As already demonstrated by Wessel et al. it is possible to take advantage of texture to extract single crystal like structure factors. Their actual procedure involves: a) the preparation of a textured sample, b) the analysis of the ODF (Orientation Distribution Function) by a dedicated measurement and analysis using the traditional pole figure measurement and c) few high resolution spectra measurements to extract structure factors using the ODF as input. In the present work we outline a procedure to make a joint extraction of structure factors and ODF simultaneously. In particular the structure factors and the ODF are simultaneously refined in subsequent iteration cycles using only one set of data that may include or not high resolution spectra. The ODF is analyzed from the same spectra used for the structure factors extraction using a Rietveld like texture analysis. Everything has been implemented in the Rietveld software Maud. For the texture part the EWIMV method incorporated in Maud is well suited for general textures, where the standard components method may give better convergences for highly monomodal texture functions as found in fiber materials. The structure factor extraction is performed through a modified Le Bail procedure that can limit the overlapping part by using a reduced peak range. All the extracted structure factors from different spectra are weighted using the ODF obtained by the simultaneous texture analysis and are used as starting point for the subsequent iteration cycle. Cell, line profile parameters and errors are also refined all together in a Rietveld like fashion refinement. Minor phases or a second phase may be incorporated as well, so not limiting the procedure to only pure compounds. The main advantages of this procedure are: 1) only one measurement/instrument is needed for the experiment, thus eliminating possible misplacements between one measurement and another and reducing the total experimental time, 2) only one analysis tool is needed and 3) the joint refinement aim to improve the accuracy of the extracted structure factors. There are also some disadvantages as the structure factor extraction needs indeed high resolution spectra with long measurement time where the texture need more spectra at different tilting of the sample to be measured. The two goals are not easily comprised in one experiment/instrument.  We will show how the joint extraction can be done and how it can improve the accuracy of the extracted structure factors or otherwise being conducted on a lesser resolution set of data. Wessel T., Baerlocher Ch. and McCusker L. B. (1999). Science, 284, 477-479.

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1. Modeling crystallites and r.m.s. microstrain distributions with anisotropic broadening in the Rietveld method
2. Analysis of fiber diffraction transmission images using the Rietveld method