Tables for
Volume H
Powder diffraction
Edited by C. J. Gilmore, J. A. Kaduk and H. Schenk

International Tables for Crystallography (2018). Vol. H, ch. 3.7, p. 308

Table 3.7.1 

J. A. Kaduka,b,c*

aDepartment of Chemistry, Illinois Institute of Technology, 3101 South Dearborn Street, Chicago, IL 60616, USA,bDepartment of Physics, North Central College, 131 South Loomis Street, Naperville, IL 60540, USA, and cPoly Crystallography Inc., 423 East Chicago Avenue, Naperville, IL 60540, USA
Correspondence e-mail:

Table 3.7.1| top | pdf |
Criteria for the assignment of quality marks to calculated patterns in the Powder Diffraction File

A Star (*/S) pattern has no warnings.

Minor warning (I)Significant warning (B)Major warning (O)
Density calculated from reported and calculated compositions differ (1% < x < 3%) Density calculated from reported and calculated compositions differ (1% < x < 15%) Density calculated from reported and calculated compositions differ (15% < x)
No e.s.d. reported/abstracted on cell dimensions Lattice parameters taken from figure (approximated) Incorrect lattice parameters
Magnitude of e.s.d.s on lattice parameters > 1000 p.p.m. Missing decimal point in lattice parameter Incorrect space group
0.07 < R < 0.12 (single crystal), 0.10 < R < 0.15 (powder) 0.12 < R (single crystal), 0.15 < R (powder) Incommensurate/modulated structure. Only average structure of the subcell is given.
No R reported/abstracted Anisotropic displacement tensor is non-positive definite Published atomic coordinates are wrong
Reported Z is inconsistent with the sum of the site multiplicities Anisotropic tensor coefficient not permitted by site symmetry Structural database removed the entry corresponding to a published calculated pattern
Type of experiment (single crystal/powder) is not mentioned Magnitude of displacement coefficients outside the range 0.001 < U < 0.1 Å2  
Structure corrected by the editor Uiso < 0.0  
Difference between measured and calculated density > 2% Source-database warning on bond length/angle  
Misprint in original paper corrected in database Average structure of a modulated structure  
Site occupation factor > 1.0 Probable site-occupation factor deduced from the nominal composition  
  Part of the structure was refined as a group without locating the constituent atoms  
  Comments containing a reference to a contradicting structure exist  
  Structure determined from projections  
  Structure determined using electron diffraction