Silver trimagnesium phosphate bis­(hydrogenphosphate), AgMg3(PO4)(HPO4)2, with an alluaudite-like structure

Assani, A.; Saadi, M.; Zriouil, M.; El Ammari, L.

doi:10.1107/S1600536810053304

inorganic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 67| Part 1| January 2011| Page i5

https://doi.org/10.1107/S1600536810053304

Open

access

Silver trimagnesium phosphate bis(hydrogenphosphate), AgMg₃(PO₄)(HPO₄)₂, with an alluaudite-like structure

Abderrazzak Assani,^a ^* Mohamed Saadi,^a Mohammed Zriouil ^a and Lahcen El Ammari ^a

^aLaboratoire de Chimie du Solide Appliquée, Faculté des Sciences, Université Mohammed V-Agdal, Avenue Ibn Battouta, BP 1014, Rabat, Morocco
^*Correspondence e-mail: abder_assani@yahoo.fr

(Received 29 November 2010; accepted 19 December 2010; online 24 December 2010)

The title compound, AgMg₃(PO₄)(HPO₄)₂, which has been synthesized by the hydrothermal method, has an alluaudite-like structure which is formed by edge-sharing MgO₆ octahedra (one of which has symmetry 2), resulting in chains linked together by phosphate groups and hydrogen bonds. The three-dimensional framework leads to two different channels along the c axis, one of which is occupied by Ag⁺ ions with a square-planar coordination. The Ag⁺ ions are disordered over two sites in a 0.89 (3):0.11 (3) ratio. The OH groups, which point into the other type of channel, are involved in strong O—H⋯O hydrogen bonds. The title compound is isotypic with the compounds AM₃H₂(XO₄)(HXO₄)₂ (A = Na or Ag, M = Mn, Co or Ni, and X = P or As) of the alluaudite structure type.

Related literature

For applications of related compounds, see: Kacimi et al. (2005 ); Korzenski et al. (1998 ); Trad et al. (2010 ). For compounds with the same structure type, see: Moore (1971 ); Hatert (2008 ); Hatert et al. (2000 ); Assani et al. (2010 ); Guesmi & Driss (2002 ); Ben Smail & Jouini (2002 ); Stock & Bein (2003 ); Leroux et al. (1995 ).

Experimental

Crystal data

AgMg₃(PO₄)(HPO₄)₂
M_r = 467.73
Monoclinic, C 2/c
a = 11.9126 (5) Å
b = 12.1197 (6) Å
c = 6.4780 (3) Å
β = 113.812 (2)°
V = 855.66 (7) Å³
Z = 4
Mo Kα radiation
μ = 3.21 mm⁻¹
T = 296 K
0.31 × 0.16 × 0.12 mm

Data collection

Bruker X8 APEX diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.545, T_max = 0.680
10680 measured reflections
2330 independent reflections
1998 reflections with I > 2σ(I)
R_int = 0.034

Refinement

R[F² > 2σ(F²)] = 0.026
wR(F²) = 0.075
S = 1.08
2330 reflections
91 parameters
H-atom parameters constrained
Δρ_max = 0.63 e Å⁻³
Δρ_min = −1.28 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O6—H6⋯O1ⁱ	0.86	1.68	2.5266 (17)	168
Symmetry code: (i) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ) and DIAMOND (Brandenburg, 2006 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810053304/fj2371sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810053304/fj2371Isup2.hkl

checkCIF report

Comment top

Compounds belonging to the large structural family of alluaudite derivatives (Moore (1971); Hatert et al. (2000)) have been of continuing interest due to their structural properties, such as their open-framework architecture and their physical properties. Accordingly, the alluaudite structure exhibit an appropriate frameworks for a variety of applications, such as corrosion inhibition, passivation of metal surfaces, and catalysis (Hatert (2008); Korzenski et al. (1998); Kacimi et al. (2005)).

In addition, the accommodation of the monovalent cations in the one-dimensional channels of the alluaudite-like structures is strongly required for conductivity properties and have offered a great field of application as positive electrode in the lithium and sodium batteries (Trad et al. 2010)

By means of the powerful hydrothermal technique, our attempts to synthesize new monovalent divalent cations phosphate with alluaudite –like structure have successfully allowed to obtain a new silver magnesium phosphate phase. The present paper aims to report detailed hydrothermal synthesis and structural characterization of the title compound.

