inorganic compounds
Acta Crystallographica Section E ugite, see: Anthony et al. (2003). For the mineralogy of three Structure Reports sulfate deposits of northern Chile including Mina Alcaparrosa, Online see: Bandy (1938). For the recently described new sulfate ISSN 1600-5368 mineral alcaparrosite, see: Kampf et al. (2012). For crystal structures of the related aluminium sulfate hydrates mendo- Redetermination of tamarugite, zite [NaAl(SO4)2 11H2O], sodium alum [NaAl(SO4)2 12H2O], alunogen [Al2(SO4)3 17H2O] and apjohnite [MnAl2(SO4)4 - NaAl(SO4)2 6H2O 22H2O], see: Fang & Robinson (1972); Cromer et al. (1967); Menchetti & Sabelli (1974, 1976). Kurt Mereiter
Institute of Chemical Technology and Analytics, Vienna University of Technology, Experimental Getreidemarkt 9/164SC, A-1060 Vienna, Austria Crystal data Correspondence e-mail: [email protected] ˚ 3 NaAl(SO4)2 6H2O V = 1136.57 (10) A Received 4 September 2013; accepted 10 September 2013 Mr = 350.19 Z =4 Monoclinic, P21=a Mo K radiation a = 7.3847 (3) A˚ = 0.66 mm 1 b = 25.2814 (15) A˚ T = 295 K Key indicators: single-crystal X-ray study; T = 295 K; mean (Al–O) = 0.001 A˚; c = 6.1097 (3) A˚ 0.48 0.25 0.20 mm R factor = 0.025; wR factor = 0.061; data-to-parameter ratio = 17.1. = 94.85 (2)
Data collection The crystal structure of tamarugite [sodium aluminium Bruker SMART CCD 17967 measured reflections bis(sulfate) hexahydrate] was redetermined from a single diffractometer 3316 independent reflections crystal from Mina Alcaparossa, near Cerritos Bayos, south- Absorption correction: multi-scan 2826 reflections with I >2 (I) (SADABS; Bruker, 1999) R = 0.029 west of Calama, Chile. In contrast to the previous work int Tmin = 0.74, Tmax = 0.88 [Robinson & Fang (1969). Am. Mineral. 54, 19–30], all non-H atoms were refined with anisotropic displacement parameters Refinement and H-atoms were located by difference Fourier methods and R[F 2 >2 (F 2)] = 0.025 194 parameters wR(F 2) = 0.061 H-atom parameters constrained refined from X-ray diffraction data. The structure is built up ˚ 3 3+ S = 1.14 Á max = 0.48 e A from nearly regular [Al(H O) ] octahedra and infinite ˚ 3 2 6 3316 reflections Á min = 0.36 e A 3 double-stranded chains [Na(SO4)2] that extend parallel to [001]. The Na+ cation has a strongly distorted octahedral Table 1 coordination by sulfate O atoms [Na—O = 2.2709 (11) – Selected bond lengths (A˚ ). ˚ 2.5117 (12) A], of which five are furnished by the chain- Na—O6 2.2709 (11) Al—O9W 1.8904 (10) building sulfate group S2O and one by the non-bridging Na—O3 2.3389 (12) Al—O14W 1.9054 (11) 4 i 3 Na—O8 2.4153 (12) S1—O3 1.4671 (10) sulfate group S1O4. The [Na(SO4)2] chain features an Na—O5ii 2.4814 (12) S1—O2 1.4738 (10) ii unusual centrosymmetric group formed by two NaO6 octa- Na—O7 2.5020 (11) S1—O1 1.4759 (10) i hedra and two S2O tetrahedra sharing five adjacent edges, Na—O7 2.5117 (12) S1—O4 1.4825 (10) 4 Al—O10W 1.8755 (10) S2—O8 1.4653 (10) one between two NaO6 octahedra and two each between the Al—O13W 1.8776 (11) S2—O6 1.4723 (10) Al—O11W 1.8816 (10) S2—O5 1.4814 (10) resulting double