Acta Cryst. (2006). E62, i77-i79  [ doi:10.1107/S1600536806007288 ]

Uranium and aluminium order-disorder in U_1-xPt₂Al_7-6x [x = 0.33 (1)]

S. Bobev, E. D. Bauer and J. L. Sarrao

Online 3 March 2006

Key indicators

• Single-crystal X-ray study
• T = 120 K
• Mean (t-Al) = 0.002 Å
• Disorder in main residue
• R factor = 0.020
• wR factor = 0.039
• Data-to-parameter ratio = 8.1

checkCIF/PLATON results

No syntax errors found




Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT045_ALERT_1_C Calculated and Reported Z Differ by ............       2.00 Ratio 
PLAT068_ALERT_1_C Reported F000 Differs from Calcd (or Missing)...          ?
PLAT077_ALERT_4_C Unitcell contains non-integer number of atoms ..          ?
PLAT088_ALERT_3_C Poor Data / Parameter Ratio ....................       8.11       
PLAT301_ALERT_3_C Main Residue  Disorder .........................       5.00 Perc. 

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:Al5 Pt2 U0.67
            Atom count from the _atom_site data:  Al5.047 Pt2 U0.67
CELLZ01_ALERT_1_G Difference between formula and atom_site contents detected.
CELLZ01_ALERT_1_G ALERT: check formula stoichiometry or atom site occupancies.
           From the CIF: _cell_formula_units_Z    2
           From the CIF: _chemical_formula_sum  Al5 Pt2 U0.67
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           Al        10.00     10.09   -0.09
           Pt         4.00      4.00    0.00
           U          1.34      1.34    0.00

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

   6 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 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
   1 ALERT type 4 Improvement, methodology, query or suggestion

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