(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2011). E67, o136 [ doi:10.1107/S1600536810051652 ]

6-Methoxy-4-methyl-2H-chromen-2-one

H.-K. Fun, J. H. Goh, D. Wu and Y. Zhang

Online 15 December 2010

Key indicators

Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.002 Å
R factor = 0.066
wR factor = 0.218
Data-to-parameter ratio = 21.7

checkCIF/PLATON results

No syntax errors found




Alert level C
DIFMX01_ALERT_2_C  The maximum difference density is > 0.1*ZMAX*0.75
            _refine_diff_density_max given =      0.698
            Test value =      0.600
DIFMX02_ALERT_1_C  The maximum difference density is > 0.1*ZMAX*0.75
            The relevant atom site should be identified.
PLAT094_ALERT_2_C Ratio of Maximum / Minimum Residual Density ....       3.56      
PLAT097_ALERT_2_C Large Reported Max.  (Positive) Residual Density       0.70 eA-3 
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         27      

Alert level G
PLAT153_ALERT_1_G The su's on the Cell Axes   are Equal (x 100000)         20 Ang. 
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal  (x 10000)        100 Deg. 
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K    
PLAT200_ALERT_1_G Check the Reported   _diffrn_ambient_temperature        293 K    

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

   5 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   3 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 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