Download citation
Download citation
link to html
The two-dimensional network topology of the mixed alkali title compound, K1.33Na0.67Si2O5, is found to differ from that of the end-member compositions, Na2Si2O5 and K2Si2O5. The network of the silicate sheet consists of rings with four, six and eight SiO4 tetra­hedra. The cations are sandwiched between the silicate sheets.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536805022348/br6203sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536805022348/br6203Isup2.hkl
Contains datablock I

Key indicators

  • Single-crystal X-ray study
  • T = 150 K
  • Mean [sigma](i-O) = 0.004 Å
  • R factor = 0.043
  • wR factor = 0.118
  • Data-to-parameter ratio = 11.4

checkCIF/PLATON results

No syntax errors found



Alert level C ABSTM02_ALERT_3_C The ratio of Tmax/Tmin expected RT(exp) is > 1.10 Absorption corrections should be applied. Tmin and Tmax expected: 0.609 0.711 RT(exp) = 1.167 PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .... ? PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ? PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............ 0.33 Ratio PLAT057_ALERT_3_C Correction for Absorption Required RT(exp) ... 1.17 PLAT213_ALERT_2_C Atom O22 has ADP max/min Ratio ............. 3.10 prolat PLAT213_ALERT_2_C Atom O23 has ADP max/min Ratio ............. 3.60 prolat PLAT220_ALERT_2_C Large Non-Solvent O Ueq(max)/Ueq(min) ... 2.96 Ratio PLAT242_ALERT_2_C Check Low Ueq as Compared to Neighbors for Si2 PLAT396_ALERT_2_C Deviating Si-O-Si Angle from 150 Deg for O23 165.10 Deg.
Alert level G CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected. CELLZ01_ALERT_1_G ALERT: check formula stoichiometry or atom site occupancies. From the CIF: _cell_formula_units_Z 12 From the CIF: _chemical_formula_sum K1.33 Na0.67 O5 Si2 TEST: Compare cell contents of formula and atom_site data atom Z*formula cif sites diff K 15.96 16.00 -0.04 Na 8.04 8.00 0.04 O 60.00 60.00 0.00 Si 24.00 24.00 0.00
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 10 ALERT level C = Check and explain 2 ALERT level G = General alerts; check 5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 5 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 0 ALERT type 4 Improvement, methodology, query or suggestion

Computing details top

Data collection: locally modified CAD-4 Software (Enraf–Nonius, 1989); cell refinement: SET4 (de Boer & Duisenberg, 1984); data reduction: HELENA (Spek, 1997); program(s) used to solve structure: DIRDIF99 (Beurskens et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: PLATON.

Potassium sodium phyllosilicate top
Crystal data top
K1.33Na0.67Si2O5F(000) = 1208
Mr = 203.64Least Squares Treatment of 25 SET4 setting angles.
Monoclinic, C2/cDx = 2.552 Mg m3
Hall symbol: -C 2ycMo Kα radiation, λ = 0.71073 Å
a = 19.6816 (15) ÅCell parameters from 9 reflections
b = 7.2656 (6) Åθ = 10–14°
c = 12.5710 (15) ŵ = 1.71 mm1
β = 117.82 (1)°T = 150 K
V = 1589.9 (3) Å3Block, colorless
Z = 120.3 × 0.3 × 0.2 mm
Data collection top
Enraf–Nonius TurboCAD-4
diffractometer
Rint = 0.068
Radiation source: Rotating Anodeθmax = 25°, θmin = 2.3°
Graphite monochromatorh = 238
ω scansk = 88
2841 measured reflectionsl = 1314
1406 independent reflections1 standard reflections every 60 min
1094 reflections with I > 2σ(I) intensity decay: none
Refinement top
Refinement on F26 restraints
Least-squares matrix: fullPrimary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.043Secondary atom site location: difference Fourier map
wR(F2) = 0.118 w = 1/[σ2(Fo2) + (0.0465P)2 + 11.2001P]
where P = (Fo2 + 2Fc2)/3
S = 1.09(Δ/σ)max = 0.001
1406 reflectionsΔρmax = 0.65 e Å3
123 parametersΔρmin = 0.92 e Å3
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

