Introduction to crystallography: two-dimensional computer simulations

Many elementary concepts of crystallography can be presented in two dimensions, where they are relatively easy to visualize. A computer simulation program for two-dimensional crystallography has been developed for use in teaching at an introductory level. The program will generate and display direct and reciprocal lattices, based on arbitrary user input, and is able to apply the symmetry operations of any of the 17 two-dimensional plane groups to a user-defined motif. Examples using the program are presented and discussed.