The structure is built up from MgO₆ octahedra, PO₄ and PO₃(OH) tetrahedra, sharing corners and edges to form a three-dimensional framework as schown in Fig.1 and Fig.2. The three-dimensional network delimits two types of hexagonal channels which accommodate Ag+ cations and OH groups (see Fig.2). In the channels, each silver atoms is surrounded by four O atoms with Ag–O bond length varies between 2.3621 and 2.5150 Å. The same Ag⁺coordination sphere is observed in γ-AgZnPO₄ (Assani et al. (2010)). Moreover the OH groups, pointing into one type of channel, are involved in strong hydrogen bonds. The silver trimagnesium phosphate bis-(hydrogenphosphate): AgMg₃(PO₄)(HPO₄)₂, is isostructural with the compounds AM₃H₂(XO₄)₃ (A = Na or Ag, M = Mn, Co or Ni, and X = P or As) of the alluaudite structure type (Guesmi & Driss (2002); Ben Smail & Jouini (2002); Stock & Bein (2003).

Related literature top

For applications of related compounds, see: Kacimi et al. (2005); Korzenski et al. (1998); Trad et al. (2010). For compounds with the same structure type, see: Moore (1971); Hatert (2008); Hatert et al. (2000); Assani et al. (2010); Guesmi & Driss (2002); Ben Smail & Jouini (2002); Stock & Bein (2003); Leroux et al. (1995).

Experimental top

The crystals of the title compound has been hydrothermally synthesized starting from a mixture of magnesium oxide (0,0605 g), silver nitrate (0,1699 g), 85 wt % phosphoric acid (0,10 ml), and 12 ml of water. The hydrothermal synthesis was carried out in 23 ml Teflon-lined autoclave under autogeneous pressure at 468 K during 24 h. The product was filtered off, washed with deionized water and air dried. The reaction product consists yellow powder besides a colorless parallelepipedic crystals of the title compound.

Structure description top

For applications of related compounds, see: Kacimi et al. (2005); Korzenski et al. (1998); Trad et al. (2010). For compounds with the same structure type, see: Moore (1971); Hatert (2008); Hatert et al. (2000); Assani et al. (2010); Guesmi & Driss (2002); Ben Smail & Jouini (2002); Stock & Bein (2003); Leroux et al. (1995).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

Fig. 1. Partial plot of AgMg₃(PO₄)(HPO₄)₂ crystal structure. Displacement ellipsoids are drawn at the 50% probability level. Only the major component of the disordered silver atom is shown. Symmetry codes: (i) -x + 1/2, y - 1/2, -z + 1/2; (ii) x + 1/2, y - 1/2, z + 1; (iii) x + 1/2, -y + 1/2, z + 1/2; (iv) -x + 1/2, -y + 1/2, -z + 1; (v) -x + 1, y, -z + 3/2; (vi) -x + 1, -y, -z + 1; (vii) -x + 1, -y, -z + 2; (viii) x + 1/2, -y + 1/2, z - 1/2; (ix) -x + 1/2, -y + 1/2, -z; (x) -x + 1, y, -z + 1/2; (xi) -x, y, -z + 1/2; (xii) -x + 1/2, y + 1/2, -z + 1/2; (xiii) x - 1/2, y + 1/2, z - 1.

Fig. 2. A three-dimensional polyhedral view of the crystal structure of the AgMg₃(PO₄)(HPO₄)₂, showing the channels running along the c direction,at 0,0,z and 1/2,0,z. Hydrogen bonds are indicated by dashed lines.

Silver trimagnesium phosphate bis(hydrogenphosphate) top

Crystal data top

AgMg₃(PO₄)(HPO₄)₂	F(000) = 904
M_r = 467.73	D_x = 3.631 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 2330 reflections
a = 11.9126 (5) Å	θ = 2.5–38.0°
b = 12.1197 (6) Å	µ = 3.21 mm⁻¹
c = 6.4780 (3) Å	T = 296 K
β = 113.812 (2)°	Prism, colourless
V = 855.66 (7) Å³	0.31 × 0.16 × 0.12 mm
Z = 4

Data collection top

Bruker X8 APEX diffractometer	2330 independent reflections
Radiation source: fine-focus sealed tube	1998 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.034
φ and ω scans	θ_max = 38.0°, θ_min = 2.5°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −20→20
T_min = 0.545, T_max = 0.680	k = −20→20
10680 measured reflections	l = −11→10

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.026	H-atom parameters constrained
wR(F²) = 0.075	w = 1/[σ²(F_o²) + (0.0323P)² + 1.8049P] where P = (F_o² + 2F_c²)/3
S = 1.08	(Δ/σ)_max = 0.002
2330 reflections	Δρ_max = 0.63 e Å⁻³
91 parameters	Δρ_min = −1.28 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0013 (3)

