxygen atoms, and the large range of the Cs—O bond distances implies that CsO₁₁ polyhedra are distorted. Neighboring two CsO₁₁ polyhedra are linked by corner-sharing (Fig. 4).

Related literature top

For the structures and properties and applications of condensed alkaline metal–rare earth polyphosphates with the general formula MLn(PO₃)₄ (M = alkali metal, Ln = rare earth metal), see: Chinn & Hong (1975); Ettis et al. (2003); Hong (1975); Koizumi (1976); Koizumi & Nakano (1978); Maksimova et al. (1982); Naïli & Mhiri (2005); Otsuka et al. (1977); Palkina et al. (1978); Rekik et al. (2004); Tsujimoto et al. (1977).

Experimental top

The title compound was prepared by the high temperature solution reaction, using analytical reagents Cs₂CO₃, Eu₂O₃, and NH₄H₂PO₄ in the molar ratio of Cs/Eu/P = 7:1:12. Starting mixtures were finely ground in an agate mortar to ensure the best homogeneity and reactivity, then placed in a platinum crucible and heated at 373 K for 4 h. Afterwards, the mixtures were reground and heated to 973 K for 24 h. Finally, the temperature was cooled to 773 K at a rate of 2 K/h and air-quenched to room temperature. A few colorless and block-shaped crystals were obtained from the melt of the mixture.

Computing details top

Data collection: XSCANS (Bruker, 1996); cell refinement: XSCANS (Bruker, 1996); data reduction: SHELXTL (Sheldrick, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top

Fig. 1. Displacement ellipsoid plot (50% probability) of CsEu(PO₃)₄.

Caesium europium(III) polyphosphate top

Crystal data top

CsEu(PO₃)₄	F(000) = 1096
M_r = 600.75	D_x = 4.002 Mg m⁻³
Monoclinic, P2₁/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 2827 reflections
a = 10.3571 (9) Å	θ = 2.3–27.5°
b = 8.9615 (5) Å	µ = 10.60 mm⁻¹
c = 11.1957 (8) Å	T = 293 K
β = 106.354 (3)°	Prism, colorless
V = 997.09 (13) Å³	0.25 × 0.20 × 0.15 mm
Z = 4

Data collection top

Bruker P4 diffractometer	2284 independent reflections
Radiation source: fine-focus sealed tube	2185 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.025
Detector resolution: 14.6306 pixels mm^-1	θ_max = 27.5°, θ_min = 2.4°
ω scans	h = −10→13
Absorption correction: ψ scan (XSCANS; Bruker, 1996)	k = −10→11
T_min = 0.545, T_max = 1.000	l = −14→14
7446 measured reflections

Refinement top

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)] = 0.019	w = 1/[σ²(F_o²) + (0.0273P)² + 2.176P] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.048	(Δ/σ)_max = 0.001
S = 1.00	Δρ_max = 1.16 e Å⁻³
2284 reflections	Δρ_min = −1.17 e Å⁻³
164 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0154 (3)

Crystal data top

CsEu(PO₃)₄	V = 997.09 (13) Å³
M_r = 600.75	Z = 4
Monoclinic, P2₁/n	Mo Kα radiation
a = 10.3571 (9) Å	µ = 10.60 mm⁻¹
b = 8.9615 (5) Å	T = 293 K
c = 11.1957 (8) Å	0.25 × 0.20 × 0.15 mm
β = 106.354 (3)°

Data collection top

Bruker P4 diffractometer	2284 independent reflections
Absorption correction: ψ scan (XSCANS; Bruker, 1996)	2185 reflections with I > 2σ(I)
T_min = 0.545, T_max = 1.000	R_int = 0.025
7446 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.019	164 parameters
wR(F²) = 0.048	0 restraints
S = 1.00	Δρ_max = 1.16 e Å⁻³
2284 reflections	Δρ_min = −1.17 e Å⁻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.

