You will find applets dedicated to the three basic topics of crystallography, namely symmetry, diffraction and structure solution algorithms.

The symmetry applets range from learning the concept of point group symmetry, getting familiar with the symmetry of periodic objects in two dimensions, and also learning about the space group concept for the description of crystalline structures in 3D. An additional applet will help you in finding the new atomic coordinates of a new unit cell provided the matrix transformation from the original unit cell to the new one.

For diffraction, a simple animation of Bragg’s law will help to find the constructive interferences depending on the diffraction angle. Another applet will teach how to obtain the reciprocal lattice based on the original unit cell. Two applets illustrate the concept of Ewald sphere in order to understand the diffraction principles and simulate various diffraction methods. The user will be able to play with the concept of Fourier transform to generate the crystalline structures on the basis of diffraction patterns. From any CIF file (a crystallographic standard to describe atomic structures), the user will be able to simulate either powder or single crystal diffraction patterns.

Finally, the concepts of the Patterson function and the charge flipping algorithms are illustrated for a better understanding of the phase problem in crystallography.