CsMgPO4

Strutynska, N.Yu.; Zatovsky, I.V.; Baumer, V.N.; Slobodyanik, N.S.

doi:10.1107/S1600536809025434

inorganic compounds

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Volume 65| Part 8| August 2009| Page i58

doi:10.1107/S1600536809025434

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CsMgPO₄

Nataliya Yu. Strutynska,^a ^* Igor V. Zatovsky,^a Vyacheslav N. Baumer ^b and Nikolay S. Slobodyanik ^a

^aDepartment of Inorganic Chemistry, Taras Shevchenko National University, 64 Volodymyrska Street, 01601 Kyiv, Ukraine, and ^bSTC `Institute for Single Crystals', NAS of Ukraine, 60 Lenin Avenue, 61001 Kharkiv, Ukraine
^*Correspondence e-mail: Strutynska_N@bigmir.net

(Received 26 June 2009; accepted 1 July 2009; online 4 July 2009)

Caesium magnesium orthophosphate is built up from MgO₄ and PO₄ tetrahedra (both with . m. symmetry) linked together by corners, forming a three-dimensional framework. The Cs atoms have .m. site symmetry and are located in hexagonal channels running along the a- and b-axis directions.

Related literature

For the properties of double phosphates A^IB^IIPO₄ (A^I = alkali metal; B^II = Ca, Sr, Ba, Zn, Cd, Pb) such as ferroelectric and non-linear optical behaviour, see: Blum et al. (1984 ); Elouadi et al. (1984 ); Sawada et al. (2003 ). Several polymorphs have been found among orthophosphates containing Cs and divalent metals, see: Blum et al. (1986 ) for CsZnPO₄. In contrast, CsMnPO₄ occurs in only one type, see: Yakubovich et al. (1990 ). The title compound is isotypic with the Pnma form of CsZnPO₄. For related structures, see: Yakubovich et al. (1990); Blum et al. (1986); Zaripov et al. (2008 ).

Experimental

Crystal data

CsMgPO₄
M_r = 252.19
Orthorhombic, P n m a
a = 8.9327 (2) Å
b = 5.5277 (2) Å
c = 9.6487 (3) Å
V = 476.43 (3) Å³
Z = 4
Mo Kα radiation
μ = 8.13 mm⁻¹
T = 293 K
0.12 × 0.10 × 0.08 mm

Data collection

Oxford Diffraction Xcalibur-3 diffractometer
Absorption correction: multi-scan (Blessing, 1995 ) T_min = 0.413, T_max = 0.503
8753 measured reflections
1137 independent reflections
874 reflections with I > 2σ(I)
R_int = 0.027

Refinement

R[F² > 2σ(F²)] = 0.021
wR(F²) = 0.047
S = 1.00
1137 reflections
41 parameters
Δρ_max = 1.23 e Å⁻³
Δρ_min = −1.02 e Å⁻³

Table 1
Selected bond lengths (Å)

Cs1—O2	3.1951 (9)
Cs1—O2ⁱ	3.2166 (9)
Cs1—O3ⁱⁱ	3.4476 (11)
Cs1—O1ⁱ	3.5224 (11)
Cs1—O1ⁱⁱ	3.6496 (11)
Cs1—O3ⁱⁱⁱ	3.6968 (18)
Mg1—O1	1.8847 (13)
Mg1—O3^iv	1.8932 (13)
Mg1—O2^v	1.9228 (8)
P1—O1	1.5056 (13)
P1—O3	1.5138 (13)
P1—O2	1.5249 (8)
Symmetry codes: (i) -x+1, -y, -z+1; (ii) $[-x+{\script{1\over 2}}, -y+1, z+{\script{1\over 2}}]$ ; (iii) $[x+{\script{1\over 2}}, y, -z+{\script{3\over 2}}]$ ; (iv) $[x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}]$ ; (v) $[-x+{\script{1\over 2}}, -y, z-{\script{1\over 2}}]$ .