Crystal data top

AgMg₃(PO₄)(HPO₄)₂	V = 855.66 (7) Å³
M_r = 467.73	Z = 4
Monoclinic, C2/c	Mo Kα radiation
a = 11.9126 (5) Å	µ = 3.21 mm⁻¹
b = 12.1197 (6) Å	T = 296 K
c = 6.4780 (3) Å	0.31 × 0.16 × 0.12 mm
β = 113.812 (2)°

Data collection top

Bruker X8 APEX diffractometer	2330 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	1998 reflections with I > 2σ(I)
T_min = 0.545, T_max = 0.680	R_int = 0.034
10680 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.026	0 restraints
wR(F²) = 0.075	H-atom parameters constrained
S = 1.08	Δρ_max = 0.63 e Å⁻³
2330 reflections	Δρ_min = −1.28 e Å⁻³
91 parameters

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	Occ. (<1)
Ag1A	0.5000	0.0261 (4)	0.7500	0.0192 (3)	0.89 (3)
Ag1B	0.5000	0.0047 (18)	0.7500	0.0192 (3)	0.11 (3)
Mg1	0.5000	0.27737 (7)	0.2500	0.00765 (14)
Mg2	0.28999 (6)	0.16182 (5)	0.37691 (10)	0.00621 (10)
P1	0.0000	0.18606 (5)	0.2500	0.00545 (10)
P2	0.22298 (4)	0.38713 (3)	0.11567 (7)	0.00508 (8)
O1	0.10721 (11)	0.10964 (10)	0.2643 (2)	0.00793 (19)
O2	0.03617 (10)	0.25753 (10)	0.46302 (18)	0.00686 (19)
O3	0.15657 (11)	0.32826 (10)	−0.11097 (19)	0.00676 (19)
O4	0.21721 (11)	0.31920 (10)	0.30907 (18)	0.00623 (18)
O5	0.16491 (11)	0.50095 (10)	0.1050 (2)	0.00777 (19)
O6	0.36178 (11)	0.40491 (10)	0.1603 (2)	0.00812 (19)
H6	0.3747	0.4749	0.1705	0.012*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Ag1A	0.00987 (9)	0.0318 (8)	0.01280 (10)	0.000	0.00135 (7)	0.000
Ag1B	0.00987 (9)	0.0318 (8)	0.01280 (10)	0.000	0.00135 (7)	0.000
Mg1	0.0087 (3)	0.0072 (3)	0.0080 (3)	0.000	0.0044 (3)	0.000
Mg2	0.0076 (2)	0.0049 (2)	0.0068 (2)	0.00050 (17)	0.00358 (18)	0.00038 (17)
P1	0.0062 (2)	0.0052 (2)	0.0043 (2)	0.000	0.00141 (17)	0.000
P2	0.00704 (15)	0.00373 (16)	0.00436 (15)	0.00011 (11)	0.00219 (12)	0.00006 (11)
O1	0.0057 (4)	0.0061 (5)	0.0116 (5)	0.0009 (3)	0.0032 (4)	−0.0004 (4)
O2	0.0064 (4)	0.0087 (5)	0.0049 (4)	−0.0008 (3)	0.0017 (3)	−0.0018 (3)
O3	0.0086 (5)	0.0069 (5)	0.0045 (4)	−0.0009 (3)	0.0023 (3)	−0.0011 (3)
O4	0.0083 (4)	0.0058 (4)	0.0048 (4)	0.0001 (3)	0.0029 (3)	0.0013 (3)
O5	0.0091 (5)	0.0045 (4)	0.0096 (5)	0.0012 (3)	0.0036 (4)	−0.0004 (3)
O6	0.0067 (4)	0.0056 (5)	0.0123 (5)	−0.0007 (3)	0.0042 (4)	−0.0001 (4)

