Kôzulite, an Mn-rich alkali amphibole

The crystal structure of kôzulite, an Mn-rich alkali amphibole with the ideal formula NaNa₂[Mn₄²⁺(Fe³⁺,Al)]Si₈O₂₂(OH)₂, tris­odium tetra­manganese iron/aluminium octa­silicate dihydroxide, was refined from a natural specimen with composition (K_0.20Na_0.80)(Na_1.60Ca_0.18Mn²⁺_0.22)(Mn²⁺_2.14Mn³⁺_0.25Mg_2.20Fe³⁺_0.27Al_0.14)(Si_7.92Al_0.06Ti_0.02)O₂₂[(OH)_1.86F_0.14]. The site occupancies determined from the refinements are M1 = 0.453 (1) Mn + 0.547 (1) Mg, M2 = 0.766 (1) Mn + 0.234 (1) Mg, and M3 = 0.257 (1) Mn + 0.743 (1) Mg, where Mn and Mg represent (Mn+Fe) and (Mg+Al), respectively. The average M-O bond lengths are 2.064 (1), 2.139 (1), and 2.060 (1) Å for the M1, M2, and M3 sites, respectively, indicating the preference of large Mn²⁺ for the M2 site. Four partially occupied amphibole A sites were revealed from the refinement, with A(m) = 0.101 (4) K, A(m)' = 0.187 (14) Na, A(2) = 0.073 (6) Na, and A(1) = 0.056 (18) Na, in accord with the result derived from microprobe analysis (0.20 K + 0.80 Na), considering experimental uncertainties.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](Si-O) = 0.001 Å
Some non-H atoms missing
• Disorder in main residue
• R factor = 0.023
• wR factor = 0.067
• Data-to-parameter ratio = 17.8

