(IUCr) Crystallography Journals Online checkcif report

Acta Cryst. (2008). E64, i85-i86 [ doi:10.1107/S1600536808039664 ]

Ammonium ytterbium(III) diphosphate(V)

K. Fejfarová, R. Essehli, B. El Bali and M. Dusek

Online 29 November 2008

Key indicators

Single-crystal X-ray study
T = 120 K
Mean (Yb-O) = 0.003 Å
R factor = 0.016
wR factor = 0.061
Data-to-parameter ratio = 12.7

checkCIF/PLATON results

No syntax errors found




Alert level B
PLAT213_ALERT_2_B Atom O2      has ADP max/min Ratio .............       4.30 prola

Author Response: Atom O3 is the bridging oxygen of the P~2~O~7~ unit while O1,4,5,7 participate in the hydrogen bonds to NH~4~. On the other hand, O2 and O6 are relatively loose in the structure and their ADP's are much larger, indicating a slight disorder which, however, cannot be described by splittimg of atomic positions because there are no distinct maxima in the difference Fourier map. The alerts correspond to atom O2.


Alert level C
            Value of measurement temperature given =   120.000
            Value of melting point given =     0.000
PLAT220_ALERT_2_C Large Non-Solvent    O     Ueq(max)/Ueq(min) ...       2.64 Ratio

Alert level G
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          4      

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

   0 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
   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