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Potassium calcium fluoride carbonate, KCaF(CO3), has been synthesized and its structure solved from X-ray powder diffraction data. The K, Ca, F and C atoms lie at sites with {\overline6}m2 imposed symmetry and the unique O atom has imposed mm site symmetry. The compound consists of Ca-F-Ca chains parallel to the c axis and planar CO3 groups perpendicular to the c axis, the corners of the hexagonal cell being occupied by K+ ions. The compound is not a solid solution, since the structure differs from those of both KF and CaCO3.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536804005069/wn6225sup1.cif
Contains datablocks kcafo, I

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600536804005069/wn6225Isup2.rtv
Contains datablock I

Key indicators

  • Powder X-ray study
  • T = 295 K
  • Mean [sigma](O-C) = 0.002 Å
  • R factor = 0.000
  • wR factor = 0.000
  • Data-to-parameter ratio = 0.0

checkCIF/PLATON results

No syntax errors found



Alert level A WEIGH01_ALERT_1_A The weighting scheme should be one of the following * sigma * calc Weighting scheme given as 1/Y~i~
Author Response: for pwoder data refinement, 1/y~i~ is usually used as the weight
PLAT025_ALERT_1_A Hmin..Lmax Data Incomplete or Missing ..........          ?
Author Response: for pwoder data, this is not applicable
PLAT027_ALERT_3_A _diffrn_reflns_theta_full (too) Low ............       0.00 Deg.
Author Response: for pwoder data, this is not applicable.
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.00
Author Response: for pwoder data, this is not applicable
PLAT050_ALERT_1_A Absorption Coefficient mu Missing ..............          ?
Author Response: For reflection data collecting mode, mu can not be considered since it is a constant for all diffraction angles.

Alert level C CELLV02_ALERT_1_C The supplied cell volume s.u. differs from that calculated from the cell parameter s.u.'s by > 2 Calculated cell volume su = 2.51 Cell volume su given = 5.00 RADNW01_ALERT_1_C The radiation wavelength lies outside the expected range for the supplied radiation type. Expected range 1.54175-1.54180 Wavelength given = 1.54439 PLAT034_ALERT_1_C No Flack Parameter Given. Z .GT. Si, NonCentro . ? PLAT040_ALERT_1_C No H-atoms in this Carbon Containing Compound .. ? PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ .... ? PLAT087_ALERT_2_C Unsatisfactory S value (Too High) .............. 2.26 PLAT430_ALERT_2_C Short Inter D...A Contact O .. O .. 2.88 Ang. PLAT430_ALERT_2_C Short Inter D...A Contact O .. O .. 2.88 Ang.
Alert level G RADNT01_ALERT_1_G Extra text has been found in the _diffrn_radiation_type field. Radiation given as CuK\a~1~ CuK\a~2~ Radiation identified as Cu K\a
5 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 8 ALERT level C = Check and explain 1 ALERT level G = General alerts; check 9 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 3 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: Rint2400 (Rigaku Corporation, 1993); cell refinement: Highscore1.0b (Philips Electronics, 2002); data reduction: Highscore1.0b (Philips Electronics, 2002); program(s) used to solve structure: SHEXLS97 (Sheldrick, 1997); program(s) used to refine structure: FULLPROF (Rodriguez-Carvajal, 2003); molecular graphics: Balls & Sticks (Kang & Ozawa, 2003).

potassium calcium flurine-carbonate top
Crystal data top
KCaF(CO3)Dx = 2.615 Mg m3
Mr = 158.17Melting point: 774.0 K
Hexagonal, P6m2CuKα1, CuKα2 radiation, λ = 1.540562, 1.544390 Å
Hall symbol: P -6 2T = 295 K
a = 5.10093 (7) ÅParticle morphology: plate-like
c = 4.45510 (7) Åwhite
V = 100.39 (1) Å3flat_sheet, 15 × 35 mm
Z = 1Specimen preparation: Prepared at 873 K
F(000) = 78
Data collection top
Rint2400
diffractometer
Data collection mode: reflection
Radiation source: rotating-anode x-ray tubeScan method: step
Curved graphite monochromator2θmin = 10°, 2θmax = 135°, 2θstep = 0.02°
Specimen mounting: packed powder pellet
Refinement top
Refinement on InetProfile function: pseudo-Voigt
Least-squares matrix: full with fixed elements per cycle26 parameters
Rp = 0.0801/Yi
Rwp = 0.128(Δ/σ)max = 0.01
Rexp = 0.056Background function: square polynomial for each range
6251 data pointsPreferred orientation correction: Icorr = Iobs[G2+(1-G2)exp(G1a2)], axis (001), (March, 1932)
Excluded region(s): none
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
K0000.0126 (6)*
C0.666670.333330.50.018 (2)*
Ca0.333330.666670.50.0100 (6)*
O0.8120 (3)0.1880 (3)0.50.0129*
F0.333330.6666700.0196 (1)*
Geometric parameters (Å, º) top
K—Oi2.779 (1)C—Oix1.284 (1)
K—Oii2.779 (1)C—Ovi1.284 (1)
K—Oiii2.779 (1)Ca—Oii2.557 (1)
K—Oiv2.779 (1)Ca—Ox2.557 (1)
K—Ov2.779 (1)Ca—Oxi2.557 (1)
K—Ovi2.779 (1)Ca—Oix2.557 (1)
K—Fvii2.9450 (1)Ca—Ovi2.557 (1)
K—Fviii2.9450 (1)Ca—Oxii2.557 (1)
K—F2.9450 (1)Ca—F2.2275 (1)
C—O1.284 (1)Ca—Fxiii2.2275 (1)
O—C—Oix120Oix—C—Ovi120
O—C—Ovi120
Symmetry codes: (i) x1, y, z1; (ii) x1, y, z; (iii) y, xy1, z1; (iv) y, xy1, z; (v) x+y+1, x+1, z1; (vi) x+y+1, x+1, z; (vii) x1, y1, z; (viii) x, y1, z; (ix) y+1, xy, z; (x) x, y+1, z; (xi) y, xy, z; (xii) x+y+1, x+2, z; (xiii) x, y, z+1.
 

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