Special Interest Group (SIG)
Aperiodic Crystals
in the ECA

1. Scope.

The aim of the SIG is to stimulate scientific work on structure and physical properties of aperiodic crystals, and contact between researchers in the field. By aperiodic crystals are meant all well ordered solid state systems without lattice periodicity. The main classes are incommensurate modulated systems, incommensurate magnetic systems, incommensurate composites, polytypes and quasicrystals. Theoretical and experimental workers in this field are welcome as members. The activities of the SIG should not overlap with those of the IUCr Committee on Aperiodic Crystals.

2. Programme.

• Set-up of a web-site with information relevant for the community, such as meetings, news, addresses, and vacancies.
• Formation of a pool of available software. Access to and/or information about this will be given via the website.
• Making of suggestions for (plenary) talks and satellite symposia at ECM meetings.
• Writing of a tutorial on aperiodic crystals. This can be installed at the website.
• Stimulating discussion between the subhead "modulated phases", "incommensurate composites", and "quasicrystals", by the organization of a work group on common problems, or of a workshop (e.g. on "phasons").
• Organization of a school on aperiodic crystals.
• The set-up of an electronic platform for rapid communication and discussions.
• Giving advice for consultation about European and international collaboration in this field.

The activities should be coordinated with those of the IUCr/Aperiodic Committee (via the colleagues belonging to both committees) and of the community of quasicrystallographers organizing the ICQ meetings.

3.Organization

1. The activities of the SIG are directed by a steering committee with between 10 members and 16 members. One of the members acts as chairman, another as secretary. The composition of the committee should be representative for the geographical spread and the spread over the subhead.
2. At least once a year, 3 months before the European or International Meeting on Crystallography, members are asked by the secretary for proposals for activities and for their opinion about the functioning of the SIG.

4. Steering Committee