[sdpd] Re: indexing superstructures

[Armel Le Bail <armel... @fluo.univ-lemans.fr>]

Jean-Marc Joubert
>
>I would like to know if exists a software devoted to the indexation of
>superstructure lines in a powder pattern.
>
>i.e. : I have a powder pattern and managed to index (by analogy with a known
>structure) the majority of the lines. I have some remaining unindexed lines
>and am pretty sure that they do not belong to an additional phase.
>        I wonder if exists some software taking into account (contrary to
>the usual indexation programs like dicvol, treor) the cell already indexed
>and trying to index the remaining lines in a supercell automatically.

I never heard about such a special software. However, the best adapted
existing indexing program is Dicvol, certainly. Due to the exhaustivity
of the search performed by Dicvol, and to the fact that no unindexed
line is tolerated, if you have already a set of indexed lines, then, just
adding
one line doubling (or multiplying by any value) any axis, and Dicvol
will find the superstructure. You cannot expect that from Treor
or Ito as systematically as with Dicvol.

Hope this helps,

Armel Le Bail - Universite du Maine, Laboratoire des Fluorures,
CNRS ESA 6010, Av. O. Messiaen, 72085 Le Mans Cedex 9, France
http://www.cristal.org/