Polytype of illite clays solved by charge flipping
نویسندگان
چکیده
منابع مشابه
Structure of the polycrystalline zeolite catalyst IM-5 solved by enhanced charge flipping.
Despite substantial advances in crystal structure determination methodology for polycrystalline materials, some problems have remained intractable. A case in point is the zeolite catalyst IM-5, whose structure has eluded determination for almost 10 years. Here we present a charge-flipping structure-solution algorithm, extended to facilitate the combined use of powder diffraction and electron mi...
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This paper summarizes the current state of charge flipping, a recently developed algorithm of ab initio structure determination. Its operation is based on the perturbation of large plateaus of low electron density but not directly on atomicity. Such a working principle radically differs from that of classical direct methods and offers complementary applications. The list of successful structure...
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-Illite polytype quantification allows the differentiation of diagenetic and detrital illite components. In Paleozoic shales from the Illinois Basin, we observe 3 polytypes: 1M d, 1M and 2M~. 1M d and 1M are of diagenetic origin and 2M1 is of detrital origin. In this paper, we compare experimental X-ray diffraction (XRD) traces with traces calculated using WILDFIRE 9 and quantify mixtures of al...
متن کامل3 Ab initio structure solution by charge flipping
In this paper we present an extremely simple structure solution method termed charge flipping. It works ab initio on high resolution x-ray diffraction data in the manner of Fourier recycling. The real space modification simply changes the sign of charge density below a threshold, while in reciprocal space the modification is the F obs map without any weighting. We test the algorithm using synth...
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ژورنال
عنوان ژورنال: Acta Crystallographica Section A Foundations of Crystallography
سال: 2011
ISSN: 0108-7673
DOI: 10.1107/s0108767311087150