Refinement. Refinement on F2 for ALL reflections except those flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The observed criterion of F2 > σ(F2) is used only for calculating -R-factor-obs 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
xyzUiso*/Ueq
Si10.15093 (8)0.3950 (2)0.00188 (12)0.0083 (4)
Si20.06654 (8)0.7460 (2)0.11486 (12)0.0085 (4)
Si30.32560 (8)0.4508 (2)0.11444 (14)0.0131 (4)
O110.1430 (2)0.3936 (6)0.1196 (3)0.0219 (12)
O120.2340 (2)0.4647 (5)0.0170 (3)0.0162 (12)
O130.1349 (2)0.1899 (6)0.0584 (4)0.0181 (12)
O140.0870 (2)0.5250 (5)0.1061 (3)0.0114 (10)
O210.0425 (3)0.8137 (6)0.0203 (4)0.0303 (14)
O220.1441 (2)0.8450 (6)0.1007 (5)0.0338 (16)
O230.000000.7746 (8)0.250000.0305 (17)
O310.3418 (2)0.4068 (7)0.2448 (3)0.0311 (14)
K10.06258 (9)0.6274 (2)0.16520 (13)0.0293 (5)
K20.25138 (8)0.3240 (2)0.33695 (11)0.0246 (4)
Na10.08060 (13)0.0864 (3)0.09417 (19)0.0209 (7)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Si10.0097 (7)0.0067 (7)0.0070 (7)0.0008 (6)0.0027 (6)0.0011 (6)
Si20.0094 (7)0.0073 (7)0.0051 (7)0.0010 (6)0.0003 (6)0.0002 (6)
Si30.0097 (8)0.0075 (7)0.0180 (8)0.0008 (6)0.0030 (6)0.0026 (6)
O110.026 (2)0.027 (2)0.015 (2)0.005 (2)0.0116 (18)0.0052 (18)
O120.014 (2)0.012 (2)0.020 (2)0.0015 (17)0.0057 (17)0.0082 (17)
O130.016 (2)0.011 (2)0.028 (2)0.0030 (17)0.0109 (18)0.0073 (18)
O140.0137 (19)0.0085 (18)0.0078 (17)0.0016 (16)0.0014 (15)0.0005 (15)
O210.060 (3)0.023 (2)0.022 (2)0.017 (2)0.031 (2)0.009 (2)
O220.017 (2)0.010 (2)0.074 (4)0.0042 (18)0.021 (2)0.009 (2)
O230.039 (3)0.012 (3)0.012 (3)0.00000.012 (2)0.0000
O310.018 (2)0.056 (3)0.011 (2)0.007 (2)0.0003 (18)0.008 (2)
K10.0291 (8)0.0260 (8)0.0241 (8)0.0036 (6)0.0052 (6)0.0052 (6)
K20.0325 (8)0.0325 (8)0.0125 (6)0.0087 (6)0.0136 (6)0.0084 (6)
Na10.0224 (13)0.0163 (12)0.0138 (11)0.0039 (10)0.0000 (9)0.0042 (9)
Geometric parameters (Å, º) top
Si1—O111.559 (4)K1—O14iv2.904 (4)
Si1—O121.636 (5)K1—O13iv3.353 (5)
Si1—O131.634 (5)K1—O31v2.637 (5)
Si1—O141.650 (4)K2—O112.614 (4)
Si2—O141.647 (4)K2—O312.607 (5)
Si2—O211.550 (6)K2—O12iv2.884 (4)
Si2—O221.620 (5)K2—O22iv2.850 (5)
Si2—O231.6024 (16)K2—O22vi2.980 (6)
Si3—O121.643 (4)K2—O12vi3.127 (4)
Si3—O311.550 (4)Na1—O112.495 (5)
Si3—O13i1.630 (5)Na1—O132.702 (5)
Si3—O22ii1.638 (5)Na1—O21vii2.356 (5)
K1—O112.563 (5)Na1—O21iii2.271 (7)
K1—O212.562 (5)Na1—O31vi2.291 (5)
K1—O14iii2.899 (5)
O11—Si1—O12115.4 (2)O12—Si3—O31114.4 (2)
O11—Si1—O13110.6 (2)O12—Si3—O13i107.2 (2)
O11—Si1—O14114.1 (2)O12—Si3—O22ii101.1 (2)
O12—Si1—O13107.6 (2)O13i—Si3—O31115.1 (3)
O12—Si1—O14104.8 (2)O22ii—Si3—O31113.1 (3)
O13—Si1—O14103.4 (2)O13i—Si3—O22ii104.6 (3)
O14—Si2—O21114.3 (2)Si1—O12—Si3139.2 (2)
O14—Si2—O22103.7 (2)Si1—O13—Si3i138.1 (3)
O14—Si2—O23104.5 (2)Si1—O14—Si2133.0 (2)
O21—Si2—O22112.6 (3)Si2—O22—Si3ii139.6 (3)
O21—Si2—O23112.4 (2)Si2—O23—Si2viii165.1 (4)
O22—Si2—O23108.7 (2)
Symmetry codes: (i) x+1/2, y+1/2, z; (ii) x+1/2, y+3/2, z; (iii) x, y+1, z; (iv) x, y+1, z+1/2; (v) x+1/2, y+1/2, z+1/2; (vi) x+1/2, y1/2, z+1/2; (vii) x, y1, z; (viii) x, y, z1/2.
 

Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds