Drawing of crystal and twin figures

Abstract

A computer program for crystal figure drawing has been written with BASIC language. The program deals with three kinds of drawing: (1) the stereographic projection of crystal faces, (2) the drawing of a single crystal figure and (3) the drawing of a twin crystal figure. Face data are given by the values of ρ and φ from goniometric measurements or by Miller indices (hkl) with the lattice constants. The projection (1) facilitates us to find out the symmetry and zones of a crystal to be drawn. In the drawing (2), it is possible to draw the crystal figure viewed from any arbitrary direction. The twin crystal figure (3) is composed of only two individuals.