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Draft Annual report of COMCIFS for 2004

  • To: "Discussion list of the IUCr Committee for the Maintenance of the CIFStandard (COMCIFS)" <comcifs@iucr.org>
  • Subject: Draft Annual report of COMCIFS for 2004
  • From: David Brown <idbrown@mcmaster.ca>
  • Date: Mon, 24 Jan 2005 14:30:24 -0500
Dear Colleagues,

Each year I have to submit an annual report to the Executive Committee 
of the IUCr to whom we report.  I give below a draft of this report for 
2004.  Before preparing a final copy, I would like to receive input from 
members of the COMCIFS discussion group about items I have missed and 
items that I have misdescribed.  Please read through this draft and let 
me have your comments in the next week, as I have been asked to submit 
this report as soon as possible.

Annual Report of COMCIFS to the IUCr Executive Committee for 2004
                      2005-01-24  DRAFT ONLY 

COMCIFS is a committee appointed by the Executive Committee of the 
IUCr.  It is charged with the supervision of the Union's 
Crystallographic Information File (CIF) project.  The current members of 

    David Brown (chair)
    Helen Berman
    Herbert Bernstein
    Ralf Grosse-Kunstleve
    Syd Hall
    Gotzon Madariaga
    Brian McMahon
    John Westbrook

Except for meetings held during the IUCr General Assemblies, it conducts 
all its business by email.

This year COMCIFS has put considerable energy into the publication of 
International Tables for Crystallography Vol G, the volume that will 
contain a comprehensive account of the CIF project.  The deadline for 
the receipt of copy was at the end of 2003.  Since then the editors and 
the Chester Office have been working hard to ensure uniformity of 
presentation, and the authors have been checking the proofs in time for 
publication in 2005.  Checking the proofs has led to the discovery of 
minor changes that are needed in some of the CIF dictionaries.  A 
revised version of the image-CIF dictionary used for recording two 
dimensional diffraction images is expected to be approved during the 
coming year.

The Chester office has also embarked on a revision of the CIF template 
for reporting Rietveld refinements in Acta Cryst.  It has also begun an 
ambitious project to put International Tables Vol. A on the web, 
planning to add some interactive features that will provide a testing 
ground for the symmetry-CIF dictionary and will undoubtedly result in 
the need for a new and enlarged version.

As mentioned in last year's report, after fifteen years the coreCIF 
dictionary is in the process of a major revision.  A number of the 
simpler changes were approved at the end of 2003 as version 2.3, but 
during 2004 the Core Dictionary Maintenance Group has been struggling 
with the challenge of encoding descriptions of molecules, extended 
scattering density and twinning.  Exploring the different ways in which 
the chemical and crystallographic descriptions of a molecule can be 
linked has raised some fundamental questions about the methods of 
linking information that can only be resolved when we know the 
direction  in which CIF will develop in the future.  Information 
technology has seen major changes since the Union adopted CIF in 1990 
and COMCIFS now needs to plan carefully for the rational development of 
CIF over the next decade.

One of COMCIFS goals is to discourage the formation of CIF dialects.  It 
is therefore something of an embarrassment that CIF uses two different 
and incompatible Dictionary Definition Languages (DDL),  DDL1 being used 
for the small-cell coreCIF dictionary and DDL2 being used for the 
large-cell mmCIF dictionary.  Software developed for manipulating mmCIFs 
cannot read those written with the coreCIF dictionary and vice versa.  
Since the interface between the small- and large-cell structures is 
becoming an increasingly important area of study, COMCIFS needs to 
explore how these two standards can be made to converge.

The lack of CIF software continues to be a concern, though each year 
sees a few more applications added to the collection.  2004 has seen the 
publication of two CIF browser-editors: enCIFer was released by the 
Cambridge Crystallographic Data Centre and Brian Toby has released his 
program CIFEDIT.  Both read in the version of the dictionary that was 
used to create the CIF, putting the user just a mouse-click away from 
all the dictionary information about any item in the CIF.  This not only 
makes it easier to create CIFs, but the browser-editor does not have to 
be modified every time a new version of a dictionary appears.  Many of 
the frustrations of maintaining software would disappear if other 
applications made use of the machine-readability of CIF dictionaries. 

Respectfully submitted by I.David Brown, Chair of COMCIFS

fn:I.David Brown
org:McMaster University;Brockhouse Institute for Materials Research
adr:;;King St. W;Hamilton;Ontario;L8S 4M1;Canada
title:Professor Emeritus
tel;work:+905 525 9140 x 24710
tel;fax:+905 521 2773

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