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 $[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]$ ); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2006 $[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]$ ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ) and enCIFer (Allen et al., 2004 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809025434/mg2075sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809025434/mg2075Isup2.hkl

checkCIF report

Comment top

Double phosphates A^IB^IIPO₄ (A^I = alkali metal; B^II = Ca, Sr, Ba, Zn, Cd, Pb) exhibit important properties such as ferroelectric and nonlinear optical behaviour (Blum et al., 1984; Elouadi et al., 1984; Sawada et al., 2003). Among some orthophosphates containing Cs and divalent metals, several polymorphs have been found. For instance, CsZnPO₄ occurs in a monoclinic (space group P2₁/a) and two orthorhombic types (space groups Pna2₁ and Pnma) (Blum et al., 1986). In contrast, CsMnPO₄ occurs in only one type (space group Pna2₁) (Yakubovich et al., 1990). CsMgPO₄, reported here, is isotypic with the Pnma form of CsZnPO₄.

Except for O2 (8d), all atoms are in special positions (4c) (Fig. 1). Each MgO₄ tetrahedron is linked with four PO₄ tetrahedra via common vertices, resulting in a three-dimensional framework with two types of hexagonal channels, filled by Cs atoms, along the a and b directions (Fig. 2). With a cut-off distance of 3.7 Å, the Cs atoms are 11-coordinate. In general, the principles of crystal structure building are equivalent to those in CsM^IIPO₄ (M^II = Mn, Zn) (Yakubovich et al., 1990; Blum et al., 1986) and CsLi_0.5Al_0.5PO₄ (Zapirov et al., 2008).

Related literature top

For the properties of double phosphates A^IB^IIPO₄ (A^I = alkali metal; B^II = Ca, Sr, Ba, Zn, Cd, Pb) such as ferroelectric and non-linearoptical behaviour, see: Blum et al. (1984); Elouadi et al. (1984); Sawada et al. (2003). Several polymorphs have been found among orthophosphates containing Cs and divalent metals, see: Blum et al. (1986) for CsZnPO₄. In contrast, CsMnPO₄ occurs in only one type, see: Yakubovich et al. (1990). The title compound is isotypic with the Pnma form of CsZnPO₄. For related structures, see: Yakubovich et al., 1990); Blum et al., 1986); Zaripov et al. (2008).

Experimental top

In the course of investigating the Cs₂O–MgO–Bi₂O₃–P₂O₅ system, the starting components CsPO₃ (3.0 g), MgO (0.113 g) and Bi₂O₃ (0.652 g) were finely ground and melted in a platinum crucible at 1273 K. The melt was kept at this temperature over 2 h to reach homogeneity and then cooled at a rate of 30 K h^-1 to 993 K. After the melt was cooled to room temperature and treated with a small amount of deionized water, colorless needle-shaped crystals were isolated. X-ray powder diffraction showed that CsMgPO₄ is the only crystalline product.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis CCD (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: WinGX (Farrugia, 1999) and enCIFer (Allen et al., 2004).

Figures top

	Fig. 1. View of CsMgPO₄ with displacement ellipsoids at the 50% probability level.
	Fig. 2. Formation of hexagonal channels along a and b directions in CsMgPO₄ (PO₄, pink; MgO₄, yellow; Cs, blue).

Caesium magnesium orthophosphate top

Crystal data top

CsMgPO₄	F(000) = 456
M_r = 252.19	D_x = 3.516 Mg m⁻³
Orthorhombic, Pnma	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2n	Cell parameters from 8753 reflections
a = 8.9327 (2) Å	θ = 3.1–35.0°
b = 5.5277 (2) Å	µ = 8.13 mm⁻¹
c = 9.6487 (3) Å	T = 293 K
V = 476.43 (3) Å³	Prism, colorless
Z = 4	0.12 × 0.10 × 0.08 mm

