Diffraction peak shapes: a profile refinement method for badly resolved powder diagrams

A program has been specially written for biological powder spectra. Most existing programs are not suitable for such poorly resolved diagrams with broad bands in which individual peaks are not well separated. A more efficient version of the COMPLEX algorithm is used and this direct optimization method reduces the risk of false minima. Numerous internal parameters and options in the optimization algorithm as well as in the profile calculations lead to great flexibility. The performance and the limits of this version are tested by two applications on α-lactose monohydrate and native cellulose partial spectra. In the first case the results are excellent, according to values in the literature, and in the second case this program indicates some interesting features. This powerful algorithm can be used for more complicated refinements.