Discussion List Archives

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: _atom_site_aniso_label is broken

Hi Brian,

Yes, the timing was a bit unfortunate, especially given that DDL1.4 has
been out there for many years.

> To resolve this error of logic, we shall drop "_list_mandatory yes" from
> the definition of _atom_site_aniso_label that goes out with Volume G (I
> expect to release all the Volume-G compatible dictionaries within the next
> couple of weeks).

There is also the _list_reference problem, whereby _atom_site_aniso_
items have _atom_site_aniso_label as their _list_reference, which would
mean that when _atom_site_aniso items appear in a single loop with
_atom_site_items _atom_site_aniso_label still has to be in the loop.  

> Volume G also contains some discussion of the ATOM_SITE list problem which
> make it clear what the intention is (in just the way elaborated in the
> discussions on this list last week).
> 
> It is too late in the day to make last-minute changes to DDL1.4 definitions
> for release with this Volume - without careful thought and testing there is
> too high a risk of introducing bad side-effects from what appear to be
> sensible modifications. It seems to me that James certainly has the flavour
> of the type of thinking that is needed to interpret the existing
> definitions, and better documentation ought to make the suggested
> procedures explicit, but I think that can only be done when *and if*
> there are functioning reference implementations for full DDL1.4-based
> validators.

Speaking of full DDL1.4 validators, I think I'll have something to show
you in Florence.

There are a number of alternative resolutions to the
_atom_site_aniso_label problem - would it be useful to talk about them
here, or would doing it on the spot (if considered necessary) in
Florence be more effective?

> Florence will provide a great opportunity for the CIF community to consider
> to what extent (if any) DDL1.4 should still be considered "supported",
> and I'm very glad that you will be there, James.

"Un"supporting DDL1.4 is a topic that should provoke plenty of spirited
discussion... is 7 days enough?

See you,
James.
_______________________________________________
cif-developers mailing list
cif-developers@iucr.org
http://scripts.iucr.org/mailman/listinfo/cif-developers

Reply to: [list | sender only]
International Union of Crystallography

Scientific Union Member of the International Council for Science (admitted 1947). Member of CODATA, the ICSU Committee on Data. Member of ICSTI, the International Council for Scientific and Technical Information. Partner with UNESCO, the United Nations Educational, Scientific and Cultural Organization in the International Year of Crystallography 2014.

ICSU Scientific Freedom Policy

The IUCr observes the basic policy of non-discrimination and affirms the right and freedom of scientists to associate in international scientific activity without regard to such factors as ethnic origin, religion, citizenship, language, political stance, gender, sex or age, in accordance with the Statutes of the International Council for Science.