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Acta Cryst. (2001). E57, i101-i103  [ doi:10.1107/S1600536801015896 ]

Hexagonal LuMnO3 revisited

B. B. Van Aken, A. Meetsma and T. T. M. Palstra

Online 27 October 2001

Key indicators

checkCIF results

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Amber Alert Alert Level B:



PLAT_111  Alert B ADDSYM detects (pseudo) centre of symmetry ...        100 Perc Fit
Author response: ... Attempts to fit the data on a crystal structure with a space group that contains higher symmetry, like P63/mcm, where unsuccessful. A.d.p.'s indicated that the atoms at the mirror plane ought to be split in two on each side of the mirror plane. For instance an inversion symmetry on z //simeq 0.252 forces the two inequivalent Lu positions to have identical values for their z parameter. As the z parameter is free on all P63cm positions and the current refinement separates the z parameters by as much as 0.04, equivalent to 0.25 \%A, it is very unlikely that a centre of symmetry is missed. 
PLAT_111  Alert B ADDSYM detects (pseudo) centre of symmetry ...        100 Perc Fit
Author response: ... Attempts to fit the data on a crystal structure with a space group that contains higher symmetry, like P63/mcm, where unsuccessful. A.d.p.'s indicated that the atoms at the mirror plane ought to be split in two on each side of the mirror plane. For instance an inversion symmetry on z //simeq 0.252 forces the two inequivalent Lu positions to have identical values for their z parameter. As the z parameter is free on all P63cm positions and the current refinement separates the z parameters by as much as 0.04, equivalent to 0.25 \%A, it is very unlikely that a centre of symmetry is missed. 

Yellow Alert Alert Level C:



DIFMN_02  Alert C The minimum difference density is < -0.1*ZMAX*0.75            
          _refine_diff_density_min given =     -5.600                           
          Test value =     -5.325                                               

DIFMN_03  Alert C The minimum difference density is < -0.1*ZMAX*0.75            
          The relevant atom site should be identified.                          

General Notes



ABSTM_02  The ratio of expected to reported Tmax/Tmin(RR) is > 2.00             
          Tmin and Tmax reported:      0.084     0.758                          
          Tmin and Tmax expected:      0.009     0.832                          
          RR =     10.210                                                       
          Please check that your absorption correction is appropriate.          

REFLT_03                                                                        
         From the CIF: _diffrn_reflns_theta_max           39.98                 
         From the CIF: _reflns_number_total                833                  
         Count of symmetry unique reflns          433                           
         Completeness (_total/calc)            192.38%                          
         TEST3: Check Friedels for noncentro structure                          
         Estimate of Friedel pairs measured       400                           
         Fraction of Friedel pairs measured     0.924                           
         Are heavy atom types Z>Si present          yes                         
          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

 2 Alert Level B = Potential problem

 2 Alert Level C = Please check

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