Geometric parameters (Å, º) top

Ag1A—O5ⁱ	2.3649 (14)	Mg2—O5ⁱ	2.0132 (13)
Ag1A—O5ⁱⁱ	2.3649 (14)	Mg2—O3^ix	2.0672 (13)
Ag1A—O5ⁱⁱⁱ	2.5177 (14)	Mg2—O4	2.0677 (13)
Ag1A—O5^iv	2.5177 (14)	Mg2—O4^iv	2.0831 (13)
Ag1A—Mg2	3.150 (3)	Mg2—O1	2.0954 (13)
Ag1A—Mg2^v	3.150 (3)	Mg2—O2^iv	2.1414 (13)
Ag1A—Ag1B^vi	3.260 (3)	Mg2—Mg2^iv	3.0408 (12)
Ag1A—Ag1B^vii	3.260 (3)	Mg2—P2	3.1411 (7)
Ag1A—Ag1A^vi	3.3001 (19)	Mg2—P2^ix	3.1874 (7)
Ag1A—Ag1A^vii	3.3001 (19)	P1—O2	1.5363 (12)
Ag1B—O5ⁱ	2.3457 (13)	P1—O2^xi	1.5363 (12)
Ag1B—O5ⁱⁱ	2.3457 (13)	P1—O1	1.5497 (12)
Ag1B—O5ⁱⁱⁱ	2.4972 (14)	P1—O1^xi	1.5497 (12)
Ag1B—O5^iv	2.4972 (14)	P2—O4	1.5237 (12)
Ag1B—Ag1B^vi	3.2410 (15)	P2—O5	1.5322 (13)
Ag1B—Ag1B^vii	3.2410 (15)	P2—O3	1.5337 (12)
Ag1B—Ag1A^vi	3.260 (3)	P2—O6	1.5742 (13)
Ag1B—Ag1A^vii	3.260 (3)	P2—Mg2^ix	3.1874 (7)
Ag1B—Mg2	3.293 (12)	O2—Mg1^iv	2.1136 (12)
Ag1B—Mg2^v	3.293 (12)	O2—Mg2^iv	2.1414 (13)
Ag1B—Mg1^vi	3.42 (2)	O3—Mg2^ix	2.0672 (13)
Mg1—O2^viii	2.1136 (12)	O3—Mg1^ix	2.1384 (13)
Mg1—O2^iv	2.1136 (12)	O4—Mg2^iv	2.0831 (13)
Mg1—O3^ix	2.1383 (13)	O5—Mg2^xii	2.0133 (13)
Mg1—O3ⁱⁱⁱ	2.1383 (13)	O5—Ag1B^xiii	2.3457 (13)
Mg1—O6	2.1600 (14)	O5—Ag1A^xiii	2.3649 (14)
Mg1—O6^x	2.1601 (14)	O5—Ag1B^iv	2.4972 (14)
Mg1—Mg2^x	3.2491 (7)	O5—Ag1A^iv	2.5177 (14)
Mg1—Mg2	3.2492 (7)	O6—H6	0.8600
Mg1—Ag1B^vi	3.42 (2)

O5ⁱ—Ag1A—O5ⁱⁱ	165.2 (2)	O6^x—Mg1—Mg2	145.25 (4)
O5ⁱ—Ag1A—O5ⁱⁱⁱ	95.01 (5)	Mg2^x—Mg1—Mg2	128.94 (3)
O5ⁱⁱ—Ag1A—O5ⁱⁱⁱ	83.06 (5)	O2^viii—Mg1—Ag1B^vi	78.46 (4)
O5ⁱ—Ag1A—O5^iv	83.06 (5)	O2^iv—Mg1—Ag1B^vi	78.46 (4)
O5ⁱⁱ—Ag1A—O5^iv	95.01 (5)	O3^ix—Mg1—Ag1B^vi	53.22 (4)
O5ⁱⁱⁱ—Ag1A—O5^iv	165.0 (2)	O3ⁱⁱⁱ—Mg1—Ag1B^vi	53.22 (4)
O5ⁱ—Ag1A—Mg2	39.70 (5)	O6—Mg1—Ag1B^vi	135.69 (4)
O5ⁱⁱ—Ag1A—Mg2	154.68 (19)	O6^x—Mg1—Ag1B^vi	135.70 (4)
O5ⁱⁱⁱ—Ag1A—Mg2	106.22 (6)	Mg2^x—Mg1—Ag1B^vi	64.468 (17)
O5^iv—Ag1A—Mg2	81.75 (5)	Mg2—Mg1—Ag1B^vi	64.467 (17)
O5ⁱ—Ag1A—Mg2^v	154.68 (19)	O5ⁱ—Mg2—O3^ix	86.56 (5)
O5ⁱⁱ—Ag1A—Mg2^v	39.70 (5)	O5ⁱ—Mg2—O4	170.04 (6)
O5ⁱⁱⁱ—Ag1A—Mg2^v	81.75 (5)	O3^ix—Mg2—O4	90.74 (5)
O5^iv—Ag1A—Mg2^v	106.22 (6)	O5ⁱ—Mg2—O4^iv	99.52 (5)
Mg2—Ag1A—Mg2^v	117.04 (15)	O3^ix—Mg2—O4^iv	162.82 (6)
O5ⁱ—Ag1A—Ag1B^vi	49.64 (5)	O4—Mg2—O4^iv	85.79 (5)
O5ⁱⁱ—Ag1A—Ag1B^vi	128.18 (15)	O5ⁱ—Mg2—O1	86.75 (5)
O5ⁱⁱⁱ—Ag1A—Ag1B^vi	45.70 (5)	O3^ix—Mg2—O1	110.73 (5)
O5^iv—Ag1A—Ag1B^vi	131.97 (16)	O4—Mg2—O1	85.23 (5)
Mg2—Ag1A—Ag1B^vi	67.4 (3)	O4^iv—Mg2—O1	85.78 (5)
Mg2^v—Ag1A—Ag1B^vi	120.2 (3)	O5ⁱ—Mg2—O2^iv	103.34 (5)
O5ⁱ—Ag1A—Ag1B^vii	128.18 (15)	O3^ix—Mg2—O2^iv	79.28 (5)
O5ⁱⁱ—Ag1A—Ag1B^vii	49.64 (5)	O4—Mg2—O2^iv	85.55 (5)
O5ⁱⁱⁱ—Ag1A—Ag1B^vii	131.97 (16)	O4^iv—Mg2—O2^iv	83.67 (5)
O5^iv—Ag1A—Ag1B^vii	45.70 (5)	O1—Mg2—O2^iv	166.46 (6)
Mg2—Ag1A—Ag1B^vii	120.2 (3)	O5ⁱ—Mg2—Mg2^iv	141.54 (5)
Mg2^v—Ag1A—Ag1B^vii	67.4 (3)	O3^ix—Mg2—Mg2^iv	131.55 (5)
Ag1B^vi—Ag1A—Ag1B^vii	166.9 (9)	O4—Mg2—Mg2^iv	43.09 (3)
O5ⁱ—Ag1A—Ag1A^vi	49.46 (4)	O4^iv—Mg2—Mg2^iv	42.70 (3)
O5ⁱⁱ—Ag1A—Ag1A^vi	126.91 (10)	O1—Mg2—Mg2^iv	83.86 (4)
O5ⁱⁱⁱ—Ag1A—Ag1A^vi	45.55 (3)	O2^iv—Mg2—Mg2^iv	82.63 (4)
O5^iv—Ag1A—Ag1A^vi	130.57 (10)	O5ⁱ—Mg2—P2	151.29 (4)
Mg2—Ag1A—Ag1A^vi	70.23 (7)	O3^ix—Mg2—P2	66.25 (4)
Mg2^v—Ag1A—Ag1A^vi	122.57 (9)	O4—Mg2—P2	24.50 (3)
Ag1B^vi—Ag1A—Ag1A^vi	4.5 (3)	O4^iv—Mg2—P2	109.17 (4)
Ag1B^vii—Ag1A—Ag1A^vi	162.4 (6)	O1—Mg2—P2	94.16 (4)
O5ⁱ—Ag1A—Ag1A^vii	126.91 (10)	O2^iv—Mg2—P2	81.36 (4)
O5ⁱⁱ—Ag1A—Ag1A^vii	49.46 (4)	Mg2^iv—Mg2—P2	66.81 (2)
O5ⁱⁱⁱ—Ag1A—Ag1A^vii	130.57 (10)	O5ⁱ—Mg2—Ag1A	48.62 (8)
O5^iv—Ag1A—Ag1A^vii	45.55 (3)	O3^ix—Mg2—Ag1A	104.68 (4)
Mg2—Ag1A—Ag1A^vii	122.57 (9)	O4—Mg2—Ag1A	141.24 (8)
