Acta Cryst. (2009). E65, i75  [ doi:10.1107/S1600536809040355 ]

NaSr(AsO₄)(H₂O)₉: the (Sr,As) analogue of nabaphite and nastrophite

M. Weil

Online 10 October 2009

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean () = 0.000 Å
• H-atom completeness 1%
• Disorder in main residue
• R factor = 0.023
• wR factor = 0.056
• Data-to-parameter ratio = 57.2

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT306_ALERT_2_A Isolated Oxygen Atom (H-atoms Missing ?) .......         O1     

PLAT306_ALERT_2_A Isolated Oxygen Atom (H-atoms Missing ?) .......         O2     

PLAT306_ALERT_2_A Isolated Oxygen Atom (H-atoms Missing ?) .......         O3     

Alert level C
CHEMW03_ALERT_2_C The ratio of given/expected molecular weight as
            calculated from the _atom_site* data lies outside
            the range 0.99 <> 1.01
           From the CIF: _cell_formula_units_Z                    4
           From the CIF: _chemical_formula_weight           411.67
           TEST: Calculate formula weight from _atom_site_*
           atom     mass    num     sum
           O        16.00   12.99  207.83
           H         1.01    0.00    0.00
           Na       22.99    1.00   22.99
           As       74.92    1.00   74.92
           Sr       87.62    1.00   87.62
           Calculated formula weight              393.36
PLAT313_ALERT_2_C Oxygen with three covalent bonds (rare) ........         O8     
PLAT041_ALERT_1_C Calc. and Reported SumFormula    Strings  Differ          ?
PLAT043_ALERT_1_C Check Reported Molecular Weight ................     411.67      
PLAT044_ALERT_1_C Calculated and Reported Dx Differ ..............          ?
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)...          ?
PLAT141_ALERT_4_C su on a - Axis Small or Missing (x 100000) .....         10 Ang. 
PLAT952_ALERT_1_C Reported and Calculated Lmax Values Differ by ..          4      

Alert level G
FORMU01_ALERT_2_G  There is a discrepancy between the atom counts in the
            _chemical_formula_sum and the formula from the _atom_site* data.
            Atom count from _chemical_formula_sum:H18 As1 Na1 O13 Sr1
            Atom count from the _atom_site data:  As1 Na1 O12.99 Sr1
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G WARNING: H atoms missing from atom site list. Is this intentional?
           From the CIF: _cell_formula_units_Z    4
           From the CIF: _chemical_formula_sum  As H18 Na O13 Sr
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           As         4.00      4.00    0.00
           H         72.00      0.00   72.00
           Na         4.00      4.00    0.00
           O         52.00     51.96    0.04
           Sr         4.00      4.00    0.00
REFLT03_ALERT_1_G ALERT: Expected hkl max differ from CIF values
           From the CIF: _diffrn_reflns_theta_max           45.67
           From the CIF: _reflns_number_total               3435
           From the CIF: _diffrn_reflns_limit_ max hkl   21.   21.   17.
           From the CIF: _diffrn_reflns_limit_ min hkl  -21.  -20.  -17.
           TEST1: Expected hkl limits for theta max
           Calculated maximum hkl   21.   21.   21.
           Calculated minimum hkl  -21.  -21.  -21.
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           45.67
           From the CIF: _reflns_number_total               3435
           Count of symmetry unique reflns         1906
           Completeness (_total/calc)            180.22%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      1529
           Fraction of Friedel pairs measured     0.802
           Are heavy atom types Z>Si present        yes
PLAT301_ALERT_3_G Note: Main Residue  Disorder ...................      18.00 Perc.
PLAT779_ALERT_4_G Suspect or Irrelevant (Bond) Angle in CIF ......      19.90 Deg. 
              O8   -AS   -O9      1.555   1.555   1.555                        
PLAT779_ALERT_4_G Suspect or Irrelevant (Bond) Angle in CIF ......      19.90 Deg. 
              O8   -AS   -O9      9.555   1.555   9.555                        
PLAT779_ALERT_4_G Suspect or Irrelevant (Bond) Angle in CIF ......      19.90 Deg. 
              O8   -AS   -O9      5.555   1.555   5.555                        
PLAT811_ALERT_5_G No ADDSYM Analysis: Too Many Excluded Atoms ....          !

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

   8 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   6 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   5 ALERT type 4 Improvement, methodology, query or suggestion
   1 ALERT type 5 Informative message, check

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