Ambiguous structure determination from powder data: four different structural models of 4,11-difluoroquinacridone with similar X-ray powder patterns, fit to the PDF, SSNMR and DFT-... oleh Carina Schlesinger, Arnd Fitterer, Christian Buchsbaum, Stefan Habermehl, Michele R. Chierotti, Carlo Nervi, Martin U. Schmidt