octahedron and two S2O4 tetrahedra. These groups are then linked into a double-stranded chain via Al—O12W 1.8816 (10) S2—O7 1.4826 (10) Symmetry codes: (i) x; y; z 1; (ii) x þ 1; y; z þ 1. corner-sharing between NaO6 octahedra and S2O4 tetrahedra. The S1O4 group, attached to Na in the terminal position, 3+ completes the chains. The [Al(H2O)6] octahedron (hAl—Oi Table 2 = 1.885 (11) A˚ ) donates 12 comparatively strong hydrogen Hydrogen-bond geometry (A˚ , ). bonds (O O = 2.6665 (14) – 2.7971 (15) A˚ ) to the sulfate O 3 D—H AD—H H AD AD—H A atoms of three neighbouring [Na(SO4)2] chains, helping to connect them in three dimensions, but with a prevalence O9W—H9A O2iii 0.80 2.00 2.7971 (15) 173 O9W—H9B O4iv 0.80 1.83 2.6282 (14) 178 parallel to (010), the cleavage plane of the mineral. Compared O10W—H10A O5ii 0.80 1.87 2.6665 (14) 173 with the previous work on tamarugite, the bond precision of O10W—H10B O6iii 0.80 1.78 2.5697 (14) 169 Al—O bond lengths as an example improved from 0.024 to O11W—H11A O7 0.80 1.83 2.6315 (14) 176 O11W—H11B O3 0.80 1.93 2.7236 (14) 175 0.001 A˚ . O12W—H12A O4iii 0.80 1.89 2.6787 (14) 171 O12W—H12B O2v 0.80 1.84 2.6330 (14) 169 O13W—H13A O1vi 0.80 1.86 2.6474 (14) 169 Related literature O13W—H13B O1vii 0.80 1.88 2.6698 (14) 171 O14W—H14A O5viii 0.80 2.18 2.7478 (15) 129 For the previous structure determination of tamarugite, see: O14W—H14B O8iii 0.80 1.96 2.7100 (17) 156 1 1 Robinson & Fang (1969). For mineralogical data of tamar- Symmetry codes: (ii) x þ 1; y; z þ 1; (iii) x 1; y; z; (iv) x 2; y þ 2; z; (v) 1 1 x 1; y; z þ 1; (vi) x; y; z þ 1; (vii) x 2; y þ 2; z þ 1; (viii) x þ 1; y; z þ 2.
Acta Cryst. (2013). E69, i63–i64 doi:10.1107/S1600536813025154 Kurt Mereiter i63 inorganic compounds
References Data collection: SMART (Bruker, 1999); cell refinement: SAINT Anthony, J. W., Bideaux, R. A., Bladh, K. W. & Nichols, M. C. (2003). Handbook of Mineralogy, Vol. V, Borates, Carbonates, Sulfates. Tucson: (Bruker, 1999); data reduction: SAINT; program(s) used to solve Mineral Data Publishing. structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine Bandy, M. C. (1938). Am. Mineral. 23, 669–760. structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Brandenburg, K. (2012). DIAMOND. Crystal Impact GbR, Bonn, Germany. DIAMOND (Brandenburg, 2012); software used to prepare material Bruker (1999). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, for publication: SHELXL97 and publCIF (Westrip, 2010). Wisconsin, USA. Cromer, D. T., Kay, M. I. & Larson, A. C. (1967). Acta Cryst. 22, 182–187. Fang, J. H. & Robinson, P. D. (1972). Am. Mineral. 57, 1081–1088. Kampf, A. R., Mills, S. J., Housley, R. M. & Williams, P. A. (2012). Mineral. Mag. 76, 851–861. Supplementary data and figures for this paper are available from the Menchetti, S. & Sabelli, C. (1974). Tschermaks Miner. Petr. Mitt. 21, 164–178. IUCr electronic archives (Reference: PJ2005). Menchetti, S. & Sabelli, C. (1976). Mineral. Mag. 40, 599–608. Robinson, P. D. & Fang, J. H. (1969). Am. Mineral. 55, 19–30. Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925.