Data collection top

Oxford Diffraction Xcalibur-3 diffractometer	1137 independent reflections
Radiation source: fine-focus sealed tube	874 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.027
ϕ and ω scans	θ_max = 35.0°, θ_min = 3.1°
Absorption correction: multi-scan (Blessing, 1995)	h = −14→14
T_min = 0.413, T_max = 0.503	k = −8→8
8753 measured reflections	l = −15→15

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)] = 0.021	w = 1/[σ²(F_o²) + (0.0265P)²] where P = (F_o² + 2F_c²)/3
wR(F²) = 0.047	(Δ/σ)_max = 0.018
S = 1.00	Δρ_max = 1.23 e Å⁻³
1137 reflections	Δρ_min = −1.02 e Å⁻³
41 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008)
0 restraints	Extinction coefficient: 0.0211 (4)

Crystal data top

CsMgPO₄	V = 476.43 (3) Å³
M_r = 252.19	Z = 4
Orthorhombic, Pnma	Mo Kα radiation
a = 8.9327 (2) Å	µ = 8.13 mm⁻¹
b = 5.5277 (2) Å	T = 293 K
c = 9.6487 (3) Å	0.12 × 0.10 × 0.08 mm

Data collection top

Oxford Diffraction Xcalibur-3 diffractometer	1137 independent reflections
Absorption correction: multi-scan (Blessing, 1995)	874 reflections with I > 2σ(I)
T_min = 0.413, T_max = 0.503	R_int = 0.027
8753 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.021	41 parameters
wR(F²) = 0.047	0 restraints
S = 1.00	Δρ_max = 1.23 e Å⁻³
1137 reflections	Δρ_min = −1.02 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
Cs1	0.497176 (11)	0.25	0.703332 (10)	0.02472 (2)
Mg1	0.32166 (5)	0.25	0.08109 (5)	0.01434 (11)
P1	0.20302 (4)	0.25	0.41474 (4)	0.01345 (7)
O1	0.26034 (19)	0.25	0.26799 (13)	0.0590 (6)
O2	0.26291 (11)	0.02604 (13)	0.48850 (9)	0.0328 (2)
O3	0.03356 (14)	0.25	0.41501 (19)	0.0345 (4)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cs1	0.02161 (4)	0.02632 (5)	0.02623 (4)	0	−0.00031 (4)	0
Mg1	0.01301 (19)	0.0133 (2)	0.0168 (2)	0	0.00166 (17)	0
P1	0.01272 (13)	0.01259 (14)	0.01505 (14)	0	0.00207 (12)	0
O1	0.0594 (11)	0.1014 (17)	0.0162 (7)	0	0.0121 (7)	0
O2	0.0239 (4)	0.0190 (4)	0.0555 (6)	−0.0002 (3)	−0.0016 (4)	0.0156 (4)
O3	0.0121 (4)	0.0286 (6)	0.0629 (10)	0	−0.0003 (6)	0

