Computerized Linear Coordinate Nets in Crystallography

On the basis of the gnomonic projection, a new concept, the linear coordinate net (LCN) of crystals, is presented. With such nets, the Miller indices of Laue spots and the orientation of the crystal can be read directly without any calculation or graphical operation. These nets can be constructed with an IBM personal computer. In this paper, the principle and formulas, the computer program for constructing the nets and the applications of the LCNs are described. The main applications are when the incident X-rays are in a low-indices direction or are perpendicular to a plane with low Miller indices.