(IUCr) Crystallography Journals Online checkcif report

[Contents scheme]
Acta Cryst. (2001). E57, o916-o918 [ doi:10.1107/S1600536801014350 ]
L-Phenylalanine-nitric acid (2/1)

N. Srinivasan, B. Sridhar and R. K. Rajaram

Online 11 September 2001
Key indicators

Single-crystal X-ray study
T = 293 K
Mean (C-C) = 0.012 Å
H-atom completeness 70%
R factor = 0.069
wR factor = 0.220
Data-to-parameter ratio = 7.6
checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



ABSMU_01  Alert C The ratio of given/expected absorption coefficient lies       
          outside the range 0.99 <> 1.01                                        
          Calculated value of mu =     0.106                                    
          Value of mu given      =     0.110                                    

STRVAL_01                                                                       
         From the CIF: _refine_ls_abs_structure_Flack    0.000                  
         From the CIF: _refine_ls_abs_structure_Flack_su    4.000               
           Alert C Flack test results are meaningless.                          

General Notes



FORMU_01  There is a discrepancy between the atom counts in the                 
          _chemical_formula_sum and the formula from the _atom_site* data.      
          Atom count from _chemical_formula_sum:C18 H23 N3 O7                   
          Atom count from the _atom_site data:  C18 H16 N3 O7                   

CELLZ_01                                                                        
         From the CIF: _cell_formula_units_Z    2                               
         From the CIF: _chemical_formula_sum  C18 H23 N3 O7                     
         TEST: Compare cell contents of formula and atom_site data              
                                                                                
         atom    Z*formula  cif sites diff                                      
         C         36.00     36.00    0.00                                      
         H         46.00     32.00   14.00                                      
         N          6.00      6.00    0.00                                      
         O         14.00     14.00    0.00                                      
          Difference between formula and atom_site contents detected.           
          WARNING: H atoms missing from atom site list. Is this intentional?    

CHEMW_03                                                                        
         From the CIF: _cell_formula_units_Z                    2               
         From the CIF: _chemical_formula_weight           393.39                
         TEST: Calculate formula weight from _atom_site_*                       
         atom     mass    num     sum                                           
         C        12.01   18.00  216.20                                         
         N        14.01    3.00   42.02                                         
         O        16.00    7.00  111.99                                         
         H         1.01   16.00   16.13                                         
         Calculated formula weight              386.34                          
          The ratio of given/expected molecular weight as calculated            
          from the _atom_site* data lies outside                                
          the range 0.99 <> 1.01                                                

REFLT_03                                                                        
         From the CIF: _diffrn_reflns_theta_max           25.00                 
         From the CIF: _reflns_number_total               1895                  
         Count of symmetry unique reflns         1899                           
         Completeness (_total/calc)             99.79%                          
         TEST3: Check Friedels for noncentro structure                          
         Estimate of Friedel pairs measured         0                           
         Fraction of Friedel pairs measured     0.000                           
         Are heavy atom types Z>Si present           no                         
          Please check that the estimate of the number of Friedel pairs is      
          correct. If it is not, please give the correct count in the           
          _publ_section_exptl_refinement section of the submitted CIF.          


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 2 Alert Level C = Please check