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 > 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 (Å²) top

	x	y	z	U_iso*/U_eq
Eu	0.498050 (16)	0.226449 (17)	0.180852 (15)	0.00580 (8)
Cs	0.67980 (2)	−0.06549 (3)	0.45979 (2)	0.01775 (9)
P1	0.45959 (9)	−0.17482 (9)	0.13333 (8)	0.00609 (17)
P2	0.75501 (8)	0.02838 (9)	0.78552 (8)	0.00606 (17)
P3	0.67259 (9)	0.39350 (9)	0.47427 (8)	0.00652 (17)
P4	0.64481 (9)	−0.40738 (9)	0.25829 (8)	0.00669 (17)
O1	0.8311 (3)	0.0968 (3)	0.7052 (2)	0.0103 (5)
O2	0.8623 (2)	−0.0428 (3)	0.9043 (2)	0.0084 (5)
O3	0.6485 (3)	−0.0823 (3)	0.7252 (2)	0.0097 (5)
O4	0.5366 (2)	−0.0336 (3)	0.1654 (2)	0.0112 (5)
O5	0.3125 (3)	0.1627 (3)	0.0137 (2)	0.0122 (5)
O6	0.5645 (3)	0.2902 (3)	0.4047 (2)	0.0110 (5)
O7	0.5603 (3)	0.2458 (3)	−0.0102 (2)	0.0110 (5)
O8	0.5213 (2)	−0.2937 (3)	0.2424 (2)	0.0097 (5)
O9	0.6665 (3)	−0.4514 (3)	0.4006 (2)	0.0116 (5)
O10	0.7367 (2)	0.1781 (3)	0.2529 (2)	0.0120 (5)
O11	0.6003 (3)	0.4610 (3)	0.1767 (2)	0.0115 (5)
O12	0.6881 (2)	0.1588 (3)	0.8470 (2)	0.0085 (5)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Eu	0.00621 (11)	0.00206 (10)	0.00886 (11)	−0.00049 (5)	0.00168 (7)	−0.00068 (5)
Cs	0.02071 (15)	0.01835 (13)	0.01329 (14)	0.00425 (9)	0.00334 (10)	−0.00079 (8)
P1	0.0062 (4)	0.0021 (4)	0.0096 (4)	0.0002 (3)	0.0017 (3)	−0.0003 (3)
P2	0.0059 (4)	0.0031 (4)	0.0094 (4)	−0.0003 (3)	0.0026 (3)	0.0003 (3)
P3	0.0070 (4)	0.0036 (4)	0.0082 (4)	0.0000 (3)	0.0009 (3)	0.0006 (3)
P4	0.0074 (4)	0.0025 (4)	0.0094 (4)	0.0003 (3)	0.0011 (3)	0.0006 (3)
O1	0.0109 (12)	0.0084 (11)	0.0128 (12)	−0.0017 (9)	0.0056 (10)	0.0008 (9)
O2	0.0074 (11)	0.0076 (11)	0.0101 (12)	0.0008 (9)	0.0025 (10)	0.0017 (9)
O3	0.0114 (12)	0.0069 (11)	0.0104 (12)	−0.0026 (9)	0.0020 (10)	−0.0032 (9)
O4	0.0085 (12)	0.0052 (11)	0.0203 (14)	−0.0010 (9)	0.0048 (10)	−0.0013 (10)
O5	0.0105 (13)	0.0127 (12)	0.0133 (13)	−0.0055 (10)	0.0032 (10)	−0.0025 (10)
O6	0.0111 (13)	0.0081 (12)	0.0127 (13)	−0.0027 (9)	0.0016 (10)	−0.0037 (9)
O7	0.0109 (13)	0.0108 (11)	0.0116 (13)	−0.0016 (9)	0.0035 (10)	−0.0014 (9)
O8	0.0092 (12)	0.0066 (11)	0.0130 (13)	0.0032 (9)	0.0028 (10)	0.0032 (9)
O9	0.0189 (13)	0.0047 (11)	0.0104 (12)	−0.0017 (10)	0.0027 (10)	−0.0002 (9)
O10	0.0085 (12)	0.0084 (12)	0.0177 (13)	0.0018 (9)	0.0015 (10)	−0.0041 (10)
O11	0.0165 (13)	0.0037 (11)	0.0152 (13)	−0.0027 (9)	0.0063 (10)	−0.0019 (9)
O12	0.0053 (11)	0.0028 (10)	0.0171 (13)	−0.0006 (8)	0.0024 (10)	−0.0022 (9)

