(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]

Acta Cryst. (2002). E58, o1415-o1417 [ doi:10.1107/S1600536802020974 ]

2(S)-N-tert-Butoxycarbonylamino-N-methoxy-N-methylbutanamide

P. Sawatzki, T. Mikeska, M. Nieger, H. Hupfer and T. Kolter

Online 30 November 2002

Key indicators

Single-crystal X-ray study
T = 123 K
Mean (C-C) = 0.002 Å
R factor = 0.034
wR factor = 0.090
Data-to-parameter ratio = 21.1

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



STRVAL_01                                                                       
         From the CIF: _refine_ls_abs_structure_Flack    0.200                  
         From the CIF: _refine_ls_abs_structure_Flack_su    0.800               
           Alert C Flack test results are meaningless.                          

General Notes



REFLT_03                                                                        
         From the CIF: _diffrn_reflns_theta_max           28.29                 
         From the CIF: _reflns_number_total               3362                  
         Count of symmetry unique reflns         1970                           
         Completeness (_total/calc)            170.66%                          
         TEST3: Check Friedels for noncentro structure                          
         Estimate of Friedel pairs measured      1392                           
         Fraction of Friedel pairs measured     0.707                           
         Are heavy atom types Z>Si present           no                         
          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.     


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 1 Alert Level C = Please check