>it's a very good idea to put such a list on the web. If it is regularly
>updated it would also help to spread structural information faster than
>the ICSD (which is always lagging behind a considerable time), and
>would help to avoid double work.
Doing so would need a full-time job for someone having
access to a complete bibliography. I will not do that.
Ten years ago, or more, I suggested that colleagues in my lab should
add their last structure determination in a list of cell parameters
and chemical formula placed in the four-circle diffractometer
room. This failed, and different people continued to determine
the same crystal structure twice sometimes, in the same lab,
due to lack of communication willing...
I would suggest to operate such a list on an international scale, on the
Internet, if I could believe that it would really work. But I believe
that it would not work at all... People do not want to say what they
are doing. Same structures will continue to be determined
2 or 3 times (more for the simplest ;: 63 entries for rutile in
ICSD...). Maybe this will be worst now due to my list of unknown
mineral structures, if several people start the same study ;-).
Anyway, I will update the list, thanks to your informations about
recent structure determinations.
Realizing a part of that list of unknown structures was easy.
213 names are obtained from the WebMineral Web site, searching
for the "unk" keyword. This gives minerals with unknown space
group. Anyway, "known" space group does not mean known
structure at all. So that the number of mineral with unknown
structure is estimated to be really much larger... Other names
came from more "secret" data. One can regret that ICDD does
not use such an "unk" key for many of its own powder data entries.
At least the adding of calculated powder patterns from ICSD into
the ICDD has clarified the situation for >40000 entries...
Armel Le Bail
http://sdpd.univ-lemans.fr/course/
