(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2005). E61, o1041-o1042 [ doi:10.1107/S1600536805008093 ]

6,6,8a-Trimethyl-3a,6,7,8a-tetrahydrobenzo[b]furo[3,2-d]furan-2,4(3H,5H)-dione

B. Nagaraj, H. S. Yathirajan, P. Nagaraja and D. E. Lynch

Online 18 March 2005

Key indicators

Single-crystal X-ray study
T = 120 K
Mean (C-C) = 0.002 Å
R factor = 0.027
wR factor = 0.068
Data-to-parameter ratio = 14.8

checkCIF/PLATON results

No syntax errors found




Alert level B
PLAT024_ALERT_4_B Merging of Friedel Pairs is STRONGLY Indicated .          !

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?

Alert level G
REFLT03_ALERT_4_G  ALERT: MoKa measured Friedel data cannot be used to
                   determine absolute structure in a light-atom
                   study EXCEPT under VERY special conditions.
                   It is preferred that Friedel data is merged in such cases.
           From the CIF: _diffrn_reflns_theta_max           25.99
           From the CIF: _reflns_number_total               2343
           Count of symmetry unique reflns         1368
           Completeness (_total/calc)            171.27%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       975
           Fraction of Friedel pairs measured     0.713
           Are heavy atom types Z>Si present           no

   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

   1 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
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion