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Potassium calcium fluoride carbonate, KCaF(CO
3), has been synthesized and its structure solved from X-ray powder diffraction data. The K, Ca, F and C atoms lie at sites with
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 CO
3 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 CaCO
3.
Supporting information
Key indicators
- Powder X-ray study
- T = 295 K
- Mean (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
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 m−3 |
Mr = 158.17 | Melting point: 774.0 K |
Hexagonal, P6m2 | CuKα1, CuKα2 radiation, λ = 1.540562, 1.544390 Å |
Hall symbol: P -6 2 | T = 295 K |
a = 5.10093 (7) Å | Particle morphology: plate-like |
c = 4.45510 (7) Å | white |
V = 100.39 (1) Å3 | flat_sheet, 15 × 35 mm |
Z = 1 | Specimen preparation: Prepared at 873 K |
F(000) = 78 | |
Data collection top
Rint2400 diffractometer | Data collection mode: reflection |
Radiation source: rotating-anode x-ray tube | Scan method: step |
Curved graphite monochromator | 2θmin = 10°, 2θmax = 135°, 2θstep = 0.02° |
Specimen mounting: packed powder pellet | |
Refinement top
Refinement on Inet | Profile function: pseudo-Voigt |
Least-squares matrix: full with fixed elements per cycle | 26 parameters |
Rp = 0.080 | 1/Yi |
Rwp = 0.128 | (Δ/σ)max = 0.01 |
Rexp = 0.056 | Background function: square polynomial for each range |
6251 data points | Preferred 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 | x | y | z | Uiso*/Ueq | |
K | 0 | 0 | 0 | 0.0126 (6)* | |
C | 0.66667 | 0.33333 | 0.5 | 0.018 (2)* | |
Ca | 0.33333 | 0.66667 | 0.5 | 0.0100 (6)* | |
O | 0.8120 (3) | 0.1880 (3) | 0.5 | 0.0129* | |
F | 0.33333 | 0.66667 | 0 | 0.0196 (1)* | |
Geometric parameters (Å, º) top
K—Oi | 2.779 (1) | C—Oix | 1.284 (1) |
K—Oii | 2.779 (1) | C—Ovi | 1.284 (1) |
K—Oiii | 2.779 (1) | Ca—Oii | 2.557 (1) |
K—Oiv | 2.779 (1) | Ca—Ox | 2.557 (1) |
K—Ov | 2.779 (1) | Ca—Oxi | 2.557 (1) |
K—Ovi | 2.779 (1) | Ca—Oix | 2.557 (1) |
K—Fvii | 2.9450 (1) | Ca—Ovi | 2.557 (1) |
K—Fviii | 2.9450 (1) | Ca—Oxii | 2.557 (1) |
K—F | 2.9450 (1) | Ca—F | 2.2275 (1) |
C—O | 1.284 (1) | Ca—Fxiii | 2.2275 (1) |
| | | |
O—C—Oix | 120 | Oix—C—Ovi | 120 |
O—C—Ovi | 120 | | |
Symmetry codes: (i) x−1, y, z−1; (ii) x−1, y, z; (iii) −y, x−y−1, z−1; (iv) −y, x−y−1, z; (v) −x+y+1, −x+1, z−1; (vi) −x+y+1, −x+1, z; (vii) x−1, y−1, z; (viii) x, y−1, z; (ix) −y+1, x−y, z; (x) x, y+1, z; (xi) −y, x−y, z; (xii) −x+y+1, −x+2, z; (xiii) x, y, z+1. |
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