Lukas Palatinus

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One of the applications of the maximum-entropy method (MEM) in crystallography is the reconstruction of the electron density from phased structure factors. Here the application of the MEM to incommensurately modulated crystals and incommensurate composite crystals is considered. The MEM is computed directly in superspace, where the electron density in the(More)
The charge flipping algorithm proposed by Oszlányi & Suto [Acta Cryst. (2004), A60, 134-141] for ab initio reconstruction of crystal structures is generalized towards superspace. Its efficiency is demonstrated by successful reconstruction of eight known incommensurately modulated structures from experimental data. The output of the charge flipping algorithm(More)
Hexagonal ferrites represent an extensive family of mixed-layer magnetic materials with periods up to 1500 A along the stacking direction, probably constituting the largest unit cells in the inorganic realm. The (TS)(n)T subfamily includes P3m1 and R3m structures that can be derived from Y ferrite Ba(2)M(2)Fe(12)O(22) (M = Zn, Fe, Co, Mg, Mn) by introducing(More)
The method of the prior-derived F constraints (PDC) enhances the quality of reconstructions of electron densities from X-ray diffraction data by the maximum-entropy method (MEM). The method concentrates on artifacts arising due to inaccurate extrapolation of non-measured data by the MEM. While these artifacts are unavoidable, when a flat prior is used, they(More)
Electron diffraction is a unique tool for analysing the crystal structures of very small crystals. In particular, precession electron diffraction has been shown to be a useful method for ab initio structure solution. In this work it is demonstrated that precession electron diffraction data can also be successfully used for structure refinement, if the(More)
BACKGROUND Nanofibrous scaffolds loaded with bioactive nanoparticles are promising materials for bone tissue engineering. METHODS In this study, composite nanofibrous membranes containing a copolymer of L-lactide and glycolide (PLGA) and diamond nanoparticles were fabricated by an electrospinning technique. PLGA was dissolved in a mixture of methylene(More)
The charge-flipping algorithm (CFA) is a member of the diverse family of dual-space iterative phasing algorithms. These algorithms use alternating modifications in direct and reciprocal space to find a solution to the phase problem. The current state-of-the-art CFA is reviewed and it is put in the context of related dual-space algorithms with relevance for(More)
Previous high-resolution x-ray powder diffraction and transmission electron microscopy studies of the zeolite SSZ-57 could not fully elucidate the structural basis for its puzzling adsorption behavior, which appears to be intermediate between that of a medium- (10-ring) and a large-pore (12-ring) zeolite. Now by applying advanced crystallographic techniques(More)
We describe a novel type of ordering phenomenon associated with the incommensurate occupational modulation of bistable molecular magnetic state in a spin-crossover material. This unusual type of aperiodicity resulting from the ordering of multistable electronic states opens new possibilities for addressing such materials by light. Here we show that light(More)
The unprecedented bimetallic 2D coordination polymer {Fe[(Hg(SCN)3 )2 ](4,4'-bipy)2 }n exhibits a thermal high-spin (HS)↔low-spin (LS) staircase-like conversion characterized by a multi-step dependence of the HS molar fraction γHS . Between the fully HS (γHS =1) and LS (γHS =0) phases, two steps associated with different ordering appear in terms of(More)