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT974_ALERT_2_A Large Calcd. Negative Residual Density on    Mn1     -28.19 eA-3
PLAT974_ALERT_2_A Large Calcd. Negative Residual Density on   Mn1#     -28.19 eA-3
PLAT974_ALERT_2_A Large Calcd. Negative Residual Density on   Mn3#      -6.99 eA-3
PLAT974_ALERT_2_A Large Calcd. Negative Residual Density on   Mg2#      -6.99 eA-3
PLAT974_ALERT_2_A Large Calcd. Negative Residual Density on   Mn2#      -6.91 eA-3
PLAT974_ALERT_2_A Large Calcd. Negative Residual Density on   Mg1#      -6.91 eA-3
PLAT051_ALERT_1_A Mu(calc) and Mu(CIF) Ratio Differs from 1.0 by .      23.07 Perc.
PLAT070_ALERT_1_A Duplicate Atomic Label on INPUT ................    <I>M</I
PLAT070_ALERT_1_A Duplicate Atomic Label on INPUT ................    <I>M</I
PLAT070_ALERT_1_A Duplicate Atomic Label on INPUT ................    <I>M</I
PLAT070_ALERT_1_A Duplicate Atomic Label on INPUT ................    <I>M</I
PLAT701_ALERT_1_A Bond    Calc  3.8293(12), Rep  2.0197(11), Dev..    1508.00 Sigma
              <I>M<-O4      1.555   7.556                    #          7
PLAT701_ALERT_1_A Bond    Calc  4.7795(11), Rep  2.0197(11), Dev..    2508.91 Sigma
              <I>M<-O4      1.555   8.454                    #          8
PLAT701_ALERT_1_A Bond    Calc  4.8116(11), Rep  2.1425(11), Dev..    2426.45 Sigma
              <I>M<-O2      1.555   1.554                    #          9
PLAT701_ALERT_1_A Bond    Calc  2.0553(11), Rep  2.1425(11), Dev..      79.27 Sigma
              <I>M<-O2      1.555   2.556                    #         10
PLAT701_ALERT_1_A Bond    Calc  3.6711(11), Rep  2.2554(10), Dev..    1287.00 Sigma
              <I>M<-O1      1.555   2.555                    #         11
PLAT701_ALERT_1_A Bond    Calc  2.1147(10), Rep  2.2554(10), Dev..     140.70 Sigma
              <I>M<-O1      1.555   1.555                    #         12
PLAT701_ALERT_1_A Bond    Calc  2.0223(11), Rep  2.0339(15), Dev..      10.55 Sigma
              <I>M<-O3      1.555   5.556                    #         13
PLAT701_ALERT_1_A Bond    Calc  4.7859(15), Rep  2.0339(15), Dev..    1834.67 Sigma
              <I>M<-O3      1.555   1.554                    #         14
PLAT701_ALERT_1_A Bond    Calc  2.1147(10), Rep  2.0730(10), Dev..      41.70 Sigma
              <I>M<-O1      1.555   1.555                    #         15
PLAT701_ALERT_1_A Bond    Calc  3.6711(11), Rep  2.0730(10), Dev..    1452.82 Sigma
              <I>M<-O1      1.555   2.555                    #         16
PLAT701_ALERT_1_A Bond    Calc  4.7796(11), Rep  2.0730(10), Dev..    2460.55 Sigma
              <I>M<-O1      1.555   5.555                    #         17
PLAT701_ALERT_1_A Bond    Calc  3.7202(10), Rep  2.0730(10), Dev..    1647.20 Sigma
              <I>M<-O1      1.555   6.555                    #         18
PLAT702_ALERT_1_A Angle   Calc    40.82(2), Rep   101.65(7), Dev..    3041.50 Sigma
              O4   -<I>M<-O4      7.556   1.555   8.454      #         16
PLAT702_ALERT_1_A Angle   Calc    38.73(2), Rep    92.64(4), Dev..    2695.50 Sigma
              O4   -<I>M<-O2      7.556   1.555   1.554      #         17
PLAT702_ALERT_1_A Angle   Calc    38.09(2), Rep    97.47(4), Dev..    2969.00 Sigma
              O4   -<I>M<-O2      8.454   1.555   1.554      #         18
PLAT702_ALERT_1_A Angle   Calc    54.71(4), Rep    97.47(4), Dev..    1069.00 Sigma
              O4   -<I>M<-O2      7.556   1.555   2.556      #         19
PLAT702_ALERT_1_A Angle   Calc    23.62(3), Rep    92.64(4), Dev..    2300.67 Sigma
              O4   -<I>M<-O2      8.454   1.555   2.556      #         20
PLAT702_ALERT_1_A Angle   Calc    61.71(3), Rep   163.97(6), Dev..    3408.67 Sigma
              O2   -<I>M<-O2      1.554   1.555   2.556      #         21
PLAT702_ALERT_1_A Angle   Calc    68.90(2), Rep   166.32(4), Dev..    4871.00 Sigma
              O4   -<I>M<-O1      7.556   1.555   2.555      #         22
PLAT702_ALERT_1_A Angle   Calc    39.76(2), Rep    91.14(4), Dev..    2569.00 Sigma
