Application of optimization to powder-pattern indexing

The optimization method of indexing powder diffraction patterns based on minimizing the suitable criterion function within a required range of unit-cell parameters is presented. The features of the method are discussed. A comupter program is described which performs the optimization in two steps: systematic search and Powell method. The results are refined by the least-squares method. The actual version indexes patterns of orthorhombic or higher symmetry. (orig.)