(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2011). E67, o149 [ doi:10.1107/S1600536810052153 ]

2,4,6-Trimethylpyridinium dihydrogen phosphate

J. Dai and J. Xu

Online 18 December 2010

Key indicators

Single-crystal X-ray study
T = 298 K
Mean (C-C) = 0.004 Å
R factor = 0.044
wR factor = 0.101
Data-to-parameter ratio = 18.1

checkCIF/PLATON results

No syntax errors found




Alert level C
PLAT242_ALERT_2_C Check Low       Ueq as Compared to Neighbors for         P2     
PLAT245_ALERT_2_C U(iso) H5      Smaller than U(eq) O5      by ...       0.01 AngSq
PLAT910_ALERT_3_C Missing # of FCF Reflections Below Th(Min) .....          5      

Alert level G
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           27.48
           From the CIF: _reflns_number_total               4970
           Count of symmetry unique reflns         2593
           Completeness (_total/calc)            191.67%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured      2377
           Fraction of Friedel pairs measured     0.917
           Are heavy atom types Z>Si present        yes
PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints .......          5      

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   2 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
   2 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check