A computer program for the calculation of lattice spacings from Kossel diffraction patterns

A computer program, written in Whetstone Algol, is described for handling the arithmetical operations involved in a precision method of determining lattice spacings from Kossel diffraction patterns. The interpretation treats the Kossel pattern as a three-dimensional array of intersecting cones with a common vertex and depends on the fact that when three or more positions of a cone generator are established, its axis and semivertex angle are defined. The theory and experimental requirements of the method are outlined and the functions of the steps in the computer program are described. The full program, together with data sheets and print-out of results for a typical calculation is available on request. A subsidiary program is also available to provide a graphical display of relevant parts of the results.