inorganic compounds
The structure of strontium chlorite, Sr(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 strontium 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 Sr 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 calcium chlorite, Ca(ClO2)2, and lead chlorite, Pb(ClO2)2.
Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536805034161/wm6101sup1.cif | |
Rietveld powder data file (CIF format) https://doi.org/10.1107/S1600536805034161/wm6101IIsup2.rtv |
Key indicators
- Powder X-ray study
- T = 293 K
- Mean (l-O) = 0.006 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 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 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 = 14.15 Cell volume su given = 11.00 PLAT087_ALERT_2_C Unsatisfactory S value (Too High) .............. 3.03 PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent ..... ? PLAT431_ALERT_2_C Short Inter HL..A Contact Cl .. O .. 3.07 Ang. PLAT431_ALERT_2_C Short Inter HL..A Contact Cl .. O .. 3.07 Ang. PLAT799_ALERT_4_C Numeric Label on Displacement Par. Record ...... ?
1 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 8 ALERT level C = Check and explain 0 ALERT level G = General alerts; check 4 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; software used to prepare material for publication: WINPLOTR (Roisnel & Rodriguez-Carvajal, 2005).
strontium chlorate(III) top
Crystal data top
Sr(ClO2)2 | Z = 4 |
Mr = 222.52 | Dx = 3.242 Mg m−3 |
Orthorhombic, Ccca(Ccce) | CuKα radiation, λ = 1.54178 Å |
a = 5.9799 (12) Å | T = 293 K |
b = 12.7519 (16) Å | Particle morphology: plate-like |
c = 5.9787 (12) Å | white |
V = 455.92 (11) Å3 | flat_sheet, 10 × 10 mm |
Data collection top
Philips PW1700 powder diffractometer | Data collection mode: reflection |
Radiation source: sealed X-ray tube | Scan method: step |
Graphite monochromator | 2θmin = 4.819°, 2θmax = 144.819°, 2θstep = 0.020° |
Specimen mounting: drifted powder on standard quartz sample holder |
Refinement top
Least-squares matrix: full | 28 parameters |
Rp = 0.136 | 1 restraint |
Rwp = 0.165 | Weighting scheme based on measured s.u.'s w = 1/[σ2(Yi)] |
Rexp = 0.055 | (Δ/σ)max = 0.01 |
RBragg = 0.057 | Background function: six-coefficients polinomial function |
7001 data points | Preferred 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 = -0.54(5), G2 = 0.29(3), axis [010], (Rietveld, 1969) |
Profile function: split pseudo-Voigt |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
x | y | z | Uiso*/Ueq | ||
Sr | 0.00000 | 0.25000 | 0.25000 | 0.0105 (4)* | |
Cl | 0.50000 | 0.07460 (16) | 0.25000 | 0.0215 (7)* | |
O | 0.3443 (10) | 0.1447 (4) | 0.1005 (10) | 0.050 (2)* |
Geometric parameters (Å, º) top
Sr—O | 2.615 (6) | Cl—O | 1.570 (6) |
Sr—Oi | 2.657 (6) | ||
O—Cl—Oii | 110.6 (6) |
Symmetry codes: (i) −x+1/2, y, z+1/2; (ii) −x+1, y, −z+1/2. |