              O4   -<I>M<-O1      8.454   1.555   2.555      #         23
PLAT702_ALERT_1_A Angle   Calc    36.22(2), Rep    80.77(4), Dev..    2227.50 Sigma
              O2   -<I>M<-O1      1.554   1.555   2.555      #         24
PLAT702_ALERT_1_A Angle   Calc    55.31(3), Rep    86.65(4), Dev..    1044.67 Sigma
              O2   -<I>M<-O1      2.556   1.555   2.555      #         25
PLAT702_ALERT_1_A Angle   Calc    52.81(3), Rep    91.14(4), Dev..    1277.67 Sigma
              O4   -<I>M<-O1      7.556   1.555   1.555      #         26
PLAT702_ALERT_1_A Angle   Calc    62.62(3), Rep   166.32(4), Dev..    3456.67 Sigma
              O4   -<I>M<-O1      8.454   1.555   1.555      #         27
PLAT702_ALERT_1_A Angle   Calc    24.54(3), Rep    86.65(4), Dev..    2070.33 Sigma
              O2   -<I>M<-O1      1.554   1.555   1.555      #         28
PLAT702_ALERT_1_A Angle   Calc    86.24(4), Rep    80.77(4), Dev..     136.75 Sigma
              O2   -<I>M<-O1      2.556   1.555   1.555      #         29
PLAT702_ALERT_1_A Angle   Calc    49.26(3), Rep    76.60(5), Dev..     911.33 Sigma
              O1   -<I>M<-O1      2.555   1.555   1.555      #         30
PLAT702_ALERT_1_A Angle   Calc    57.33(5), Rep   180.00(6), Dev..    2453.40 Sigma
              O3   -<I>M<-O3      5.556   1.555   1.554      #         31
PLAT702_ALERT_1_A Angle   Calc    83.68(5), Rep    84.47(4), Dev..      15.80 Sigma
              O3   -<I>M<-O1      5.556   1.555   1.555      #         32
PLAT702_ALERT_1_A Angle   Calc    26.41(3), Rep    95.53(4), Dev..    2304.00 Sigma
              O3   -<I>M<-O1      1.554   1.555   1.555      #         33
PLAT702_ALERT_1_A Angle   Calc    55.92(4), Rep    95.53(4), Dev..     990.25 Sigma
              O3   -<I>M<-O1      5.556   1.555   2.555      #         34
PLAT702_ALERT_1_A Angle   Calc    35.07(2), Rep    84.47(4), Dev..    2470.00 Sigma
              O3   -<I>M<-O1      1.554   1.555   2.555      #         35
PLAT702_ALERT_1_A Angle   Calc    49.26(3), Rep    84.81(5), Dev..    1185.00 Sigma
              O1   -<I>M<-O1      1.555   1.555   2.555      #         36
PLAT702_ALERT_1_A Angle   Calc    23.81(5), Rep    95.53(4), Dev..    1434.40 Sigma
              O3   -<I>M<-O1      5.556   1.555   5.555      #         37
PLAT702_ALERT_1_A Angle   Calc    33.55(2), Rep    84.47(4), Dev..    2546.00 Sigma
              O3   -<I>M<-O1      1.554   1.555   5.555      #         38
PLAT702_ALERT_1_A Angle   Calc    59.94(3), Rep   180.00(6), Dev..    4002.00 Sigma
              O1   -<I>M<-O1      1.555   1.555   5.555      #         39
PLAT702_ALERT_1_A Angle   Calc    39.83(2), Rep    95.19(5), Dev..    2768.00 Sigma
              O1   -<I>M<-O1      2.555   1.555   5.555      #         40
PLAT702_ALERT_1_A Angle   Calc    46.75(4), Rep    84.47(4), Dev..     943.00 Sigma
              O3   -<I>M<-O1      5.556   1.555   6.555      #         41
PLAT702_ALERT_1_A Angle   Calc    39.45(2), Rep    95.53(4), Dev..    2804.00 Sigma
              O3   -<I>M<-O1      1.554   1.555   6.555      #         42
PLAT702_ALERT_1_A Angle   Calc    55.38(3), Rep    95.19(5), Dev..    1327.00 Sigma
              O1   -<I>M<-O1      1.555   1.555   6.555      #         43
PLAT702_ALERT_1_A Angle   Calc    68.24(2), Rep   180.00(3), Dev..    5588.00 Sigma
              O1   -<I>M<-O1      2.555   1.555   6.555      #         44
PLAT702_ALERT_1_A Angle   Calc    35.73(2), Rep    84.81(5), Dev..    2454.00 Sigma
              O1   -<I>M<-O1      5.555   1.555   6.555      #         45
PLAT924_ALERT_1_A The Reported and Calculated Rho(min) Differ by .      27.59 eA-3
PLAT925_ALERT_1_A The Reported and Calculated Rho(max) Differ by .       3.05 eA-3
PLAT926_ALERT_1_A Reported and Calculated   R1 * 100.0 Differ by .     -17.35
PLAT927_ALERT_1_A Reported and Calculated  wR2 * 100.0 Differ by .     -43.30
PLAT928_ALERT_1_A Reported and Calculated    S value   Differ by .      -6.70

