The Commission concentrated its efforts along two main directions. First,
the establishment of rules and standards for the publication
of crystal data for aperiodic structures and, second, the preparation
and coordination of symposia and conferences on aperiodic
crystals.
Following the establishment of a checklist for the publication of incommensurate
crystals, the Commission pursued its work on the
preparation of a CIF dictionary for modulated structures. The work
is currently in progress and a proposition close to the final draft is
already available on the web. This draft will be improved and completed
from the feedback of the specialists working in the field of
incommensurate crystals. A preliminary database containing more than
50 modulated structures has been prepared for test purposes.
The checklist for the publication of incommensurate crystal structures
is directly available from the IUCr web site.
The Proceedings of Aperiodic '97 have been edited by the organizers
of the conference, M. de Boissieu, J.-L. Verger-Gaugry & R.
Currat. They are currently available (World Scientific, Singapore,
1998). The book by C. Janot and J.-M Dubois entitled Les
Quasicristaux, Matière Paradoxe has also been published (EDP
Sciences, Les Ulis, 1998).
The Commission was actively involved in the preparation of ECM-18, Prague,
Czech Republic, with a microsymposium dedicated to
aperiodic crystals. Some members contributed actively to the creation
of a special interest group (SIG) on aperiodic crystals within
the European Crystallographic Association. The web site specially dedicated
to this SIG (http://www-xray.fzu.cz/sgip/aphome.html )
gives an exhaustive list of activities related to aperiodic crystals
that occurred in 1998 in which members of this Commission were
involved to various degrees. Let us mention in addition the organization
of the Fall 1998 meeting of the Materials Research Society
on Quasicrystals which took place in Boston, USA, and the French-German
Colloquium on Quasicrystals which took place in
Strasbourg, France, in April 1998.
The Commission contributed to the organization of two microsymposia
dedicated to various aspects of aperiodic crystals, which will
take place in 1999 during the Glasgow Congress. The Commission is presently
working on the preparation of the next Aperiodic
Conference which will be organized in Nijmegen, The Netherlands, in
Summer 2000.
G. CHAPUIS, Chair