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Rietveld refinement of the langbeinite-type mixed-metal phosphate K2Ni0.5Zr1.5(PO4)3

aDepartment of Inorganic Chemistry, Taras Shevchenko National University, 64/13, Volodymyrska St, 01601 Kyiv, Ukraine
*Correspondence e-mail: zvigo@yandex.ru

(Received 8 April 2014; accepted 11 June 2014; online 18 June 2014)

Dipotassium [nickel(II) zirconium(IV)] tris­(orthophosphate) was prepared from a self-flux in the system K2O–P2O5–NiO–K2ZrF6. The title compound belongs to the langbeinite family and is built up from two [MO6] octa­hedra [M = Ni:Zr with mixed occupancy in ratios of 0.21 (4):0.79 (4) and 0.29 (4):0.71 (4), respectively] and [PO4] tetra­hedra inter­linked via vertices into a 3[M2(PO4)3] framework. Two independent K+ cations are located in large cavities of the framework, with coordination numbers to O2− anions of nine and twelve. The K, Ni, and Zr sites are located on threefold rotation axes.

Related literature

For the structure of the mineral langbeinite, see: Zemann & Zemann (1957[Zemann, A. & Zemann, J. (1957). Acta Cryst. 10, 409-413.]). For langbeinite-related phosphates based on different pairs of polyvalent metals, see: Wulff et al. (1992[Wulff, H., Guth, U. & Loescher, B. (1992). Powder Diffr. 7, 103-106.]) for K2REZr(PO4)3 (RE = Y, Gd); Orlova et al. (2003[Orlova, A. I., Trubach, I. G., Kurazhkovskaya, V. S., Pertierra, P., Salvado, M. A., Garcia-Granda, S., Khainakov, S. A. & Garcia, J. R. (2003). J. Solid State Chem. 173, 314-318.]) for K2FeZr(PO4)3; Ogorodnyk et al. (2007a[Ogorodnyk, I. V., Zatovsky, I. V., Baumer, V. N., Slobodyanik, N. S., Shishkin, O. V. & Vorona, I. P. (2007a). J. Solid State Chem. 180, 2838-2844.]) for K1.96Mn0.57Zr1.43(PO4)3 and K1.93Mn0.53Hf1.47(PO4)3; Ogorodnyk et al. (2007b[Ogorodnyk, I. V., Zatovsky, I. V. & Slobodyanik, N. S. (2007b). Russ. J. Inorg. Chem. 52, 121-125.]) for K2Ni0.5Ti1.5(PO4)3. For the profile function used in the Rietveld refinement, see: Thompson et al. (1987[Thompson, P., Cox, D. E. & Hastings, J. B. (1987). J. Appl. Cryst. 20, 79-83.]).

Experimental

Crystal data
  • K2Ni0.5Zr1.5(PO4)3

  • Mr = 529.29

  • Cubic, P 21 3

  • a = 10.15724 (13) Å

  • V = 1047.92 (2) Å3

  • Z = 4

  • Cu Kα radiation, λ = 1.540598 Å

  • T = 293 K

  • Flat sheet, 25 × 25 mm

Data collection
  • Shimadzu LabX XRD-6000 diffractometer

  • Specimen mounting: glass container

  • Data collection mode: reflection

  • Scan method: step

  • 2θmin = 10.910°, 2θmax = 104.911°, 2θstep = 0.020°

Refinement
  • Rp = 0.100

  • Rwp = 0.134

  • Rexp = 0.034

  • RBragg = 0.041

  • R(F) = 0.035

  • χ2 = 15.761

  • 4701 data points

  • 107 parameters

  • 2 restraints

Table 1
Selected bond lengths (Å)