Alert level B
PLAT232_ALERT_2_B Hirshfeld Test Diff (M-X)  Mn1#   --  O2      ..      20.50 su
PLAT232_ALERT_2_B Hirshfeld Test Diff (M-X)  M4C    --  O2      ..      21.01 su

Alert level C
PLAT220_ALERT_2_C Large Non-Solvent   Mn     Ueq(max)/Ueq(min) ...       3.22 Ratio
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Mn1#   --  O1      ..       9.09 su
PLAT232_ALERT_2_C Hirshfeld Test Diff (M-X)  Mn1#   --  O3      ..       8.34 su
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          1
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          4
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       2.50 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.66 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.53 eA-3
PLAT971_ALERT_2_C Large Calcd. Non-Metal Positive Residual Density       1.53 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -2.40 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.87 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.74 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.66 eA-3
PLAT972_ALERT_2_C Large Calcd. Non-Metal Negative Residual Density      -1.51 eA-3
PLAT041_ALERT_1_C Calc. and Reported SumFormula    Strings  Differ          ?
PLAT043_ALERT_1_C Check Reported Molecular Weight ................     897.29
PLAT044_ALERT_1_C Calculated and Reported Dx Differ ..............          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       0.50 Ratio
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)...          ?
PLAT077_ALERT_4_C Unitcell contains non-integer number of atoms ..          ?
PLAT224_ALERT_1_C Ueq(Rep) and Ueq(Calc) differ by  0.003 Ang   2 .        Mn1#     
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         19

Alert level G
FORMU01_ALERT_2_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and the formula from the _atom_site* data.
            Atom count from _chemical_formula_sum:H1.86 Al0.2 Ca0.18 F0.14 Fe0.2
            Atom count from the _atom_site data:  Ca0.18 K0.208 Mg2.3062 Mn2.913
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G ALERT: Large difference may be due to a
            symmetry error - see SYMMG tests
           From the CIF: _cell_formula_units_Z    2
           From the CIF: _chemical_formula_sum  Al.2 Ca.18 F.14 Fe.27 H1.86 K.2
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           Al         0.40      0.00    0.40
           Ca         0.36      0.36    0.00
           F          0.28      0.00    0.28
           Fe         0.54      0.00    0.54
           H          3.72      0.00    3.72
           K          0.40      0.42   -0.02
           Mg         4.40      4.61   -0.21
           Mn         5.22      5.83   -0.61
           Na         4.80      4.65    0.15
           O         47.72     48.00   -0.28
           Si        15.84     16.00   -0.16
           Ti         0.04      0.00    0.04
PLAT301_ALERT_3_G Note: Main Residue  Disorder ...................      13.00 Perc.
PLAT396_ALERT_2_G Deviating Si-O-Si Angle from 150 Deg for      O5     137.20 Deg.
PLAT396_ALERT_2_G Deviating Si-O-Si Angle from 150 Deg for      O6     137.00 Deg.
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          1
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K
PLAT302_ALERT_4_G Note: Anion/Solvent Disorder ...................      16.00 Perc.
PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels ..........         12
PLAT793_ALERT_4_G The Model has Chirality at Si1     (Verify) ....          S
PLAT793_ALERT_4_G The Model has Chirality at Si2     (Verify) ....          S
PLAT811_ALERT_5_G No ADDSYM Analysis: Too Many Excluded Atoms ....          !

  58 ALERT level A = In general: serious problem
   2 ALERT level B = Potentially serious problem
  22 ALERT level C = Check and explain
  14 ALERT level G = General alerts; check

  62 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
  23 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   6 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

---

S1. Comment

Kôzulite, with the ideal formula NaNa₂[Mn₄²⁺(Fe³⁺,Al)]Si₈O₂₂(OH)₂, is an Mn-rich alkali member of the rock-forming amphibole family and was first described by Nambu et al. (1969). Kitamura and Morimoto (1972), in a meeting abstract, presented the structure refinement of a kôzulite crystal with the composition (Na_2.54K_0.27Ca_0.19)(Mn_3.69Mg_0.63Fe³⁺_0.33Al³⁺_0.31)Σi_8.00O_21.78[(OH)_2.18F_0.04]. However, they did not report its detailed structure information, such as atomic coordinates and displacement parameters. This study presents the first reported structure of kôzulite based on single-crystal X-ray diffraction data, as a part of our effort to build an integrated, web-based database of Raman spectra, X-ray diffraction, and chemistry data for all minerals (http://rruff.info).

The site occupancies determined from the refinements are M1 = 0.453 (1) Mn + 0.547 (1) Mg, M2 = 0.766 (1) Mn + 0.234 (1) Mg, and M3 = 0.257 (1) Mn + 0.743 (1) Mg, where Mn and Mg represent (Mn +Fe) and (Mg + Al), respectively. There results should be compared to those given by Kitamura and Morimoto (1972) for their kôzulite crystal: M1 = 0.78 Mn + 0.22 Mg, M2 = 0.95 Mn + 0.05 Mg, and M3 = 0.58 Mn + 0.42 Mg. The average M—O bond lengths are 2.064 (1), 2.139 (1), and 2.060 (1) Å for the M1, M2, and M3 sites, respectively. These values indicate that the M2 site is dominantly occupied by larger Mn²⁺, whereas the M1 and M3 sites should have similar amounts of (Mn³⁺ + Fe³⁺) and Mg. The relatively short average M3—O distance (versus. M1—O) suggests that Al³⁺ is preferentially ordered into the M3 site. Our results on kôzulite are very similar to those observed by Hawthorne et al. (1995) for ungarettiite with the composition (K_0.15Na_0.82)(Na_1.97Ca_0.03)˘Mn²⁺_1.66Mn³⁺_2.97Mg_0.34Fe³⁺_0.03Zn_0.01)(Si_7.99Al_0.01)O₂₂O_2. The average M—O distances in ungarettiite are 2.03, 2.17, and 2.01 Å for the M1, M2, and M3 sites, respectively, pointing to the strong ordering of larger Mn²⁺ into the M2 site and smaller Mn³⁺ into M1 and M3.

Four partially occupied amphibole A sites [A(m), A(m)', A(2), and A(1)] were revealed from the structure refinements. The refinement shows that K prefers the A(m) site, whereas Na is distributed among the other three sites. The refined A site occupancies are 0.208 K + 0.764Na [A(m) = 0.208 (4) K, A(m)' = 0.374 (14) Na, A(2) = 0.146 (6)Na, and A(1) = 0.224 (18) Na], consistent with the result derived from microprobe analysis (0.20 K + 0.80Na), considering experimental uncertainties. The presence of two distinct A sites on the mirror plane, A(m) and A(m)' has also been observed in many other alkali amphiboles (e.g., Hawthorne et al. 1996; Hawthorne and Harlow 2008).

Related literature

For more information on the geologic occurrence of kôzulite, see: Ashley (1986); Banno (1997); Hirtopanu (2006); Kawachi & Coombs (1993); Matsubara et al. (2002); Nambu et al. (1969, 1970, 1981); Watanabe et al. (1976). For the initial structural refinement of kôzulite, see: Fleischer & Nickel (1970); Kitamura & Morimoto (1972). For general background to the amphibole group, see: Hawthorne (1983); Hawthorne et al. (1995, 1996); Hawthorne & Harlow (2008).For background information on the amphibole group and nomenclature, see: Leake (1978); Leake et al. (1997, 2003); Mogessie et al. (2004).

S2. Experimental

The kôzulite specimen used in this study is from the type locality Tanohata Mine, Iwate Prefecture, Tohoku Region, Honshu Island, Japan and is in the collection of the RRUFF project (deposition No. R070122; http://rruff.info). The crystal chemistry was determined with a CAMECA SX50 electron microprobe (http://rruff.info) on the same single-crystal used for the collection of X-ray intensity data. The average composition (10 point analyses) yielded a chemical formula (normalized on the basis of 23 oxygen): (K_0.20Na_0.80)(Na_1.60Ca_0.18Mn²⁺_0.22)˘Mn²⁺_2.14Mn³⁺_0.25Mg_2.20Fe³⁺_0.27Al_0.14)˘Si_7.92Al_0.06Ti_0.02)O₂₂[(OH)_1.86F_0.14].

S3. Refinement

The chemical analysis and crystal-chemical considerations show that the C-group cations consist of Mn²⁺, Mn³⁺, Fe³⁺, Mg, and Al³⁺. Because of similar X-ray scattering powers, Fe and Mn were grouped together (represented by the scattering factor for Mn) and Mg and Al together (represented by Mg) throughout the structure refinements. No refinement was made for the cations in the M4 site (= Na_0.80Ca_0.09Mn²⁺_0.11); they were assigned based on crystal-chemical considerations and previous studies on amphiboles (Hawthorne 1983). The total Mn and Mg in the M1 + M2 + M3 sites were fixed to those from the chemical analysis. To dampen the extreme correlations that would otherwise occur among the refined A-site variables, the isotropic displacement factors of these A sites were constrained to be equal (Hawthorne & Harlow 2008).

Computing details

Data collection: APEX2 (Bruker, 2003); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008b); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008b); molecular graphics: XtalDraw (Downs & Hall-Wallace, 2003); software used to prepare material for publication: SHELXTL (Sheldrick, 2008b).

Figures

Fig. 1. The crystal structure of kôzulite. Green and yellow tetrahedra represent [Si1O4] and [Si2O4] groups, respectively. Purple, blue, and red octahedra represent the M1, M2, and M3 octahedra, respectively. The small blue and large pink spheres represent the M4 and A cations, respectively.

trisodium tetramanganese iron/aluminium octasilicate dihydroxide

Crystal data

Na3[Mn4(Fe)]Si8O22(OH)2	F(000) = 954
Mr = 897.29	Dx = 3.232 Mg m^−3
Monoclinic, C2/m	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2y	Cell parameters from 2537 reflections
a = 9.9024 (7) Å	θ = 4.0–34.7°
b = 18.1117 (12) Å	µ = 2.87 mm^−1
c = 5.2992 (4) Å	T = 293 K
β = 104.034 (4)°	Euhedral, brown
V = 922.04 (11) Å^3	0.06 × 0.05 × 0.04 mm
Z = 2

Data collection

Bruker APEXII CCD area-detector diffractometer	1977 independent reflections
Radiation source: fine-focus sealed tube	1656 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.019
φ and ω scans	θmax = 34.4°, θmin = 2.4°
Absorption correction: multi-scan (SADABS; Sheldrick, 2008a)	h = −15→15
Tmin = 0.847, Tmax = 0.894	k = −28→28
7829 measured reflections	l = −8→7

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.023	H-atom parameters not refined
wR(F^2) = 0.067	w = 1/[σ^2(Fo^2) + (0.0302P)^2 + 1.2008P] where P = (Fo^2 + 2Fc^2)/3
S = 1.08	(Δ/σ)max < 0.001
1977 reflections	Δρmax = 0.58 e Å^−3
111 parameters	Δρmin = −0.59 e Å^−3
1 restraint

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq	Occ. (<1)
M1	0.0000	0.08447 (2)	0.5000	0.00933 (11)	0.4529 (19)
M1A	0.0000	0.08447 (2)	0.5000	0.00933 (11)	0.5471 (19)
M2	0.0000	0.182241 (18)	0.0000	0.00935 (9)	0.766 (2)
M2A	0.0000	0.182241 (18)	0.0000	0.00935 (9)	0.234 (2)
M3	0.0000	0.0000	0.0000	0.00682 (19)	0.256 (4)
M3A	0.0000	0.0000	0.0000	0.00682 (19)	0.744 (4)
M4A	0.0000	0.27152 (4)	0.5000	0.02191 (15)	0.79
M4B	0.0000	0.27152 (4)	0.5000	0.02191 (15)	0.09
M4C	0.0000	0.27152 (4)	0.5000	0.02191 (15)	0.11
Si1	0.28233 (4)	0.084285 (19)	0.28706 (7)	0.00858 (8)
Si2	0.28734 (4)	0.16909 (2)	0.79054 (7)	0.00908 (8)
O1	0.11555 (10)	0.08452 (5)	0.2127 (2)	0.01077 (18)
O2	0.11918 (11)	0.16575 (6)	0.7170 (2)	0.01460 (19)
O3	0.10330 (15)	0.0000	0.7118 (3)	0.0131 (3)
O4	0.35819 (12)	0.24732 (6)	0.7901 (2)	0.0179 (2)
O5	0.34710 (10)	0.12714 (6)	0.0742 (2)	0.01335 (19)
O6	0.34473 (10)	0.11704 (6)	0.57692 (19)	0.01358 (19)
O7	0.34279 (16)	0.0000	0.2884 (3)	0.0154 (3)
AM	0.5211 (9)	0.0000	0.053 (2)	0.0149 (9)*	0.104 (4)
AM'	0.5562 (10)	0.0000	0.1298 (17)	0.0149 (9)*	0.187 (11)
A2	0.5000	−0.0215 (15)	0.0000	0.0149 (9)*	0.073 (6)
A1	0.5386 (18)	−0.0192 (18)	0.103 (4)	0.0149 (9)*	0.056 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
M1	0.00812 (19)	0.01278 (19)	0.00693 (19)	0.000	0.00151 (14)	0.000
M1A	0.00812 (19)	0.01278 (19)	0.00693 (19)	0.000	0.00151 (14)	0.000
M2	0.00981 (15)	0.00801 (14)	0.01081 (16)	0.000	0.00360 (11)	0.000
M2A	0.00981 (15)	0.00801 (14)	0.01081 (16)	0.000	0.00360 (11)	0.000
M3	0.0078 (3)	0.0059 (3)	0.0063 (3)	0.000	0.0009 (2)	0.000
M3A	0.0078 (3)	0.0059 (3)	0.0063 (3)	0.000	0.0009 (2)	0.000
M4A	0.0226 (4)	0.0251 (4)	0.0224 (4)	0.000	0.0139 (3)	0.000
M4B	0.0226 (4)	0.0251 (4)	0.0224 (4)	0.000	0.0139 (3)	0.000
M4C	0.0226 (4)	0.0251 (4)	0.0224 (4)	0.000	0.0139 (3)	0.000
Si1	0.00867 (16)	0.00776 (15)	0.00854 (16)	−0.00068 (11)	0.00063 (12)	0.00007 (11)
Si2	0.00895 (16)	0.00906 (15)	0.00918 (16)	−0.00125 (11)	0.00213 (12)	0.00087 (11)
O1	0.0088 (4)	0.0112 (4)	0.0115 (4)	−0.0013 (3)	0.0009 (3)	−0.0005 (3)
O2	0.0093 (4)	0.0202 (5)	0.0138 (5)	0.0015 (4)	0.0018 (3)	0.0031 (4)
O3	0.0139 (6)	0.0114 (6)	0.0133 (6)	0.000	0.0021 (5)	0.000
O4	0.0236 (5)	0.0115 (4)	0.0186 (5)	−0.0056 (4)	0.0054 (4)	0.0012 (4)
O5	0.0112 (4)	0.0171 (5)	0.0114 (4)	0.0000 (3)	0.0021 (3)	0.0049 (3)
O6	0.0115 (4)	0.0184 (5)	0.0099 (4)	0.0004 (3)	0.0006 (3)	−0.0039 (3)
O7	0.0149 (7)	0.0076 (5)	0.0227 (7)	0.000	0.0022 (5)	0.000

Geometric parameters (Å, º)