Geometric parameters (Å, º) top

Eu—O5	2.344 (3)	P2—O1	1.485 (2)
Eu—O11	2.360 (2)	P2—O3	1.495 (3)
Eu—O4	2.379 (2)	P2—O2	1.605 (3)
Eu—O7	2.408 (3)	P2—O12	1.609 (2)
Eu—O10	2.413 (2)	P2—Euⁱⁱ	3.5752 (9)
Eu—O1ⁱ	2.416 (2)	P3—O5^viii	1.479 (3)
Eu—O3ⁱⁱ	2.445 (2)	P3—O6	1.492 (3)
Eu—O6	2.471 (3)	P3—O2^ix	1.607 (2)
Eu—P2ⁱⁱ	3.5752 (9)	P3—O9^x	1.609 (3)
Eu—P3	3.5994 (9)	P4—O10^iv	1.481 (3)
Eu—Cs	4.1024 (3)	P4—O11^xi	1.484 (3)
Eu—Csⁱⁱⁱ	4.4773 (4)	P4—O9	1.594 (3)
Cs—O3	3.083 (2)	P4—O8	1.605 (3)
Cs—O11^iv	3.089 (2)	P4—Cs^iv	3.7102 (9)
Cs—O7^iv	3.093 (3)	O1—Eu^viii	2.416 (2)
Cs—O1	3.114 (3)	O2—P3^v	1.607 (2)
Cs—O4	3.224 (3)	O3—Euⁱⁱ	2.445 (2)
Cs—O8	3.249 (3)	O3—Csⁱⁱ	3.693 (3)
Cs—O12^v	3.315 (2)	O5—P3ⁱ	1.479 (3)
Cs—O10	3.354 (3)	O7—P1^vi	1.479 (3)
Cs—O6	3.399 (3)	O7—Csⁱⁱⁱ	3.093 (3)
Cs—O9	3.517 (2)	O9—P3^xi	1.609 (3)
Cs—O10^iv	3.586 (3)	O10—P4ⁱⁱⁱ	1.481 (3)
Cs—P2	3.6075 (9)	O10—Csⁱⁱⁱ	3.586 (3)
P1—O7^vi	1.479 (3)	O11—P4^x	1.484 (3)
P1—O4	1.485 (2)	O11—Csⁱⁱⁱ	3.089 (2)
P1—O8	1.611 (3)	O12—P1ⁱⁱ	1.612 (2)
P1—O12ⁱⁱ	1.612 (2)	O12—Cs^ix	3.315 (2)
P1—Cs^vii	3.7970 (9)

