Teaching crystallography at University level is a very challenging task for many reasons. The interdisciplinary character of crystallography is such that it is taught to most students in basic sciences (physics, chemistry, biology) and applied sciences (mineralogy, material sciences). The diversity of the student profiles is reflected in a large variety of background knowledges which should be taken into account by the teachers. In other words, each course should be tailored according to the student orientations and requirements.

In view of this, we have developed a series of applets each representing some specific aspects of crystallography teaching covering among others the concepts of point and space group symmetry, basic crystal structures, diffraction and structure resolution. Each applet can be considered as a module which can be combined with many others according to the need of the lecture. In our presentation, we shall illustrate the use of various applets which we developed in combination with others available on the web. The applets can also be combined with various open databases, including the Bilbao crystallographic server, which are freely available on Internet.

The lecture will take place interactively. After a short introduction, each topic selected from the domains of point and space group symmetry, structure representations, Fourier transform and diffraction will be presented and illustrated first. Each participant will have then the opportunity to solve some specific exercises interactively with the applets and databases.

Pre-requirements: Internet connected browser with java 3d API. The applets can be accessed at http://lcr.epfl.ch/page37304.html.

Supplementary Material