K1—O1i 2.956 (16)
K1—O2ii 3.165 (14)
K1—O4ii 3.325 (14)
K2—O3ii 2.973 (15)
K2—O2iii 3.026 (16)
K2—O4ii 3.127 (15)
K2—O4iii 3.332 (15)
Zr1—O1 2.070 (14)
Zr1—O2iv 2.098 (14)
Zr2—O4 2.036 (12)
Zr2—O3i 2.041 (16)
P1—O3 1.530 (18)
P1—O4 1.523 (13)
P1—O2 1.515 (15)
P1—O1 1.493 (16)
Symmetry codes: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [-x+{\script{3\over 2}}, -y+1, z+{\script{1\over 2}}]; (iii) [-z+1, x+{\script{1\over 2}}, -y+{\script{3\over 2}}]; (iv) [x-{\script{1\over 2}}, -y+{\script{1\over 2}}, -z].

Data collection: PCXRD (Shimadzu, 2006[Shimadzu (2006). PCXRD. Shimadzu Corporation, Kyoto, Japan.]); cell refinement: DICVOL-2004 (Boultif & Louër, 2004[Boultif, A. & Louër, D. (2004). J. Appl. Cryst. 37, 724-731.]); data reduction: FULLPROF (Rodriguez-Carvajal, 2006[Rodriguez-Carvajal, J. (2006). FULLPROF. Laboratoire León Brillouin (CEA-CNRS), France.]); program(s) used to solve structure: FULLPROF; program(s) used to refine structure: FULLPROF; molecular graphics: DIAMOND (Brandenburg, 1999[Brandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]) and enCIFer (Allen et al., 2004[Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335-338.]).

Supporting information


Comment top

Phosphates of the langbeinite structure type are considered as favorable for environmentally safe crystalline forms of radioactive waste solidification (Orlova et al., 2003). Langbeinite-type frameworks 3[M2(PO4)3] can be composed of various polyvalent metal pairs, for example, K2Ni0.5Ti1.5(PO4)3 (Ogorodnyk et al., 2007b), K1.96Mn0.57Zr1.43(PO4)3 and K1.93Mn0.53Hf1.47(PO4)3 (Ogorodnyk et al., 2007b), K2FeZr(PO4)3 (Orlova et al., 2003), K2REZr(PO4)3, RE = Y, Gd (Wulff et al., 1992). Herein the powder X-ray refinement of a phosphate, structurally isotypic with the mineral langbenite, K2Mg2(SO4)3 (Zemann & Zemann, 1957), K2Ni0.5Zr1.5(PO4)3, (I), is presented (Fig. 1).

The K, Ni, and Zr sites lie on threefold rotation axes in positions 4 a with the sequence {(Zr,Ni)1—(Zr,Ni)2—K1—K2} where (Zr,Ni)1 and (Zr,Ni)2 are metal sites with a mixed occupancy (Fig. 2). P and O atoms are located in 12 b positions.

The structure of (I) contains two independent [(Zr,Ni)O6] octahedra and one [PO4] tetrahedron which are linked together via common vertices, forming a three-dimensional framework (Fig. 3). The (Zr,Ni)–O bond lengths are 2.070 (14) Å, 2.098 (14) Å and 2.036 (12) Å, 2.041 (16) Å for [(Zr,Ni)1O6] and [(Zr,Ni)2O6], respectively. It should be noted that the occupancy of the metal sites by Ni2+ is slightly different (0.21 (4) for the M1 site and 0.29 (4) for the M2 site) whereas in case of K2Ni0.5Ti1.5(PO4)3 (Ogorodnyk et al., 2007b) Ni2+ ions are almost equally distributed (occupancy of 0.25 for both positions), with ((Ti,Ni)—O bonds ranging from 1.938 (5) to 1.962 (5) Å. The three-dimensional framework 3[(Zr,Ni)2(PO4)3] has large closed cavities where the two independent K+ cations are located. K1 is coordinated by nine O atoms, while K2 is surrounded by twelve O atoms (Fig. 4), with K—O bond lengths ranging from 2.956 (16) to 3.332 (15) Å (Table 1).

