(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2006). E62, o955-o956 [ doi:10.1107/S160053680600393X ]

Surprising orientation in ring synthesis of 3,5-dimethylpyrazin-2(1H)-one

M. Helliwell, Y. Yun and J. A. Joule

Online 8 February 2006

Key indicators

Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.005 Å
R factor = 0.041
wR factor = 0.110
Data-to-parameter ratio = 9.5

checkCIF/PLATON results

No syntax errors found



Datablock: 3c


Alert level A
REFLT03_ALERT_3_A  Reflection count < 85% complete (theta max?)
           From the CIF: _diffrn_reflns_theta_max           24.93
           From the CIF: _diffrn_reflns_theta_full          24.93
           From the CIF: _reflns_number_total                839
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         1146
           Completeness (_total/calc)             73.21%
PLAT022_ALERT_3_A Ratio Unique / Expected Reflections too Low ....       0.73       
PLAT027_ALERT_3_A _diffrn_reflns_theta_full (too) Low ............      24.93 Deg.  
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.73       

Alert level C
PLAT088_ALERT_3_C Poor Data / Parameter Ratio ....................       9.53       
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K     
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K     
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          5       

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

   2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   0 ALERT type 2 Indicator that the structure model may be wrong or deficient
   6 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion