Calc. Patterns Quality Marks in Release 2005

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Calc. Patterns Quality Marks in Release 2005

• Suri Kabekkodu

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• A calculated patterns quality mark task group was
  formed during the ICDD spring meeting 2003 in
  order to develop a method to assign quality marks
  to calculated patterns.
• S. Kabekkodu (Chair), C. Hubbard,
  J. Kaduk, E. Antipov, M. Bennett, P. Wallace,
  F. Rotella

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Scope and Considerations

• The focus of the quality mark is to determine the
  confidence level of the structural model used and
  its impact on the calculated pattern (especially
  for the purpose of phase identification).
• The method should involve rigorous
  crystallographic and additional editorial checks
  by the ICDD and warning comments from our
  collaborating structural databases
  (ICSD/CSD/NIST/LPF).

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Program Development

• Several crystallographic and other data checking
  programs were developed by the ICDD to achieve
  this goal.
• To name a few
• Temperature factors analysis
• Non positive definite matrix check
• Range check
• Checking the space group choice of origin
• Composition check (reported Vs refined)
• Several keyword based queries to extract
  external database comments/warnings

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LPF
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ICSD
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NIST
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Population of Editors comments after assigning
quality mark to all the calculated
patterns(394,175)
SOURCE DATA NUMBER OF ENTRIES MINOR WARNING SIGNIFICANT WARNING MAJOR WARNING TOTAL
LPF 78769 71121 8766 3 79890
ICSD 68404 45874 38037 372 84283
NIST 9802 15784 1559 10 17353
CSD 237200 106772 51455 423 161350
Total 394175 239551 99817 808 342876