Mg2^v—Ag1A—Ag1A^vii	70.23 (7)	O4^iv—Mg2—Ag1A	68.99 (5)
Ag1B^vi—Ag1A—Ag1A^vii	162.4 (6)	O1—Mg2—Ag1A	120.08 (7)
Ag1B^vii—Ag1A—Ag1A^vii	4.5 (3)	O2^iv—Mg2—Ag1A	63.49 (8)
Ag1A^vi—Ag1A—Ag1A^vii	157.9 (3)	Mg2^iv—Mg2—Ag1A	106.54 (6)
O5ⁱ—Ag1B—O5ⁱⁱ	177.8 (10)	P2—Mg2—Ag1A	144.85 (7)
O5ⁱ—Ag1B—O5ⁱⁱⁱ	96.05 (5)	O5ⁱ—Mg2—P2^ix	77.41 (4)
O5ⁱⁱ—Ag1B—O5ⁱⁱⁱ	83.89 (5)	O3^ix—Mg2—P2^ix	23.55 (3)
O5ⁱ—Ag1B—O5^iv	83.89 (5)	O4—Mg2—P2^ix	96.44 (4)
O5ⁱⁱ—Ag1B—O5^iv	96.05 (5)	O4^iv—Mg2—P2^ix	173.57 (4)
O5ⁱⁱⁱ—Ag1B—O5^iv	176.9 (10)	O1—Mg2—P2^ix	88.39 (4)
O5ⁱ—Ag1B—Ag1B^vi	50.02 (3)	O2^iv—Mg2—P2^ix	102.49 (4)
O5ⁱⁱ—Ag1B—Ag1B^vi	129.88 (8)	Mg2^iv—Mg2—P2^ix	139.20 (3)
O5ⁱⁱⁱ—Ag1B—Ag1B^vi	46.03 (3)	P2—Mg2—P2^ix	73.940 (17)
O5^iv—Ag1B—Ag1B^vi	133.82 (10)	Ag1A—Mg2—P2^ix	111.92 (4)
O5ⁱ—Ag1B—Ag1B^vii	129.88 (8)	O5ⁱ—Mg2—Mg1	102.56 (4)
O5ⁱⁱ—Ag1B—Ag1B^vii	50.02 (3)	O3^ix—Mg2—Mg1	40.22 (3)
O5ⁱⁱⁱ—Ag1B—Ag1B^vii	133.82 (10)	O4—Mg2—Mg1	81.27 (4)
O5^iv—Ag1B—Ag1B^vii	46.03 (3)	O4^iv—Mg2—Mg1	122.61 (4)
Ag1B^vi—Ag1B—Ag1B^vii	176.0 (15)	O1—Mg2—Mg1	147.15 (4)
O5ⁱ—Ag1B—Ag1A^vi	50.19 (5)	O2^iv—Mg2—Mg1	39.90 (3)
O5ⁱⁱ—Ag1B—Ag1A^vi	129.49 (14)	Mg2^iv—Mg2—Mg1	105.43 (3)
O5ⁱⁱⁱ—Ag1B—Ag1A^vi	46.19 (4)	P2—Mg2—Mg1	62.814 (18)
O5^iv—Ag1B—Ag1A^vi	133.32 (16)	Ag1A—Mg2—Mg1	88.00 (4)
Ag1B^vi—Ag1B—Ag1A^vi	4.6 (3)	P2^ix—Mg2—Mg1	63.765 (15)
Ag1B^vii—Ag1B—Ag1A^vi	171.4 (12)	O5ⁱ—Mg2—Ag1B	44.9 (3)
O5ⁱ—Ag1B—Ag1A^vii	129.49 (14)	O3^ix—Mg2—Ag1B	104.30 (5)
O5ⁱⁱ—Ag1B—Ag1A^vii	50.19 (5)	O4—Mg2—Ag1B	144.9 (3)
O5ⁱⁱⁱ—Ag1B—Ag1A^vii	133.32 (16)	O4^iv—Mg2—Ag1B	70.47 (13)
O5^iv—Ag1B—Ag1A^vii	46.19 (4)	O1—Mg2—Ag1B	117.1 (2)
Ag1B^vi—Ag1B—Ag1A^vii	171.4 (12)	O2^iv—Mg2—Ag1B	67.0 (3)
Ag1B^vii—Ag1B—Ag1A^vii	4.6 (3)	Mg2^iv—Mg2—Ag1B	109.1 (2)
Ag1A^vi—Ag1B—Ag1A^vii	166.9 (9)	P2—Mg2—Ag1B	148.3 (3)
O5ⁱ—Ag1B—Mg2	37.3 (2)	Ag1A—Mg2—Ag1B	3.9 (2)
O5ⁱⁱ—Ag1B—Mg2	144.9 (8)	P2^ix—Mg2—Ag1B	110.03 (15)
O5ⁱⁱⁱ—Ag1B—Mg2	102.7 (3)	Mg1—Mg2—Ag1B	90.03 (16)
O5^iv—Ag1B—Mg2	79.2 (2)	O2—P1—O2^xi	111.36 (10)
Ag1B^vi—Ag1B—Mg2	66.0 (4)	O2—P1—O1	110.96 (6)
Ag1B^vii—Ag1B—Mg2	116.6 (6)	O2^xi—P1—O1	108.44 (6)
Ag1A^vi—Ag1B—Mg2	69.01 (18)	O2—P1—O1^xi	108.44 (6)
Ag1A^vii—Ag1B—Mg2	119.4 (3)	O2^xi—P1—O1^xi	110.95 (6)
O5ⁱ—Ag1B—Mg2^v	144.9 (8)	O1—P1—O1^xi	106.60 (10)
O5ⁱⁱ—Ag1B—Mg2^v	37.3 (2)	O4—P2—O5	110.74 (7)
