Acta Cryst. (2007). E63, i157  [ doi:10.1107/S1600536807027043 ]

Langbeinite-type Rb₂Ca₂(SO₄)₃

M. Boujelben, M. Toumi and T. Mhiri

Online 15 June 2007

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean (S-O) = 0.010 Å
• R factor = 0.065
• wR factor = 0.128
• Data-to-parameter ratio = 18.3

checkCIF/PLATON results

No syntax errors found




Alert level B
PLAT031_ALERT_4_B Refined Extinction Parameter within Range ......       1.60 Sigma

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for          S     
PLAT850_ALERT_2_C Check Flack Parameter Exact Value 0.00 and su ..       0.04      

Alert level G
REFLT03_ALERT_1_G ALERT: Expected hkl max differ from CIF values
           From the CIF: _diffrn_reflns_theta_max           29.89
           From the CIF: _reflns_number_total               1080
           From the CIF: _diffrn_reflns_limit_ max hkl    9.   10.   14.
           From the CIF: _diffrn_reflns_limit_ min hkl   -8.  -10.  -14.
           TEST1: Expected hkl limits for theta max
           Calculated maximum hkl   14.   14.   14.
           Calculated minimum hkl  -14.  -14.  -14.
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           29.89
           From the CIF: _reflns_number_total               1080
           Count of symmetry unique reflns          654
           Completeness (_total/calc)            165.14%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       426
           Fraction of Friedel pairs measured     0.651
           Are heavy atom types Z>Si present        yes
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K    

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   3 ALERT level G = General alerts; check

   3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 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
   0 ALERT type 5 Informative message, check

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