O5—Eu—O11	118.20 (9)	O4—Cs—O10^iv	60.36 (6)
O5—Eu—O4	79.62 (9)	O8—Cs—O10^iv	42.64 (6)
O11—Eu—O4	141.79 (8)	O12^v—Cs—O10^iv	79.81 (6)
O5—Eu—O7	70.90 (9)	O10—Cs—O10^iv	80.580 (8)
O11—Eu—O7	71.60 (8)	O6—Cs—O10^iv	128.21 (6)
O4—Eu—O7	85.04 (9)	O9—Cs—O10^iv	41.28 (6)
O5—Eu—O10	139.03 (9)	O3—Cs—P2	24.24 (5)
O11—Eu—O10	75.15 (9)	O11^iv—Cs—P2	120.18 (5)
O4—Eu—O10	70.81 (8)	O7^iv—Cs—P2	90.79 (5)
O7—Eu—O10	78.72 (9)	O1—Cs—P2	24.12 (4)
O5—Eu—O1ⁱ	78.33 (9)	O4—Cs—P2	156.80 (5)
O11—Eu—O1ⁱ	75.98 (8)	O8—Cs—P2	145.49 (5)
O4—Eu—O1ⁱ	142.22 (8)	O12^v—Cs—P2	65.31 (5)
O7—Eu—O1ⁱ	115.59 (9)	O10—Cs—P2	121.11 (5)
O10—Eu—O1ⁱ	141.10 (9)	O6—Cs—P2	85.97 (5)
O5—Eu—O3ⁱⁱ	75.28 (8)	O9—Cs—P2	113.94 (4)
O11—Eu—O3ⁱⁱ	144.64 (8)	O10^iv—Cs—P2	142.83 (4)
O4—Eu—O3ⁱⁱ	69.56 (8)	O7^vi—P1—O4	121.10 (15)
O7—Eu—O3ⁱⁱ	140.72 (8)	O7^vi—P1—O8	110.06 (14)
O10—Eu—O3ⁱⁱ	117.57 (9)	O4—P1—O8	108.01 (15)
O1ⁱ—Eu—O3ⁱⁱ	75.37 (8)	O7^vi—P1—O12ⁱⁱ	106.09 (14)
O5—Eu—O6	142.87 (8)	O4—P1—O12ⁱⁱ	110.89 (13)
O11—Eu—O6	79.39 (9)	O8—P1—O12ⁱⁱ	98.32 (13)
O4—Eu—O6	107.21 (9)	O7^vi—P1—Cs^vii	51.19 (10)
O7—Eu—O6	144.72 (9)	O4—P1—Cs^vii	157.90 (11)
O10—Eu—O6	74.71 (9)	O8—P1—Cs^vii	93.73 (10)
O1ⁱ—Eu—O6	74.81 (9)	O12ⁱⁱ—P1—Cs^vii	60.52 (9)
O3ⁱⁱ—Eu—O6	73.47 (8)	O7^vi—P1—Cs	152.14 (11)
O5—Eu—P2ⁱⁱ	57.86 (6)	O4—P1—Cs	54.51 (10)
O11—Eu—P2ⁱⁱ	156.53 (6)	O8—P1—Cs	56.39 (10)
O4—Eu—P2ⁱⁱ	61.64 (6)	O12ⁱⁱ—P1—Cs	100.29 (10)
O7—Eu—P2ⁱⁱ	121.82 (6)	Cs^vii—P1—Cs	143.55 (2)
O10—Eu—P2ⁱⁱ	124.21 (6)	O1—P2—O3	116.76 (15)
O1ⁱ—Eu—P2ⁱⁱ	80.66 (6)	O1—P2—O2	107.71 (14)
O3ⁱⁱ—Eu—P2ⁱⁱ	19.06 (6)	O3—P2—O2	111.15 (14)
O6—Eu—P2ⁱⁱ	92.51 (6)	O1—P2—O12	108.98 (14)
O5—Eu—P3	156.63 (6)	O3—P2—O12	108.82 (14)
O11—Eu—P3	62.28 (6)	O2—P2—O12	102.45 (13)
O4—Eu—P3	114.99 (6)	O1—P2—Euⁱⁱ	149.02 (11)
O7—Eu—P3	126.11 (6)	O3—P2—Euⁱⁱ	32.27 (10)
O10—Eu—P3	64.27 (6)	O2—P2—Euⁱⁱ	90.91 (9)
O1ⁱ—Eu—P3	79.40 (6)	O12—P2—Euⁱⁱ	90.11 (9)
O3ⁱⁱ—Eu—P3	92.32 (6)	O1—P2—Cs	58.96 (10)
O6—Eu—P3	18.85 (6)	O3—P2—Cs	57.81 (10)
P2ⁱⁱ—Eu—P3	111.36 (2)	O2—P2—Cs	130.28 (9)
O5—Eu—Cs	123.34 (6)	O12—P2—Cs	127.26 (10)
O11—Eu—Cs	118.09 (6)	Euⁱⁱ—P2—Cs	90.08 (2)
O4—Eu—Cs	51.71 (6)	O5^viii—P3—O6	118.20 (15)
O7—Eu—Cs	122.82 (6)	O5^viii—P3—O2^ix	107.64 (14)
O10—Eu—Cs	54.82 (6)	O6—P3—O2^ix	110.36 (14)
O1ⁱ—Eu—Cs	121.45 (6)	O5^viii—P3—O9^x	109.94 (14)
O3ⁱⁱ—Eu—Cs	62.80 (6)	O6—P3—O9^x	110.66 (15)
O6—Eu—Cs	55.84 (6)	O2^ix—P3—O9^x	98.14 (13)
P2ⁱⁱ—Eu—Cs	72.864 (15)	O5^viii—P3—Eu	109.19 (11)
P3—Eu—Cs	64.255 (15)	O6—P3—Eu	32.35 (10)
O5—Eu—Csⁱⁱⁱ	110.19 (6)	O2^ix—P3—Eu	138.19 (9)
O11—Eu—Csⁱⁱⁱ	40.47 (6)	O9^x—P3—Eu	87.37 (10)
O4—Eu—Csⁱⁱⁱ	103.03 (6)	O5^viii—P3—Cs	69.17 (11)
O7—Eu—Csⁱⁱⁱ	40.98 (6)	O6—P3—Cs	51.61 (10)
O10—Eu—Csⁱⁱⁱ	52.97 (6)	O2^ix—P3—Cs	113.51 (9)
O1ⁱ—Eu—Csⁱⁱⁱ	113.24 (6)	O9^x—P3—Cs	147.29 (10)
O3ⁱⁱ—Eu—Csⁱⁱⁱ	170.28 (6)	Eu—P3—Cs	63.810 (14)
O6—Eu—Csⁱⁱⁱ	103.77 (6)	O10^iv—P4—O11^xi	118.71 (15)
P2ⁱⁱ—Eu—Csⁱⁱⁱ	160.739 (15)	O10^iv—P4—O9	108.98 (15)
P3—Eu—Csⁱⁱⁱ	85.139 (15)	O11^xi—P4—O9	110.52 (14)
Cs—Eu—Csⁱⁱⁱ	107.796 (7)	O10^iv—P4—O8	108.41 (14)
O3—Cs—O11^iv	140.63 (7)	O11^xi—P4—O8	109.63 (15)
O3—Cs—O7^iv	96.87 (7)	O9—P4—O8	98.71 (14)
O11^iv—Cs—O7^iv	53.65 (6)	O10^iv—P4—Cs^iv	64.61 (11)
O3—Cs—O1	48.36 (6)	O11^xi—P4—Cs^iv	54.28 (10)
O11^iv—Cs—O1	98.19 (7)	O9—P4—Cs^iv	127.28 (10)
O7^iv—Cs—O1	84.17 (7)	O8—P4—Cs^iv	133.76 (10)
O3—Cs—O4	147.89 (6)	O10^iv—P4—Cs	71.77 (11)
O11^iv—Cs—O4	71.25 (6)	O11^xi—P4—Cs	167.85 (11)
O7^iv—Cs—O4	111.18 (6)	O9—P4—Cs	68.87 (9)
O1—Cs—O4	146.42 (6)	O8—P4—Cs	59.27 (10)
O3—Cs—O8	121.57 (6)	Cs^iv—P4—Cs	136.34 (2)
O11^iv—Cs—O8	88.01 (6)	P2—O1—Eu^viii	149.05 (16)
O7^iv—Cs—O8	91.30 (6)	P2—O1—Cs	96.92 (12)
O1—Cs—O8	167.93 (6)	Eu^viii—O1—Cs	113.90 (9)
O4—Cs—O8	45.55 (6)	P2—O2—P3^v	125.03 (15)
O3—Cs—O12^v	58.05 (6)	P2—O3—Euⁱⁱ	128.67 (14)
O11^iv—Cs—O12^v	98.84 (6)	P2—O3—Cs	97.95 (11)
O7^iv—Cs—O12^v	45.19 (6)	Euⁱⁱ—O3—Cs	133.38 (9)
O1—Cs—O12^v	76.10 (6)	P2—O3—Csⁱⁱ	117.46 (12)
O4—Cs—O12^v	136.03 (6)	Euⁱⁱ—O3—Csⁱⁱ	81.12 (7)
O8—Cs—O12^v	92.77 (6)	Cs—O3—Csⁱⁱ	76.82 (6)
O3—Cs—O10	141.66 (6)	P1—O4—Eu	139.70 (15)
O11^iv—Cs—O10	46.43 (6)	P1—O4—Cs	103.46 (12)
O7^iv—Cs—O10	99.72 (6)	Eu—O4—Cs	92.90 (8)
O1—Cs—O10	99.37 (6)	P3ⁱ—O5—Eu	146.62 (16)
O4—Cs—O10	49.90 (6)	P3—O6—Eu	128.80 (15)
O8—Cs—O10	92.42 (6)	P3—O6—Cs	108.25 (13)
O12^v—Cs—O10	144.62 (6)	Eu—O6—Cs	87.17 (7)
O3—Cs—O6	95.38 (6)	P1^vi—O7—Eu	142.64 (15)
O11^iv—Cs—O6	96.23 (6)	P1^vi—O7—Csⁱⁱⁱ	106.94 (12)
O7^iv—Cs—O6	142.10 (6)	Eu—O7—Csⁱⁱⁱ	108.31 (9)
O1—Cs—O6	77.64 (6)	P4—O8—P1	129.62 (16)
O4—Cs—O6	72.20 (6)	P4—O8—Cs	95.59 (11)
O8—Cs—O6	112.13 (6)	P1—O8—Cs	99.22 (11)
O12^v—Cs—O6	151.27 (6)	P4—O9—P3^xi	134.46 (17)
O10—Cs—O6	52.07 (6)	P4—O9—Cs	86.11 (10)
O3—Cs—O9	97.16 (6)	P3^xi—O9—Cs	139.40 (13)
O11^iv—Cs—O9	88.72 (6)	P4ⁱⁱⁱ—O10—Eu	149.26 (16)
O7^iv—Cs—O9	58.85 (6)	P4ⁱⁱⁱ—O10—Cs	91.87 (12)
O1—Cs—O9	127.52 (6)	Eu—O10—Cs	89.14 (7)
O4—Cs—O9	84.95 (6)	P4ⁱⁱⁱ—O10—Csⁱⁱⁱ	85.12 (11)
O8—Cs—O9	41.82 (6)	Eu—O10—Csⁱⁱⁱ	94.52 (8)
O12^v—Cs—O9	51.48 (6)	Cs—O10—Csⁱⁱⁱ	176.32 (8)
O10—Cs—O9	121.00 (6)	P4^x—O11—Eu	139.40 (15)
O6—Cs—O9	153.49 (6)	P4^x—O11—Csⁱⁱⁱ	102.77 (12)
O3—Cs—O10^iv	136.01 (6)	Eu—O11—Csⁱⁱⁱ	109.80 (8)
O11^iv—Cs—O10^iv	51.06 (6)	P2—O12—P1ⁱⁱ	131.54 (16)
O7^iv—Cs—O10^iv	53.89 (6)	P2—O12—Cs^ix	132.22 (12)
O1—Cs—O10^iv	136.86 (6)	P1ⁱⁱ—O12—Cs^ix	94.44 (10)

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

Experimental details

Crystal data
Chemical formula	CsEu(PO₃)₄
M_r	600.75
Crystal system, space group	Monoclinic, P2₁/n
Temperature (K)	293
a, b, c (Å)	10.3571 (9), 8.9615 (5), 11.1957 (8)
β (°)	106.354 (3)
V (Å³)	997.09 (13)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	10.60
Crystal size (mm)	0.25 × 0.20 × 0.15

Data collection
Diffractometer	Bruker P4 diffractometer
Absorption correction	ψ scan (XSCANS; Bruker, 1996)
T_min, T_max	0.545, 1.000
No. of measured, independent and observed [I > 2σ(I)] reflections	7446, 2284, 2185
R_int	0.025
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.019, 0.048, 1.00
No. of reflections	2284
No. of parameters	164
Δρ_max, Δρ_min (e Å⁻³)	1.16, −1.17

Computer programs: XSCANS (Bruker, 1996), SHELXTL (Sheldrick, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008).

Acknowledgements

This investigation was based on work supported by the Foundation of Yunnan University (project No. 2007Q013B), the National Natural Science Foundation of China (project No. 20901066) and the Education Science Foundation of Yunnan Province. We thank Dr Qingyan Liu for fruitful discussions concerning the crystal structure.

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