(IUCr) Crystallography Journals Online checkcif report

Acta Cryst. (2007). E63, i87-i88 [ doi:10.1107/S160053680700832X ]

Terbium hydrogendiphosphate trihydrate: synthesis and non-merohedral twinning

R. Essehli, B. El Bali, M. Dusek, K. Fejfarova and M. Lachkar

Online 28 February 2007

Key indicators

Single-crystal X-ray study
T = 294 K
Mean (P-O) = 0.003 Å
H-atom completeness 72%
Disorder in main residue
R factor = 0.026
wR factor = 0.056
Data-to-parameter ratio = 23.6

checkCIF/PLATON results

No syntax errors found




Alert level B
PLAT021_ALERT_1_B Ratio Unique / Expected Reflections too High ...       1.89      

Alert level C
PLAT041_ALERT_1_C Calc. and Rep. SumFormula Strings    Differ ....          ?
PLAT042_ALERT_1_C Calc. and Rep. MoietyFormula Strings Differ ....          ?
PLAT154_ALERT_1_C The su's on the Cell Angles are Equal (x 10000)         600 Deg. 
PLAT213_ALERT_2_C Atom O1      has ADP max/min Ratio .............       3.50 oblat
PLAT220_ALERT_2_C Large Non-Solvent    O     Ueq(max)/Ueq(min) ...       2.56 Ratio
PLAT301_ALERT_3_C Main Residue  Disorder .........................       3.00 Perc.
PLAT311_ALERT_2_C Isolated Disordered Oxygen Atom (No H's ?) .....       >O11     

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:H7 O10 P2 Tb1
            Atom count from the _atom_site data:  H5 O10 P2 Tb1
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    2
           From the CIF: _chemical_formula_sum  H7 O10 P2 Tb1
           TEST: Compare cell contents of formula and atom_site data

           atom    Z*formula  cif sites diff
           H         14.00     10.00    4.00
           O         20.00     20.00    0.00
           P          4.00      4.00    0.00
           Tb         2.00      2.00    0.00

   0 ALERT level A = In general: serious problem
   1 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
   4 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
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check