(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2005). E61, o2610-o2612 [ doi:10.1107/S1600536805022476 ]

2,3,3',4'-Tetramethylbiphenyl

A. J. Robertson and D. J. Price

Online 20 July 2005

Key indicators

Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.002 Å
R factor = 0.049
wR factor = 0.127
Data-to-parameter ratio = 18.0

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT761_ALERT_1_A CIF Contains no X-H Bonds ......................          ?

Author Response: All X-H bond lengths were constrained: These distances were fixed at 0.930 A for aryl-H bonds and 0.960 A for alkyl-H bonds. These constraints are discussed in the main text of the paper.

PLAT762_ALERT_1_A CIF Contains no X-Y-H or H-Y-H Angles ..........          ?

Author Response: As described above, the H atom position constraints fix these these angles. A deatiled accound of the constraints used appears in the main text.


Alert level C
ABSTM02_ALERT_3_C  The ratio of expected to reported Tmax/Tmin(RR') is < 0.90
            Tmin and Tmax reported:      0.830     0.991
            Tmin(prime) and Tmax expected:      0.971     0.991
            RR(prime) =      0.855
            Please check that your absorption correction is appropriate.
PLAT061_ALERT_3_C Tmax/Tmin Range Test RR' too Large .............       0.86       
PLAT199_ALERT_1_C Check the Reported _cell_measurement_temperature        293 K     
PLAT200_ALERT_1_C Check the Reported _diffrn_ambient_temperature .        293 K     

   2 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

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