Geometric parameters (Å, º) top

Cs1—O2	3.1951 (9)	Mg1—Cs1^xiii	4.1402 (4)
Cs1—O2ⁱ	3.1951 (9)	P1—O1	1.5056 (13)
Cs1—O2ⁱⁱ	3.2166 (9)	P1—O3	1.5138 (13)
Cs1—O2ⁱⁱⁱ	3.2166 (9)	P1—O2ⁱ	1.5249 (8)
Cs1—O3^iv	3.4476 (11)	P1—O2	1.5249 (8)
Cs1—O3^v	3.4476 (11)	P1—Cs1^ix	3.8727 (3)
Cs1—O1^vi	3.5224 (11)	P1—Cs1^xiii	3.8727 (3)
Cs1—O1ⁱⁱ	3.5224 (11)	P1—Cs1^vi	4.0136 (3)
Cs1—O1^v	3.6496 (11)	P1—Cs1ⁱⁱ	4.0136 (3)
Cs1—O1^iv	3.6496 (11)	P1—Cs1^xiv	4.1184 (4)
Cs1—O3^vii	3.6968 (18)	O1—Cs1^vi	3.5224 (11)
Cs1—Mg1^vi	3.8189 (4)	O1—Cs1ⁱⁱ	3.5224 (11)
Mg1—O1	1.8847 (13)	O1—Cs1^ix	3.6496 (11)
Mg1—O3^viii	1.8932 (13)	O1—Cs1^xiii	3.6496 (11)
Mg1—O2^ix	1.9228 (8)	O2—Mg1^v	1.9228 (8)
Mg1—O2^x	1.9228 (8)	O2—Cs1ⁱⁱ	3.2166 (9)
Mg1—Cs1^vi	3.8189 (4)	O3—Mg1^xii	1.8932 (13)
Mg1—Cs1ⁱⁱ	3.8189 (4)	O3—Cs1^ix	3.4476 (11)
Mg1—Cs1^xi	3.9678 (5)	O3—Cs1^xiii	3.4476 (11)
Mg1—Cs1^xii	3.9916 (5)	O3—Cs1^xiv	3.6968 (18)
Mg1—Cs1^ix	4.1402 (4)