O5ⁱⁱⁱ—Ag1B—Mg2^v	79.2 (2)	O4—P2—O3	111.02 (7)
O5^iv—Ag1B—Mg2^v	102.7 (3)	O5—P2—O3	109.06 (7)
Ag1B^vi—Ag1B—Mg2^v	116.6 (6)	O4—P2—O6	108.40 (7)
Ag1B^vii—Ag1B—Mg2^v	66.0 (4)	O5—P2—O6	107.86 (7)
Ag1A^vi—Ag1B—Mg2^v	119.4 (3)	O3—P2—O6	109.70 (7)
Ag1A^vii—Ag1B—Mg2^v	69.01 (18)	O4—P2—Mg2	34.24 (5)
Mg2—Ag1B—Mg2^v	109.3 (6)	O5—P2—Mg2	144.97 (5)
O5ⁱ—Ag1B—Mg1^vi	88.9 (5)	O3—P2—Mg2	91.84 (5)
O5ⁱⁱ—Ag1B—Mg1^vi	88.9 (5)	O6—P2—Mg2	90.03 (5)
O5ⁱⁱⁱ—Ag1B—Mg1^vi	88.4 (5)	O4—P2—Mg2^ix	136.27 (5)
O5^iv—Ag1B—Mg1^vi	88.4 (5)	O5—P2—Mg2^ix	106.49 (5)
Ag1B^vi—Ag1B—Mg1^vi	88.0 (8)	O3—P2—Mg2^ix	32.58 (5)
Ag1B^vii—Ag1B—Mg1^vi	88.0 (8)	O6—P2—Mg2^ix	80.34 (5)
Ag1A^vi—Ag1B—Mg1^vi	83.4 (5)	Mg2—P2—Mg2^ix	106.060 (17)
Ag1A^vii—Ag1B—Mg1^vi	83.4 (5)	P1—O1—Mg2	123.77 (7)
Mg2—Ag1B—Mg1^vi	125.3 (3)	P1—O2—Mg1^iv	126.47 (7)
Mg2^v—Ag1B—Mg1^vi	125.3 (3)	P1—O2—Mg2^iv	123.92 (7)
O2^viii—Mg1—O2^iv	156.91 (8)	Mg1^iv—O2—Mg2^iv	99.56 (5)
O2^viii—Mg1—O3^ix	87.86 (5)	P2—O3—Mg2^ix	123.87 (7)
O2^iv—Mg1—O3^ix	78.33 (5)	P2—O3—Mg1^ix	134.97 (7)
O2^viii—Mg1—O3ⁱⁱⁱ	78.33 (5)	Mg2^ix—O3—Mg1^ix	101.16 (5)
O2^iv—Mg1—O3ⁱⁱⁱ	87.86 (5)	P2—O4—Mg2	121.26 (7)
O3^ix—Mg1—O3ⁱⁱⁱ	106.45 (7)	P2—O4—Mg2^iv	140.95 (7)
O2^viii—Mg1—O6	108.09 (5)	Mg2—O4—Mg2^iv	94.21 (5)
O2^iv—Mg1—O6	88.61 (5)	P2—O5—Mg2^xii	139.84 (8)
O3^ix—Mg1—O6	82.80 (4)	P2—O5—Ag1B^xiii	104.2 (5)
O3ⁱⁱⁱ—Mg1—O6	169.20 (5)	Mg2^xii—O5—Ag1B^xiii	97.9 (5)
O2^viii—Mg1—O6^x	88.61 (5)	P2—O5—Ag1A^xiii	110.03 (12)
O2^iv—Mg1—O6^x	108.09 (5)	Mg2^xii—O5—Ag1A^xiii	91.67 (12)
O3^ix—Mg1—O6^x	169.20 (5)	Ag1B^xiii—O5—Ag1A^xiii	6.3 (4)
O3ⁱⁱⁱ—Mg1—O6^x	82.80 (4)	P2—O5—Ag1B^iv	111.6 (5)
O6—Mg1—O6^x	88.61 (7)	Mg2^xii—O5—Ag1B^iv	103.7 (5)
O2^viii—Mg1—Mg2^x	40.53 (3)	Ag1B^xiii—O5—Ag1B^iv	83.95 (5)
O2^iv—Mg1—Mg2^x	125.98 (4)	Ag1A^xiii—O5—Ag1B^iv	84.17 (8)
O3^ix—Mg1—Mg2^x	105.38 (4)	P2—O5—Ag1A^iv	105.79 (12)
O3ⁱⁱⁱ—Mg1—Mg2^x	38.62 (3)	Mg2^xii—O5—Ag1A^iv	109.53 (12)
O6—Mg1—Mg2^x	145.25 (4)	Ag1B^xiii—O5—Ag1A^iv	84.12 (8)
O6^x—Mg1—Mg2^x	78.19 (3)	Ag1A^xiii—O5—Ag1A^iv	84.99 (5)
O2^viii—Mg1—Mg2	125.98 (4)	Ag1B^iv—O5—Ag1A^iv	5.9 (4)
O2^iv—Mg1—Mg2	40.53 (3)	P2—O6—Mg1	125.56 (7)
O3^ix—Mg1—Mg2	38.62 (3)	P2—O6—H6	106.9
O3ⁱⁱⁱ—Mg1—Mg2	105.38 (4)	Mg1—O6—H6	126.3
O6—Mg1—Mg2	78.19 (3)