Related literature top

For the structure of the mineral langbeinite, see: Zemann & Zemann (1957). For langbeinite-related phosphates based on different pairs of polyvalent metals, see: Wulff et al. (1992) for K2REZr(PO4)3 (RE = Y, Gd); Orlova et al. (2003) for K2FeZr(PO4)3; Ogorodnyk et al. (2007a) for K1.96Mn0.57Zr1.43(PO4)3 and K1.93Mn0.53Hf1.47(PO4)3; Ogorodnyk et al. (2007b) for K2Ni0.5Ti1.5(PO4)3. For the profile function used in the Rietveld refinement, see: Thompson et al. (1987).

Experimental top

A well-ground mixture of 11.8 g KPO3 and 1.12 g NiO was placed in a platinum crucible and then was heated up to 1273 K. The temperature was kept constant during one hour and after that it was decreased to 1173 K. 4.25 g of K2ZrF6 were added to the flux under stirring with a platinum stirrer (initial K:P, Zr:P and Zr:Ni ratio equal to 1.3, 0.15, and 1.0, respectively). The crystallization of the melt was performed in the temperature range from 1173 to 913 K at an rate of 25 K/h. Finally, the crucible was cooled down to room temperature. The obtained material of (I) was recovered by washing with hot deionized water. The small crystals of (I) had the form of regular tetrahedra and were of light-yellow colour. The atomic ratio of the elements in (I) was found to be 4:1:3:6 for K/Ni/Zr/P, respectively: The sample was dissolved in 80% sulfuric acid under heating. The amount of the elements was then determined by atomic emission spectroscopy with inductive coupled plasma, AES-ICP, Spectroflame Modula ICP "Spectro".

Refinement top

The powder pattern of (I) was indexed in the cubic system using DICVOL-2004 (Boultif & Louër, 2004). The pattern indexing showed that the sample was a single phase. Atomic coordinates of K1.96Mn0.57Zr1.43(PO4)3 (Ogorodnyk et al., 2007a) were used during Rietveld refinement as a starting model. For profile refinement a pseudo-Voigt function with axial divergence asymmetry (Thompson et al., 1987) was used. First, the scaling factor, background, cell parameters etc. were refined during profile matching. Atomic coordinates were then refined during the next step. Atomic coordinates and displacement parameters of corresponding Zr and Ni sites were constrained to be the same. Isotropic displacement parameters of all atoms were appended to the refinement. The occupancies of K, Ni and Zr were refined taking into account that the occupancies of the hexacoordinated metal site should be equal to unity which was done using occupancy constraints. As the occupancy of the K sites was found to be 1, the occupancy factors of K1 and K2 were fixed at 1. The displacement factors of the O atoms were spread over a large range which is meaningless in this case due to the quality of the powder diffraction data. Thus Uiso values for all O atoms were constrained to be equal. As a result, the values of Uiso and their e.s.d.'s have close values. At the final refinement cycles two geometric restraints were applied to the lengths of P—O bonds because their values were unsatisfactory for the model (without restraints, one was 1.44 Å while another was close to 1.57 Å). Experimental, calculated and difference patterns are shown in Fig. 1.

Structure description top

Phosphates of the langbeinite structure type are considered as favorable for environmentally safe crystalline forms of radioactive waste solidification (Orlova et al., 2003). Langbeinite-type frameworks 3[M2(PO4)3] can be composed of various polyvalent metal pairs, for example, K2Ni0.5Ti1.5(PO4)3 (Ogorodnyk et al., 2007b), K1.96Mn0.57Zr1.43(PO4)3 and K1.93Mn0.53Hf1.47(PO4)3 (Ogorodnyk et al., 2007b), K2FeZr(PO4)3 (Orlova et al., 2003), K2REZr(PO4)3, RE = Y, Gd (Wulff et al., 1992). Herein the powder X-ray refinement of a phosphate, structurally isotypic with the mineral langbenite, K2Mg2(SO4)3 (Zemann & Zemann, 1957), K2Ni0.5Zr1.5(PO4)3, (I), is presented (Fig. 1).