O2—Cs1—O2ⁱ	45.59 (3)	O1—Mg1—Cs1^ix	61.80 (3)
O2—Cs1—O2ⁱⁱ	83.06 (3)	O3^viii—Mg1—Cs1^ix	133.01 (2)
O2ⁱ—Cs1—O2ⁱⁱ	104.291 (19)	O2^ix—Mg1—Cs1^ix	48.11 (3)
O2—Cs1—O2ⁱⁱⁱ	104.291 (19)	O2^x—Mg1—Cs1^ix	113.07 (3)
O2ⁱ—Cs1—O2ⁱⁱⁱ	83.06 (3)	Cs1^vi—Mg1—Cs1^ix	128.277 (13)
O2ⁱⁱ—Cs1—O2ⁱⁱⁱ	56.64 (3)	Cs1ⁱⁱ—Mg1—Cs1^ix	69.709 (5)
O2—Cs1—O3^iv	130.00 (3)	Cs1^xi—Mg1—Cs1^ix	122.243 (9)
O2ⁱ—Cs1—O3^iv	91.24 (3)	Cs1^xii—Mg1—Cs1^ix	72.323 (7)
O2ⁱⁱ—Cs1—O3^iv	140.73 (3)	O1—Mg1—Cs1^xiii	61.80 (3)
O2ⁱⁱⁱ—Cs1—O3^iv	90.78 (3)	O3^viii—Mg1—Cs1^xiii	133.01 (2)
O2—Cs1—O3^v	91.24 (3)	O2^ix—Mg1—Cs1^xiii	113.07 (3)
O2ⁱ—Cs1—O3^v	130.00 (3)	O2^x—Mg1—Cs1^xiii	48.11 (3)
O2ⁱⁱ—Cs1—O3^v	90.78 (3)	Cs1^vi—Mg1—Cs1^xiii	69.709 (5)
O2ⁱⁱⁱ—Cs1—O3^v	140.73 (3)	Cs1ⁱⁱ—Mg1—Cs1^xiii	128.277 (14)
O3^iv—Cs1—O3^v	106.58 (5)	Cs1^xi—Mg1—Cs1^xiii	122.243 (9)
O2—Cs1—O1^vi	139.27 (2)	Cs1^xii—Mg1—Cs1^xiii	72.323 (7)
O2ⁱ—Cs1—O1^vi	98.61 (3)	Cs1^ix—Mg1—Cs1^xiii	83.758 (9)
O2ⁱⁱ—Cs1—O1^vi	90.44 (3)	O1—P1—O3	109.98 (10)
O2ⁱⁱⁱ—Cs1—O1^vi	42.55 (2)	O1—P1—O2ⁱ	108.64 (5)
O3^iv—Cs1—O1^vi	51.20 (3)	O3—P1—O2ⁱ	110.49 (5)
O3^v—Cs1—O1^vi	129.16 (3)	O1—P1—O2	108.64 (5)
O2—Cs1—O1ⁱⁱ	98.61 (3)	O3—P1—O2	110.49 (5)
O2ⁱ—Cs1—O1ⁱⁱ	139.27 (2)	O2ⁱ—P1—O2	108.56 (7)
O2ⁱⁱ—Cs1—O1ⁱⁱ	42.55 (2)	O1—P1—Cs1	116.78 (7)
O2ⁱⁱⁱ—Cs1—O1ⁱⁱ	90.44 (3)	O3—P1—Cs1	133.24 (7)
O3^iv—Cs1—O1ⁱⁱ	129.16 (3)	O2ⁱ—P1—Cs1	54.54 (3)
O3^v—Cs1—O1ⁱⁱ	51.20 (3)	O2—P1—Cs1	54.54 (3)
O1^vi—Cs1—O1ⁱⁱ	103.38 (4)	O1—P1—Cs1^ix	70.23 (4)
O2—Cs1—O1^v	53.46 (2)	O3—P1—Cs1^ix	62.56 (4)
O2ⁱ—Cs1—O1^v	89.52 (3)	O2ⁱ—P1—Cs1^ix	170.83 (4)
O2ⁱⁱ—Cs1—O1^v	99.15 (2)	O2—P1—Cs1^ix	80.12 (3)
O2ⁱⁱⁱ—Cs1—O1^v	151.35 (2)	Cs1—P1—Cs1^ix	134.428 (4)
O3^iv—Cs1—O1^v	117.11 (3)	O1—P1—Cs1^xiii	70.23 (4)
O3^v—Cs1—O1^v	40.66 (3)	O3—P1—Cs1^xiii	62.56 (4)
O1^vi—Cs1—O1^v	165.554 (5)	O2ⁱ—P1—Cs1^xiii	80.12 (3)
O1ⁱⁱ—Cs1—O1^v	77.288 (3)	O2—P1—Cs1^xiii	170.83 (4)
O2—Cs1—O1^iv	89.52 (3)	Cs1—P1—Cs1^xiii	134.428 (4)
O2ⁱ—Cs1—O1^iv	53.46 (2)	Cs1^ix—P1—Cs1^xiii	91.069 (8)
O2ⁱⁱ—Cs1—O1^iv	151.35 (2)	O1—P1—Cs1^vi	60.41 (4)
O2ⁱⁱⁱ—Cs1—O1^iv	99.15 (2)	O3—P1—Cs1^vi	131.89 (3)
O3^iv—Cs1—O1^iv	40.66 (3)	O2ⁱ—P1—Cs1^vi	48.65 (4)
O3^v—Cs1—O1^iv	117.11 (3)	O2—P1—Cs1^vi	117.22 (4)
O1^vi—Cs1—O1^iv	77.288 (3)	Cs1—P1—Cs1^vi	75.434 (6)
O1ⁱⁱ—Cs1—O1^iv	165.554 (5)	Cs1^ix—P1—Cs1^vi	130.546 (10)
O1^v—Cs1—O1^iv	98.45 (4)	Cs1^xiii—P1—Cs1^vi	70.558 (4)
O2—Cs1—O3^vii	134.74 (2)	O1—P1—Cs1ⁱⁱ	60.41 (4)
O2ⁱ—Cs1—O3^vii	134.74 (2)	O3—P1—Cs1ⁱⁱ	131.89 (3)
O2ⁱⁱ—Cs1—O3^vii	120.97 (2)	O2ⁱ—P1—Cs1ⁱⁱ	117.22 (4)
O2ⁱⁱⁱ—Cs1—O3^vii	120.97 (2)	O2—P1—Cs1ⁱⁱ	48.65 (4)
O3^iv—Cs1—O3^vii	54.33 (3)	Cs1—P1—Cs1ⁱⁱ	75.434 (6)
O3^v—Cs1—O3^vii	54.33 (3)	Cs1^ix—P1—Cs1ⁱⁱ	70.558 (4)
O1^vi—Cs1—O3^vii	82.40 (2)	Cs1^xiii—P1—Cs1ⁱⁱ	130.546 (10)
O1ⁱⁱ—Cs1—O3^vii	82.40 (2)	Cs1^vi—P1—Cs1ⁱⁱ	87.043 (8)
O1^v—Cs1—O3^vii	83.40 (2)	O1—P1—Cs1^xiv	173.36 (7)
O1^iv—Cs1—O3^vii	83.40 (2)	O3—P1—Cs1^xiv	63.38 (7)
O2—Cs1—Mg1^vi	155.689 (15)	O2ⁱ—P1—Cs1^xiv	74.87 (4)
O2ⁱ—Cs1—Mg1^vi	110.517 (14)	O2—P1—Cs1^xiv	74.87 (4)
O2ⁱⁱ—Cs1—Mg1^vi	111.987 (18)	Cs1—P1—Cs1^xiv	69.857 (6)
O2ⁱⁱⁱ—Cs1—Mg1^vi	71.807 (16)	Cs1^ix—P1—Cs1^xiv	105.375 (7)
O3^iv—Cs1—Mg1^vi	29.64 (2)	Cs1^xiii—P1—Cs1^xiv	105.375 (7)
O3^v—Cs1—Mg1^vi	106.93 (3)	Cs1^vi—P1—Cs1^xiv	123.498 (7)
O1^vi—Cs1—Mg1^vi	29.40 (2)	Cs1ⁱⁱ—P1—Cs1^xiv	123.498 (7)
O1ⁱⁱ—Cs1—Mg1^vi	105.34 (2)	P1—O1—Mg1	177.02 (12)
O1^v—Cs1—Mg1^vi	136.22 (2)	P1—O1—Cs1^vi	97.77 (4)
O1^iv—Cs1—Mg1^vi	68.03 (2)	Mg1—O1—Cs1^vi	84.06 (4)
O3^vii—Cs1—Mg1^vi	54.563 (11)	P1—O1—Cs1ⁱⁱ	97.77 (4)
O1—Mg1—O3^viii	105.76 (8)	Mg1—O1—Cs1ⁱⁱ	84.06 (4)
O1—Mg1—O2^ix	109.29 (4)	Cs1^vi—O1—Cs1ⁱⁱ	103.38 (4)
O3^viii—Mg1—O2^ix	113.71 (4)	P1—O1—Cs1^ix	86.93 (5)
O1—Mg1—O2^x	109.29 (4)	Mg1—O1—Cs1^ix	91.12 (4)
O3^viii—Mg1—O2^x	113.71 (4)	Cs1^vi—O1—Cs1^ix	174.41 (4)
O2^ix—Mg1—O2^x	105.04 (6)	Cs1ⁱⁱ—O1—Cs1^ix	78.860 (3)
O1—Mg1—Cs1^vi	66.55 (3)	P1—O1—Cs1^xiii	86.93 (5)
O3^viii—Mg1—Cs1^vi	64.25 (3)	Mg1—O1—Cs1^xiii	91.12 (4)
O2^ix—Mg1—Cs1^vi	173.66 (3)	Cs1^vi—O1—Cs1^xiii	78.860 (3)
O2^x—Mg1—Cs1^vi	81.10 (3)	Cs1ⁱⁱ—O1—Cs1^xiii	174.41 (4)
O1—Mg1—Cs1ⁱⁱ	66.55 (3)	Cs1^ix—O1—Cs1^xiii	98.45 (4)
O3^viii—Mg1—Cs1ⁱⁱ	64.25 (3)	P1—O2—Mg1^v	136.32 (7)
O2^ix—Mg1—Cs1ⁱⁱ	81.10 (3)	P1—O2—Cs1	102.59 (4)
O2^x—Mg1—Cs1ⁱⁱ	173.66 (3)	Mg1^v—O2—Cs1	105.27 (4)
Cs1^vi—Mg1—Cs1ⁱⁱ	92.725 (11)	P1—O2—Cs1ⁱⁱ	110.51 (4)
O1—Mg1—Cs1^xi	173.62 (6)	Mg1^v—O2—Cs1ⁱⁱ	98.78 (3)
O3^viii—Mg1—Cs1^xi	67.86 (6)	Cs1—O2—Cs1ⁱⁱ	96.94 (3)
O2^ix—Mg1—Cs1^xi	74.24 (3)	P1—O3—Mg1^xii	178.96 (13)
O2^x—Mg1—Cs1^xi	74.24 (3)	P1—O3—Cs1^ix	94.51 (5)
Cs1^vi—Mg1—Cs1^xi	109.444 (9)	Mg1^xii—O3—Cs1^ix	86.11 (4)
Cs1ⁱⁱ—Mg1—Cs1^xi	109.444 (9)	P1—O3—Cs1^xiii	94.51 (5)
O1—Mg1—Cs1^xii	116.54 (5)	Mg1^xii—O3—Cs1^xiii	86.11 (4)
O3^viii—Mg1—Cs1^xii	137.70 (6)	Cs1^ix—O3—Cs1^xiii	106.58 (5)
O2^ix—Mg1—Cs1^xii	52.79 (3)	P1—O3—Cs1^xiv	95.14 (8)
O2^x—Mg1—Cs1^xii	52.79 (3)	Mg1^xii—O3—Cs1^xiv	83.82 (6)
Cs1^vi—Mg1—Cs1^xii	133.015 (6)	Cs1^ix—O3—Cs1^xiv	125.67 (3)
Cs1ⁱⁱ—Mg1—Cs1^xii	133.015 (6)	Cs1^xiii—O3—Cs1^xiv	125.67 (3)
Cs1^xi—Mg1—Cs1^xii	69.840 (9)

