The flexibility of CIF is indeed infinite. Even the names of the
unit-cell dimsnsions are different in mmCIF and (small molecule) core CIF.
One of the main reasons why I had to bring out a new version of SHELXL
recently (SHELXL-2013 to replace SHELXL-97) was that in the
meantime COMCIFS committee had changed many of the names.
George
meantime the COMCIFS committee of the IUCr had changed many of the names.
On 08/07/2013 10:02 PM, Nat Echols wrote:
On Wed, Aug 7, 2013 at 12:54 PM, James Stroud <xtald...@gmail.com
<mailto:xtald...@gmail.com>> wrote:
All that needs to happen is that the community agree on
1. What is the finite set of essential/useful attributes of
macromolecular structural data.
2. What is the syntax of (a) accessing and (b) modifying those
attributes.
3. What is the syntax of selecting subsets of structural data
based on those attributes.
The resulting syntax (i.e. language) itself should be terse, easy
to learn, easy to use, and preferably easy to implement.
Ah, but the nice thing about mmCIF is that it isn't truly "finite" -
the PDB may limit what tags are actually included in the distributed
files, but there is nothing preventing other developers from including
their own tags, and there is a community process for extending the
officially defined tags. Item (2) is very well-established, unlike
the current chaos of REMARK records. I think (3) will be left to the
various libraries to deal with.
-Nat
--
Prof. George M. Sheldrick FRS
Dept. Structural Chemistry,
University of Goettingen,
Tammannstr. 4,
D37077 Goettingen, Germany
Tel. +49-551-39-33021 or -33068
Fax. +49-551-39-22582