The use of CCD area detectors in charge-density research. Application to amineral compound: the alpha-spodumene LiAl(SiO3)(2)

X-ray diffraction data sets collected on both Nonius and Siemens (Bruker) g oniometers equipped with charge-coupled device (CCD) area detectors have be en tested for the electron-density determination of the aluminosilicate min eral compound alpha-spodumene LiAl(SiO3)(2), aluminium lithium silicon oxid e. Data collection strategies, reflection intensity peak integration method s and experimental error estimates are different for the two instruments. T herefore, the consistency and quality of the two types of CCD measurements have been carefully compared to each other and to high-resolution data coll ected on a conventional CAD-4 point-detector diffractometer. Multipole dens ity model refinements were carried out against the CCD data and the statist ical factors analysed in terms of experimental weighting schemes based on t he standard uncertainties of the diffraction intensities derived by the Non ius and Siemens software programs. Consistent experimental electron-density features in the Si-O-Si and Si-O-Al bridges were found from both CCD data sets. The net atomic charges obtained from the kappa refinements against ea ch CCD data set are also in good agreement and quite comparable with the re sults of the conventional CAD-4 experiment.