The K, Ni, and Zr sites lie on threefold rotation axes in positions 4 a with the sequence {(Zr,Ni)1—(Zr,Ni)2—K1—K2} where (Zr,Ni)1 and (Zr,Ni)2 are metal sites with a mixed occupancy (Fig. 2). P and O atoms are located in 12 b positions.

The structure of (I) contains two independent [(Zr,Ni)O6] octahedra and one [PO4] tetrahedron which are linked together via common vertices, forming a three-dimensional framework (Fig. 3). The (Zr,Ni)–O bond lengths are 2.070 (14) Å, 2.098 (14) Å and 2.036 (12) Å, 2.041 (16) Å for [(Zr,Ni)1O6] and [(Zr,Ni)2O6], respectively. It should be noted that the occupancy of the metal sites by Ni2+ is slightly different (0.21 (4) for the M1 site and 0.29 (4) for the M2 site) whereas in case of K2Ni0.5Ti1.5(PO4)3 (Ogorodnyk et al., 2007b) Ni2+ ions are almost equally distributed (occupancy of 0.25 for both positions), with ((Ti,Ni)—O bonds ranging from 1.938 (5) to 1.962 (5) Å. The three-dimensional framework 3[(Zr,Ni)2(PO4)3] has large closed cavities where the two independent K+ cations are located. K1 is coordinated by nine O atoms, while K2 is surrounded by twelve O atoms (Fig. 4), with K—O bond lengths ranging from 2.956 (16) to 3.332 (15) Å (Table 1).

For the structure of the mineral langbeinite, see: Zemann & Zemann (1957). For langbeinite-related phosphates based on different pairs of polyvalent metals, see: Wulff et al. (1992) for K2REZr(PO4)3 (RE = Y, Gd); Orlova et al. (2003) for K2FeZr(PO4)3; Ogorodnyk et al. (2007a) for K1.96Mn0.57Zr1.43(PO4)3 and K1.93Mn0.53Hf1.47(PO4)3; Ogorodnyk et al. (2007b) for K2Ni0.5Ti1.5(PO4)3. For the profile function used in the Rietveld refinement, see: Thompson et al. (1987).

Computing details top

Data collection: PCXRD (Shimadzu, 2006); cell refinement: DICVOL-2004 (Boultif & Louër, 2004); data reduction: FULLPROF (Rodriguez-Carvajal, 2006); program(s) used to solve structure: FULLPROF (Rodriguez-Carvajal, 2006); program(s) used to refine structure: FULLPROF (Rodriguez-Carvajal, 2006); molecular graphics: DIAMOND (Brandenburg, 1999); software used to prepare material for publication: PLATON (Spek, 2009) and enCIFer (Allen et al., 2004).