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6···O1^xii	0.86	1.68	2.5266 (17)	168

Symmetry code: (xii) −x+1/2, y+1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	AgMg₃(PO₄)(HPO₄)₂
M_r	467.73
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	296
a, b, c (Å)	11.9126 (5), 12.1197 (6), 6.4780 (3)
β (°)	113.812 (2)
V (Å³)	855.66 (7)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	3.21
Crystal size (mm)	0.31 × 0.16 × 0.12

Data collection
Diffractometer	Bruker X8 APEX
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.545, 0.680
No. of measured, independent and observed [I > 2σ(I)] reflections	10680, 2330, 1998
R_int	0.034
(sin θ/λ)_max (Å⁻¹)	0.866

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.026, 0.075, 1.08
No. of reflections	2330
No. of parameters	91
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.63, −1.28

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997) and DIAMOND (Brandenburg, 2006), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6···O1ⁱ	0.86	1.68	2.5266 (17)	168

Symmetry code: (i) −x+1/2, y+1/2, −z+1/2.

Acknowledgements

The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements.

References

Assani, A., Saadi, M. & El Ammari, L. (2010). Acta Cryst. E66, i74. Web of Science CrossRef IUCr Journals Google Scholar
Ben Smail, R. & Jouini, T. (2002). Acta Cryst. C58, i61–i62. Web of Science CrossRef CAS IUCr Journals Google Scholar
Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany. Google Scholar
Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Guesmi, A. & Driss, A. (2002). Acta Cryst. C58, i16–i17. Web of Science CrossRef CAS IUCr Journals Google Scholar
Hatert, F. (2008). J. Solid State Chem. 181, 1258–1272. Web of Science CrossRef CAS Google Scholar
Hatert, F., Keller, P., Lissner, F., Antenucci, D. & Fransolet, A. M. (2000). Eur. J. Mineral. 12, 847–857. CAS Google Scholar
Kacimi, M., Ziyad, M. & Hatert, F. (2005). Mater. Res. Bull. 40, 682–693. Web of Science CrossRef CAS Google Scholar
Korzenski, M. B., Schimek, G. L., Kolis, J. W. & Long, G. J. (1998). J. Solid State Chem. 139, 142–160. Web of Science CrossRef Google Scholar
Leroux, F., Mar, A., Guyomard, D. & Piffard, Y. (1995). J. Solid State Chem. 117, 206–212. CrossRef CAS Web of Science Google Scholar
Moore, P. B. (1971). Am. Mineral. 56, 1955–1975. CAS Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Stock, N. & Bein, T. (2003). Solid State Sci. 5, 1207–1210. Web of Science CrossRef CAS Google Scholar
Trad, K., Carlier, D., Croguennec, L., Wattiaux, A., Ben Amara, M. & Delmas, C. (2010). Chem. Mater. 22, 5554–5562. Web of Science CrossRef CAS Google Scholar

This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.