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

Experimental details

Crystal data
Chemical formula	CsMgPO₄
M_r	252.19
Crystal system, space group	Orthorhombic, Pnma
Temperature (K)	293
a, b, c (Å)	8.9327 (2), 5.5277 (2), 9.6487 (3)
V (Å³)	476.43 (3)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	8.13
Crystal size (mm)	0.12 × 0.10 × 0.08

Data collection
Diffractometer	Oxford Diffraction Xcalibur-3 diffractometer
Absorption correction	Multi-scan (Blessing, 1995)
T_min, T_max	0.413, 0.503
No. of measured, independent and observed [I > 2σ(I)] reflections	8753, 1137, 874
R_int	0.027
(sin θ/λ)_max (Å⁻¹)	0.807

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.021, 0.047, 1.00
No. of reflections	1137
No. of parameters	41
Δρ_max, Δρ_min (e Å⁻³)	1.23, −1.02

Computer programs: CrysAlis CCD (Oxford Diffraction, 2006), CrysAlis RED (Oxford Diffraction, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1999), WinGX (Farrugia, 1999) and enCIFer (Allen et al., 2004).

Selected bond lengths (Å) top

Cs1—O2	3.1951 (9)	Mg1—O1	1.8847 (13)
Cs1—O2ⁱ	3.2166 (9)	Mg1—O3^iv	1.8932 (13)
Cs1—O3ⁱⁱ	3.4476 (11)	Mg1—O2^v	1.9228 (8)
Cs1—O1ⁱ	3.5224 (11)	P1—O1	1.5056 (13)
Cs1—O1ⁱⁱ	3.6496 (11)	P1—O3	1.5138 (13)
Cs1—O3ⁱⁱⁱ	3.6968 (18)	P1—O2	1.5249 (8)

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

Acknowledgements

The authors acknowledge the ICDD for financial support (grant No. 03–02).

References

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