Download citation
Download citation
link to html
The structure of calcium chlorite, Ca(ClO2)2, has been refined from X-ray powder diffraction data using the Rietveld method. The compound crystallizes in the ortho­rhom­bic space group Ccca (Ccce), with Z = 4. The structure is based on separate layers parallel to the ac plane, consisting of calcium cations that are coordinated by chlorite anions; the O atoms form almost ideal square antiprisms. Within the layers, each anion bridges four metal cations. The Ca atoms are located on special positions of 222 symmetry, the Cl atoms lie on twofold axes and the O atoms are in general positions. The compound is isostructural with strontium chlorite, Sr(ClO2)2, and lead chlorite, Pb(ClO2)2.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S160053680503415X/wm6100sup1.cif
Contains datablocks global, I

rtv

Rietveld powder data file (CIF format) https://doi.org/10.1107/S160053680503415X/wm6100Isup2.rtv
Contains datablock I

Key indicators

  • Powder X-ray study
  • T = 293 K
  • Mean [sigma](l-O) = 0.003 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 PLAT129_ALERT_4_A Unusual Space group Specified .................. CCCA(C
Alert level B Crystal system given = orthorhombic PLAT431_ALERT_2_B Short Inter HL..A Contact Cl .. O .. 2.85 Ang. PLAT431_ALERT_2_B Short Inter HL..A Contact Cl .. O .. 2.85 Ang.
Alert level C REFI023_ALERT_1_C _refine_diff_density_max is missing Maximum value of final difference map (e A-3). The following tests will not be performed DIFMN_01,DIFMX_01,DIFMX_02 REFI024_ALERT_1_C _refine_diff_density_min is missing Minimum value of final difference map (e A-3). The following tests will not be performed DIFMN_01,DIFMN_02,DIFMN_03 PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings Differ .... ? PLAT430_ALERT_2_C Short Inter D...A Contact O .. O .. 2.88 Ang. PLAT799_ALERT_4_C Numeric Label on Displacement Par. Record ...... ?
1 ALERT level A = In general: serious problem 2 ALERT level B = Potentially serious problem 5 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 3 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 0 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion

Computing details top

Data collection: APD1700 Software (Philips, 1989); cell refinement: FULLPROF2k (Rodriguez-Carvajal, 2004); program(s) used to refine structure: FULLPROF2k; molecular graphics: BS (Ozawa & Kang, 2004); software used to prepare material for publication: WINPLOTR (Roisnel & Rodriguez-Carvajal, 2005).

calcium chlorate(III) top
Crystal data top
Ca(ClO2)2Z = 4
Mr = 174.98Dx = 2.798 Mg m3
Orthorhombic, Ccca(Ccce)Cu Kα radiation, λ = 1.54178 Å
a = 5.7434 (7) ÅT = 293 K
b = 12.6002 (9) ÅParticle morphology: plate-like
c = 5.7405 (7) Åwhite
V = 415.43 (8) Å3flat_sheet, 10 × 10 mm
Data collection top
Philips PW1700 powder
diffractometer
Data collection mode: reflection
Radiation source: sealed X-ray tubeScan method: step
Graphite monochromator2θmin = 5.041°, 2θmax = 145.041°, 2θstep = 0.020°
Specimen mounting: drifted powder on standard quartz sample holder
Refinement top
Least-squares matrix: full31 parameters
Rp = 0.1271 restraint
Rwp = 0.145Weighting scheme based on measured s.u.'s w = 1/[σ2(Yi)]
Rexp = 0.080(Δ/σ)max = 0.01
RBragg = 0.043Background function: six-coefficients polinomial function
7001 data pointsPreferred orientation correction: Icorr = Iobs[G2+(1 – G2)exp(G1α2)], where α is the acute angle between the scattering vector and the normal to the crystallites, G1 = -2.69(2), G2 = 0.102(1), axis [010], (Rietveld, 1969)
Profile function: split pseudo-Voigt
Special details top

Experimental. The experimental data were collected with Cu K? radiation (λ1=1.54060 Å, λ2=1.54439 Å) on a Philips PW1700 automatic diffractometer with Si as external standard.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
Ca0.000000.250000.250000.0054 (6)*
Cl0.500000.08227 (11)0.250000.0172 (4)*
O0.3337 (6)0.14953 (10)0.0865 (6)0.0321 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
???????
Geometric parameters (Å, º) top
Ca—O2.481 (3)Cl—O1.585 (3)
Ca—Oi2.499 (3)
O—Cl—Oii115.3 (3)
Symmetry codes: (i) x+1/2, y, z+1/2; (ii) x+1, y, z+1/2.
 

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