Figures top
[Figure 1] Fig. 1. Results of the Rietveld refinement of K2Ni0.5Zr1.5(PO4)3. Experimental (dots), calculated (red curve) and difference (blue curve) data.
[Figure 2] Fig. 2. A view of the asymmetric unit of K2Ni0.5Zr1.5(PO4)3. Displacement ellipsoid are drawn at the 50% probability level.
[Figure 3] Fig. 3. A projection of the structure of (I) along [111]. PO4 tetrahedra are pink, (Zr,Ni)1O6 octahedra are turquoise, (Zr,Ni)2O6 octahedra are green, K+ cations are shown as yellow spheres.
[Figure 4] Fig. 4. The O environment of K1+ and K2+ cations for (I). Displacement ellipsoid are drawn at the 50% probability level.
Dipotassium [nickel(II) zirconium(IV)] tris(orthophosphate) top
Crystal data top
K2Ni0.5Zr1.5(PO4)3Dx = 3.355 Mg m3
Mr = 529.29Cu Kα radiation, λ = 1.540598 Å
Cubic, P213T = 293 K
Hall symbol: P 2ac 2ab 3Particle morphology: isometric
a = 10.15724 (13) Åyellow
V = 1047.92 (2) Å3flat sheet, 25 × 25 mm
Z = 4Specimen preparation: Prepared at 293 K and 101.3 kPa
Data collection top
Shimadzu LabX XRD-6000
diffractometer
Data collection mode: reflection
Radiation source: X-ray tube, X-rayScan method: step
Graphite monochromator2θmin = 10.910°, 2θmax = 104.911°, 2θstep = 0.020°
Specimen mounting: glass container
Refinement top
Rp = 0.100107 parameters
Rwp = 0.1342 restraints
Rexp = 0.0349 constraints
RBragg = 0.041 Standard least squares refinement
R(F) = 0.035(Δ/σ)max = 0.001
4701 data pointsBackground function: Linear Interpolation between a set background points with refinable heights
Profile function: Thompson-Cox-Hastings pseudo-Voigt * Axial divergence asymmetryPreferred orientation correction: March-Dollase Numeric Multiaxial Function
Crystal data top
K2Ni0.5Zr1.5(PO4)3Z = 4
Mr = 529.29Cu Kα radiation, λ = 1.540598 Å
Cubic, P213T = 293 K
a = 10.15724 (13) Åflat sheet, 25 × 25 mm
V = 1047.92 (2) Å3
Data collection top
Shimadzu LabX XRD-6000
diffractometer
Scan method: step
Specimen mounting: glass container2θmin = 10.910°, 2θmax = 104.911°, 2θstep = 0.020°
Data collection mode: reflection
Refinement top
Rp = 0.100R(F) = 0.035
Rwp = 0.1344701 data points
Rexp = 0.034107 parameters
RBragg = 0.0412 restraints
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/UeqOcc. (<1)
K10.7043 (6)0.7043 (6)0.7043 (6)0.054 (5)*
K20.9317 (7)0.9317 (7)0.9317 (7)0.052 (4)*
Zr10.1448 (2)0.1448 (2)0.1448 (2)0.007 (2)*0.79 (4)
Zr20.4146 (3)0.4146 (3)0.4146 (3)0.004 (2)*0.71 (4)
Ni10.1448 (2)0.1448 (2)0.1448 (2)0.007 (2)*0.21 (4)
Ni20.4146 (3)0.4146 (3)0.4146 (3)0.004 (2)*0.29 (4)
P10.4581 (6)0.2296 (8)0.1286 (7)0.004 (2)*
O10.3180 (14)0.2335 (14)0.0844 (15)0.003 (2)*
O20.5417 (12)0.2950 (14)0.0238 (14)0.003 (2)*
O30.5025 (12)0.0869 (16)0.1471 (13)0.003 (2)*
O40.4729 (14)0.3039 (12)0.2580 (10)0.003 (2)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
???????
Geometric parameters (Å, º) top
K1—O1i2.956 (16)Zr1—O1xiii2.070 (14)
K1—O2ii3.165 (14)Zr1—O2xiv2.098 (14)
K1—O4ii3.325 (14)Zr2—O42.036 (12)
K1—O1iii2.956 (16)Zr2—O3i2.041 (16)
K1—O2iv3.165 (14)Zr2—O4xi2.036 (12)
K1—O4iv3.325 (14)Zr2—O3iii2.041 (16)
K1—O1v2.956 (16)Zr2—O4xiii2.036 (12)
K1—O2vi3.165 (14)Zr2—O3v2.041 (16)
K1—O4vi3.325 (14)Ni1—O2xii2.098 (14)
K2—O3ii2.973 (15)Ni1—O1xiii2.070 (14)
K2—O2vii3.026 (16)Ni1—O2xiv2.098 (14)
K2—O4ii3.127 (15)Ni1—O1xi2.070 (14)
K2—O4vii3.332 (15)Ni1—O12.070 (14)
K2—O3iv2.973 (15)Ni1—O2x2.098 (14)
K2—O2viii3.026 (16)Ni2—O42.036 (12)
K2—O4iv3.127 (15)Ni2—O3v2.041 (16)
K2—O4viii3.332 (15)Ni2—O3i2.041 (16)
K2—O3vi2.973 (15)Ni2—O4xi2.036 (12)
K2—O2ix3.026 (16)Ni2—O3iii2.041 (16)
K2—O4vi3.127 (15)Ni2—O4xiii2.036 (12)
K2—O4ix3.332 (15)P1—O31.530 (18)
Zr1—O12.070 (14)P1—O41.523 (13)
Zr1—O2x2.098 (14)P1—O21.515 (15)
Zr1—O1xi2.070 (14)P1—O11.493 (16)
Zr1—O2xii2.098 (14)
O1—Zr1—O2x93.2 (5)O1—Ni1—O2x93.2 (5)
O1—Zr1—O1xi90.6 (6)O1—Ni1—O1xi90.6 (6)
O1—Zr1—O2xii175.9 (5)O1—Ni1—O2xii175.9 (5)
O1—Zr1—O1xiii90.6 (6)O1—Ni1—O1xiii90.6 (6)
O1—Zr1—O2xiv87.7 (6)O1—Ni1—O2xiv87.7 (6)
O1xi—Zr1—O2x87.7 (6)O1xi—Ni1—O2x87.7 (6)
O2x—Zr1—O2xii88.6 (5)O2x—Ni1—O2xii88.6 (5)
O1xiii—Zr1—O2x175.9 (5)O1xiii—Ni1—O2x175.9 (5)
O2x—Zr1—O2xiv88.6 (5)O2x—Ni1—O2xiv88.6 (5)
O1xi—Zr1—O2xii93.2 (5)O4xi—Ni2—O4xiii87.5 (5)
O1xi—Zr1—O1xiii90.6 (6)O3v—Ni2—O4xi170.8 (5)
O1xi—Zr1—O2xiv175.9 (5)O3iii—Ni2—O4xiii84.5 (5)
O1xiii—Zr1—O2xii87.7 (6)O3iii—Ni2—O3v92.1 (5)
O2xii—Zr1—O2xiv88.6 (5)O3v—Ni2—O4xiii96.5 (5)
O1xiii—Zr1—O2xiv93.2 (5)O3i—Ni2—O3iii92.1 (5)
O3i—Zr2—O496.5 (5)O3i—Ni2—O496.5 (5)
O4—Zr2—O4xi87.5 (5)O4—Ni2—O4xi87.5 (5)
O3iii—Zr2—O4170.8 (5)O3iii—Ni2—O4170.8 (5)
O4—Zr2—O4xiii87.5 (5)O4—Ni2—O4xiii87.5 (5)
O3v—Zr2—O484.5 (5)O3v—Ni2—O484.5 (5)
O3i—Zr2—O4xi84.5 (5)O3i—Ni2—O4xi84.5 (5)
O3i—Zr2—O3iii92.1 (5)O3iii—Ni2—O4xi96.5 (5)
O3i—Zr2—O4xiii170.8 (5)O3i—Ni2—O4xiii170.8 (5)
O3i—Zr2—O3v92.1 (5)O3i—Ni2—O3v92.1 (5)
O3iii—Zr2—O4xi96.5 (5)O3—P1—O4109.5 (8)
O4xi—Zr2—O4xiii87.5 (5)O1—P1—O2108.1 (9)
O3v—Zr2—O4xi170.8 (5)O1—P1—O3110.1 (9)
O3iii—Zr2—O4xiii84.5 (5)O1—P1—O4109.9 (9)
O3iii—Zr2—O3v92.1 (5)O2—P1—O3109.7 (8)
O3v—Zr2—O4xiii96.5 (5)O2—P1—O4109.5 (9)
O1xi—Ni1—O2xii93.2 (5)Zr1—O1—P1135.2 (10)
O1xi—Ni1—O1xiii90.6 (6)Ni1—O1—P1135.2 (10)
O1xi—Ni1—O2xiv175.9 (5)Zr1xv—O2—P1168.8 (10)
O1xiii—Ni1—O2xii87.7 (6)Zr2xvi—O3—P1153.7 (9)
O2xii—Ni1—O2xiv88.6 (5)Zr2—O4—P1156.8 (9)
O1xiii—Ni1—O2xiv93.2 (5)Ni2—O4—P1156.8 (9)
Symmetry codes: (i) x+1, y+1/2, z+1/2; (ii) x+3/2, y+1, z+1/2; (iii) z+1/2, x+1, y+1/2; (iv) y+1, z+1/2, x+3/2; (v) y+1/2, z+1/2, x+1; (vi) z+1/2, x+3/2, y+1; (vii) z+1, x+1/2, y+3/2; (viii) y+3/2, z+1, x+1/2; (ix) x+1/2, y+3/2, z+1; (x) x1/2, y+1/2, z; (xi) z, x, y; (xii) z, x1/2, y+1/2; (xiii) y, z, x; (xiv) y+1/2, z, x1/2; (xv) x+1/2, y+1/2, z; (xvi) x+1, y1/2, z+1/2.
Selected bond lengths (Å) top
K1—O1i2.956 (16)Zr1—O2iv2.098 (14)
K1—O2ii3.165 (14)Zr2—O42.036 (12)
K1—O4ii3.325 (14)Zr2—O3i2.041 (16)
K2—O3ii2.973 (15)P1—O31.530 (18)
K2—O2iii3.026 (16)P1—O41.523 (13)
K2—O4ii3.127 (15)P1—O21.515 (15)
K2—O4iii3.332 (15)P1—O11.493 (16)
Zr1—O12.070 (14)
Symmetry codes: (i) x+1, y+1/2, z+1/2; (ii) x+3/2, y+1, z+1/2; (iii) z+1, x+1/2, y+3/2; (iv) x1/2, y+1/2, z.
 

