RSstitcher -- Seamless merging 2D diffraction frames for Wide Range Reciprocal Space Mappings

Abstract: Wide Range Reciprocal Space Mapping (WR-RSM) is a technique that allows visualisation of the geometric relationships among multiple hkl spots in a single reciprocal space map. However, current commercial software for reconstructing WR-RSM data suffers from several limitations, hindering its promotion. Here, we develop an open-source python program, named RSstitcher (Reciprocal Space Stitcher), to merge 2D diffraction frames measured at different cradle tilt angles into WR-RSMs, allowing the technique to be implemented on any laboratory X-ray diffractometer equipped with a goniometer cradle and a 2D detector. The conversion equations used in the python program is explained geometrically, including novel WR-RSM measurements in ω-φ compensated Side Inclination Grazing Incident Diffraction geometry for thin film samples. We demonstrate its application using two major 2D X-ray diffraction systems on the market, which generated similar WR-RSM results for bulk and thin film samples.