Crystallography Journals Online : IUCR Backfile Archive 1948-2001
Image plates have advantages over photographic films, which include wider dynamic range, higher detector quantum efficiency, reduced exposure time and large size. In this study, an on-line image-plate system has been used to record crystallographic data from a small crystal. In particular, synchrotron Laue data were recorded with λmin = 0.455, λmax = 1.180 Å, in 20 images 10° apart and with an exposure time of 0.3 s each from a crystal (0.02 × 0.05 × 0.25 mm) of a nickel-containing aluminophosphate, NiAPO. The Laue data were analyzed with the Daresbury Laue software, including the application of an absorption correction. The structure was solved by a combination of the Patterson method and successive difference Fourier calculations using SHELXS86 and SHELXL93; the final R value for 1934 unique reflections (all data) and 310 parameters was 7.90%. The structure agrees with that determined by monochromatic diffractometry using the same crystal and reported by Helliwell, Gallois, Kariuki, Kaucic & Helliwell [Acta Cryst. (1993), B49, 420–428] with an r.m.s. deviation of 0.03 Å. Hence, this study shows the image-plate device to be very effective for synchrotron data collection and subsequent structure analysis from small crystals, i.e. 0.02 × 0.05 × 0.25 mm, in chemical crystallography as well as providing further confirmation of the practicability of Laue data in structure solution and refinement.
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