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Volume 70 
Part 1 
Page i6  
January 2014  

Received 20 November 2013
Accepted 13 December 2013
Online 24 December 2013

Key indicators
Single-crystal X-ray study
T = 293 K
Mean [sigma](As-O) = 0.004 Å
Disorder in main residue
R = 0.038
wR = 0.112
Data-to-parameter ratio = 9.3
Details
Open access

The aluminoarsenate Na1.67K1.33Al3(AsO4)4

aLaboratoire des Materiaux et de Cristallochimie, Faculte des Sciences de Tunis, Tunisia
Correspondence e-mail: habib.boughzala@ipein.rnu.tn

The title compound, sodium potassium trialuminium tetra­kis­(orthoarsenate), was prepared by solid-state reactions. The anionic framework consists of corrugated layers parallel to (010) and is made up of corner-sharing AlO6 octa­hedra (site symmetries .2. and 2/m..) that are connected to isolated AsO4 tetra­hedra (site symmetries .2. and m..) through edge- and corner-sharing. The alkali cations are occupationally disordered. The two K+ cations [site symmetries .2. and m..; occupancies 0.314 (7) and 0.035 (12)] are situated in the inter­layer space, whereas the smaller Na+ cations [both with site symmetry m..; occupancies = 0.725 (14) and 0.112 (14)] are located in the cavities of the anionic framework. The K+ cations are surrounded by six and seven O atoms, the Na+ cations by seven and nine O atoms. The resulting coordination polyhedra of the two types of cations are highly distorted.

Related literature

For further information on this structure type, see: Friaa et al. (2003[Friaa, B. B., Boughzala, H. & Jouini, T. (2003). J. Solid State Chem. 173, 273-279.]); Haj Abdallah & Haddad (2012[Haj Abdallah, A. & Haddad, A. (2012). Acta Cryst. E68, i29.]). For background to the bond-valence method, see: Brown (2002[Brown, I. D. (2002). In The Chemical Bond in Inorganic Chemistry: The Bond Valence Model. Oxford University Press.]).

Experimental

Crystal data
  • Na1.67K1.33Al3(AsO4)4

  • Mr = 726.95

  • Orthorhombic, C m c e

  • a = 10.493 (1) Å

  • b = 20.395 (4) Å

  • c = 6.335 (4) Å

  • V = 1355.7 (9) Å3

  • Z = 4

  • Mo K[alpha] radiation

  • [mu] = 10.53 mm-1

  • T = 293 K

  • 0.40 × 0.10 × 0.07 mm

Data collection
  • Enraf-Nonius CAD-4 diffractometer

  • Absorption correction: [psi] scan (North et al., 1968[North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.]) Tmin = 0.130, Tmax = 0.332

  • 1723 measured reflections

  • 780 independent reflections

  • 717 reflections with I > 2[sigma](I)

  • Rint = 0.062

  • 2 standard reflections every 120 min intensity decay: 1.1%

Refinement
  • R[F2 > 2[sigma](F2)] = 0.038

  • wR(F2) = 0.112

  • S = 1.15

  • 780 reflections

  • 84 parameters

  • 1 restraint

  • [Delta][rho]max = 2.38 e Å-3

  • [Delta][rho]min = -1.33 e Å-3

Table 1
Selected bond lengths (Å)

As1-O1 1.642 (5)
As1-O2i 1.678 (3)
As1-O2 1.678 (3)
As1-O3 1.694 (4)
As2-O4ii 1.648 (3)
As2-O4 1.648 (3)
As2-O5 1.729 (3)
As2-O5ii 1.729 (3)
Al1-O3 1.827 (5)
Al1-O3iii 1.827 (5)
Al1-O5iii 1.947 (3)
Al1-O5iv 1.947 (3)
Al1-O5i 1.947 (3)
Al1-O5 1.947 (3)
Al2-O2ii 1.817 (3)
Al2-O2 1.817 (3)
Al2-O4v 1.924 (3)
Al2-O4vi 1.924 (3)
Al2-O5ii 1.991 (3)
Al2-O5 1.991 (3)
Symmetry codes: (i) -x, y, z; (ii) [-x+{\script{1\over 2}}, y, -z+{\script{1\over 2}}]; (iii) -x, -y, -z; (iv) x, -y, -z; (v) [-x+{\script{1\over 2}}, -y, z-{\script{1\over 2}}]; (vi) x, -y, -z+1.

Data collection: CAD-4 EXPRESS (Enraf-Nonius, 1994[Enraf-Nonius (1994). CAD-4 EXPRESS. Enraf-Nonius, Delft, The Nether- lands.]); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995[Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 2006[Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: publCIF (Westrip, 2010[Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.]).


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: WM2786 ).


References

Brandenburg, K. (2006). DIAMOND. Crystal Impact GbR, Bonn, Germany.
Brown, I. D. (2002). In The Chemical Bond in Inorganic Chemistry: The Bond Valence Model. Oxford University Press.
Enraf-Nonius (1994). CAD-4 EXPRESS. Enraf-Nonius, Delft, The Nether- lands.
Friaa, B. B., Boughzala, H. & Jouini, T. (2003). J. Solid State Chem. 173, 273-279.  [Web of Science] [CrossRef] [ChemPort]
Haj Abdallah, A. & Haddad, A. (2012). Acta Cryst. E68, i29.  [CrossRef] [IUCr Journals]
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.  [CrossRef] [IUCr Journals]
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [ChemPort] [IUCr Journals]
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.  [Web of Science] [CrossRef] [ChemPort] [IUCr Journals]


Acta Cryst (2014). E70, i6  [ doi:10.1107/S1600536813033850 ]

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