References

First citationAllen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationBoultif, A. & Louër, D. (2004). J. Appl. Cryst. 37, 724–731.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationBrandenburg, K. (1999). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationOgorodnyk, I. V., Zatovsky, I. V., Baumer, V. N., Slobodyanik, N. S., Shishkin, O. V. & Vorona, I. P. (2007a). J. Solid State Chem. 180, 2838–2844.  Web of Science CrossRef CAS Google Scholar
First citationOgorodnyk, I. V., Zatovsky, I. V. & Slobodyanik, N. S. (2007b). Russ. J. Inorg. Chem. 52, 121–125.  Web of Science CrossRef Google Scholar
First citationOrlova, A. I., Trubach, I. G., Kurazhkovskaya, V. S., Pertierra, P., Salvado, M. A., Garcia–Granda, S., Khainakov, S. A. & Garcia, J. R. (2003). J. Solid State Chem. 173, 314–318.  Web of Science CrossRef CAS Google Scholar
First citationRodriguez-Carvajal, J. (2006). FULLPROF. Laboratoire León Brillouin (CEA–CNRS), France.  Google Scholar
First citationShimadzu (2006). PCXRD. Shimadzu Corporation, Kyoto, Japan.  Google Scholar
First citationSpek, A. L. (2009). Acta Cryst. D65, 148–155.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationThompson, P., Cox, D. E. & Hastings, J. B. (1987). J. Appl. Cryst. 20, 79–83.  CrossRef CAS Web of Science IUCr Journals Google Scholar
First citationWulff, H., Guth, U. & Loescher, B. (1992). Powder Diffr. 7, 103–106.  CrossRef CAS Google Scholar
First citationZemann, A. & Zemann, J. (1957). Acta Cryst. 10, 409–413.  CrossRef CAS IUCr Journals Web of Science Google Scholar

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