M1—O3^i	2.0223 (10)	M4A—O5^ix	3.0160 (12)
M1—O3	2.0223 (10)	Si1—O1	1.6022 (11)
M1—O2	2.0551 (11)	Si1—O6	1.6226 (11)
M1—O2^ii	2.0551 (11)	Si1—O5	1.6240 (10)
M1—O1	2.1148 (10)	Si1—O7	1.6391 (7)
M1—O1^ii	2.1148 (10)	Si2—O4	1.5814 (11)
M2—O4^iii	2.0197 (11)	Si2—O2	1.6166 (11)
M2—O4^iv	2.0197 (11)	Si2—O5^x	1.6598 (11)
M2—O2^v	2.1425 (11)	Si2—O6	1.6748 (11)
M2—O2^ii	2.1425 (11)	AM—O7^xi	2.506 (7)
M2—O1^vi	2.2554 (10)	AM—O5^xii	2.809 (3)
M2—O1	2.2554 (10)	AM—O5^xi	2.809 (3)
M3—O3^i	2.0339 (15)	AM—O5^viii	2.894 (4)
M3—O3^v	2.0339 (15)	AM'—O7^xi	2.643 (7)
M3—O1	2.0730 (10)	AM'—O6^xiii	2.671 (6)
M3—O1^vi	2.0730 (10)	AM'—O6^xiv	2.671 (6)
M3—O1^vii	2.0730 (10)	AM'—O5^xii	2.809 (4)
M3—O1^viii	2.0730 (10)	A2—O7^xi	2.463 (4)
M4A—O4^ix	2.3450 (12)	A2—O5^viii	2.53 (2)
M4A—O4^iii	2.3450 (12)	A2—O5^xi	2.53 (2)
M4A—O2^ii	2.3930 (13)	A1—O6^xiv	2.53 (3)
M4A—O2	2.3930 (13)	A1—O5^xi	2.55 (3)
M4A—O6^iii	2.6283 (12)	A1—O7^xi	2.644 (17)
M4A—O6^ix	2.6283 (12)	A1—O5^viii	2.70 (3)
M4A—O5^iii	3.0160 (12)
O3^i—M1—O3	81.68 (6)	O1^vi—M2—O1	76.60 (5)
O3^i—M1—O2	175.50 (5)	O3^i—M3—O3^v	180.00 (6)
O3—M1—O2	94.98 (4)	O3^i—M3—O1	84.47 (4)
O3^i—M1—O2^ii	94.98 (4)	O3^v—M3—O1	95.53 (4)
O3—M1—O2^ii	175.50 (5)	O3^i—M3—O1^vi	95.53 (4)
O2—M1—O2^ii	88.50 (6)	O3^v—M3—O1^vi	84.47 (4)
O3^i—M1—O1	83.68 (5)	O1—M3—O1^vi	84.81 (5)
O3—M1—O1	96.35 (5)	O3^i—M3—O1^vii	95.53 (4)
O2—M1—O1	93.72 (4)	O3^v—M3—O1^vii	84.47 (4)
O2^ii—M1—O1	86.24 (4)	O1—M3—O1^vii	180.00 (6)
O3^i—M1—O1^ii	96.35 (5)	O1^vi—M3—O1^vii	95.19 (5)
O3—M1—O1^ii	83.68 (5)	O3^i—M3—O1^viii	84.47 (4)
O2—M1—O1^ii	86.24 (4)	O3^v—M3—O1^viii	95.53 (4)
O2^ii—M1—O1^ii	93.72 (4)	O1—M3—O1^viii	95.19 (5)
O1—M1—O1^ii	179.95 (6)	O1^vi—M3—O1^viii	180.00 (3)
O4^iii—M2—O4^iv	101.65 (7)	O1^vii—M3—O1^viii	84.81 (5)
O4^iii—M2—O2^v	92.64 (4)	O1—Si1—O6	111.41 (5)
O4^iv—M2—O2^v	97.47 (4)	O1—Si1—O5	112.64 (5)
O4^iii—M2—O2^ii	97.47 (4)	O6—Si1—O5	111.04 (6)
O4^iv—M2—O2^ii	92.64 (4)	O1—Si1—O7	110.92 (6)
O2^v—M2—O2^ii	163.97 (6)	O6—Si1—O7	106.35 (7)
O4^iii—M2—O1^vi	166.32 (4)	O5—Si1—O7	104.05 (7)
O4^iv—M2—O1^vi	91.14 (4)	O4—Si2—O2	117.68 (6)
O2^v—M2—O1^vi	80.77 (4)	O4—Si2—O5^x	110.52 (6)
O2^ii—M2—O1^vi	86.65 (4)	O2—Si2—O5^x	108.75 (6)
O4^iii—M2—O1	91.14 (4)	O4—Si2—O6	106.26 (6)
O4^iv—M2—O1	166.32 (4)	O2—Si2—O6	108.33 (6)
O2^v—M2—O1	86.65 (4)	O5^x—Si2—O6	104.45 (6)
O2^ii—M2—O1	80.77 (4)

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