(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2004). E60, o1296-o1298 [ doi:10.1107/S1600536804015302 ]

2,3-Dihydroxy-N-methylbenzamide monohydrate

J. Escalada, D. Freedman and E. J. Werner

Online 9 July 2004

Key indicators

Single-crystal X-ray study
T = 126 K
Mean (C-C) = 0.003 Å
R factor = 0.043
wR factor = 0.052
Data-to-parameter ratio = 7.6

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT027_ALERT_3_A _diffrn_reflns_theta_full (too) Low ............      24.66 Deg.

Author Response: Due to a rapid drop-off in intensity of the data at high angle, we were unable to collect data to the limits recommended by checkCIF. Presumbaly this was due to poor ordering of the molecules, possibly the presence of the hydrogen-bonded water network caused this problem.

 In addition, this resulted in a lower than normal number of data to refine
 against leading to a relatively poor data to parameter ratio and several other
 level C alerts (for example sin(theta/lambda)).

 The slightly high Goodness-of-Fit value (2.024) results from refinement
 against F, rather than F^2.

 The T(min) and T(max) values reported were normalized, hence are a ratio.

 If there are any questions regarding the dataset, please do not hesitate to
 contact us.



Alert level B
ABSTM02_ALERT_3_B  The ratio of expected to reported Tmax/Tmin(RR') is < 0.75
            Tmin and Tmax reported:      0.572     0.982
            Tmin' and Tmax expected:      0.952     0.982
            RR' =      0.601
            Please check that your absorption correction is appropriate.
REFNR01_ALERT_3_B  Ratio of reflections to parameters is < 8 for a
            centrosymmetric structure
            sine(theta)/lambda                0.5871
            Proportion of unique data used    0.7610
            Ratio reflections to parameters   7.6391
PLAT061_ALERT_3_B Tmax/Tmin Range Test RR' too Large .............       0.60       
PLAT088_ALERT_3_B Poor Data / Parameter Ratio ....................       7.64       

Alert level C
GOODF01_ALERT_2_C  The least squares goodness of fit parameter lies
            outside the range 0.80 <> 2.00
            Goodness of fit given =      2.024
THETM01_ALERT_3_C  The value of sine(theta_max)/wavelength is less than 0.590
            Calculated sin(theta_max)/wavelength =    0.5871
PLAT023_ALERT_3_C Resolution (too) Low [sin(th)/Lambda < 0.6].....      24.66 Deg.  
PLAT029_ALERT_3_C _diffrn_measured_fraction_theta_full Low .......       0.96       
PLAT087_ALERT_2_C Unsatisfactory S value (Too High) ..............       2.02       
PLAT152_ALERT_1_C Supplied and Calc Volume s.u. Inconsistent .....          ?
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          2       
              H2 O                                                              

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

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