Abstract JANA2006 is a freely available program for structure determination of standard, modulated and magnetic samples based on X-ray or neutron single crystal/ powder diffraction electron diffraction. The system has been developed 30 years from specialized tool refinement structures to universal covering standard as well advanced crystallography. aim this article describe the basic features explain its scope philosophy. It will also serve basis future publications detailing tools methods JANA.

SUPERFLIP is a computer program that can solve crystal structures from diffraction data using the recently developed charge-flipping algorithm. It periodic structures, incommensurately modulated and quasicrystals X-ray neutron data. Structure solution powder supported by combining algorithm with histogram-matching procedure. written in Fortran90 distributed as source code precompiled binaries. has been successfully compiled tested on variety of operating systems.

EDMA is a computer program for topological analysis of discrete electron densities according to Bader's theory atoms in molecules. It locates critical points the density and calculates their principal curvatures. Furthermore, it partitions into atomic basins integrates volume charge these basins. can also assign type chemical element based on integrated charges. The latter feature be used interpretation ab initio obtained process structure solution. A particular that handle superspace...

A new method for space-group determination is described. It based on a symmetry analysis of the structure-factor phases resulting from structure solution in space group P 1. The output list all operations compatible with lattice. Each operation assigned agreement factor that used to select are elements structure. On basis selected complete constructed. independent number dimensions, and can also be aperiodic structures. cases described where this particularly advantageous compared...

The localization of hydrogen atoms is an essential part crystal structure analysis, but it difficult because their small scattering power. We report the direct in nanocrystalline materials, achieved using recently developed approach dynamical refinement precession electron diffraction tomography data. used this method to locate both organic (paracetamol) and inorganic (framework cobalt aluminophosphate) material. results demonstrate that technique can reliably reveal fine structural details,...

Electron diffraction tomography (EDT) data are in many ways similar to X-ray data. However, they also present certain specifics. One of the most noteworthy is specific rocking curve observed for EDT collected using precession electron method. This double-peaked (dubbed `the camel') may be described with an approximation based on a circular integral pseudo-Voigt function and used intensity extraction by profile fitting. Another aspect high likelihood errors estimation crystal orientation,...

Abstract We present the crystallographic program J ana 2020, successor of 2006. 2020 has new, technically different graphics and structure plot-driven intuitive control. Tools known from 2006 were revised inserted into a new logical scheme, their control connected with plot. Some tools considerably improved. focus on details most dynamically developing parts, namely twinned structures, magnetic analysis based electron diffraction data.

Determination of the absolute configuration organic molecules is essential in drug development and subsequent approval process. We show that this determination possible through electron diffraction using nanocrystalline material. Ab initio structure by has so far been limited to compounds maintain their crystallinity after a dose one per square angstrom or more. present complete analysis pharmaceutical cocrystal sofosbuvir l-proline, which about order magnitude less stable. Data collection...

Abstract Continuous-rotation 3D electron diffraction methods are increasingly popular for the structure analysis of very small organic molecular crystals and crystalline inorganic materials. Dynamical effects cause non-linear deviations from kinematical intensities that present issues in analysis. Here, a method continuous-rotation data is presented takes multiple scattering into account. refinements 12 compounds—ranging compounds to metal–organic frameworks materials—are compared, which new...

Accurate structure refinement from electron-diffraction data is not possible without taking the dynamical-diffraction effects into account. A complete three-dimensional model of can be obtained only a sufficiently set. In this work method presented for crystal by electron diffraction tomography, possibly combined with precession diffraction. The principle identical to that used in X-ray crystallography: are collected series small tilt steps around rotation axis, then intensities integrated...

The recently published method for the structure refinement from three-dimensional precession electron diffraction data using dynamical theory [Palatinus et al. (2015). Acta Cryst. A71, 235-244] has been applied to a set of experimental sets five different samples - Ni2Si, PrVO3, kaolinite, orthopyroxene and mayenite. were measured on instruments with variable angles. For each sample reliable reference was available. A large series tests revealed that provides models an average error in...

The charge-flipping algorithm (CFA) is a member of the diverse family dual-space iterative phasing algorithms. These algorithms use alternating modifications in direct and reciprocal space to find solution phase problem. current state-of-the-art CFA reviewed it put context related with relevance for crystallography. has found applications many crystallographic problems. principal various fields are described sections devoted routine structure solution, complex structures from powder...

Abstract The unprecedented bimetallic 2D coordination polymer {Fe[(Hg(SCN) 3 ) 2 ](4,4′‐bipy) } n exhibits a thermal high‐spin (HS)↔low‐spin (LS) staircase‐like conversion characterized by multi‐step dependence of the HS molar fraction γ . Between fully ( =1) and LS =0) phases, two steps associated with different ordering appear in terms spin‐state concentration waves (SSCW). On ≈0.5 step, periodic SSCW forms HS‐LS‐HS‐LS sequence. ≈0.34 4D superspace crystallography structural refinement...

Abstract Small‐pore zeolites such as chabazite (CHA) are excellent candidates for the selective separation of CO 2 ; however, current synthesis involves several steps and use organic structure‐directing agent (OSDA), increasing their cost energy requirements. We report small‐pore zeolite crystals (aluminosilicate) with CHA‐type framework structure by direct in a colloidal suspension containing mixture inorganic cations only (Na + , K Cs ). The location molecules host was revealed 3D electron...

One of the applications maximum-entropy method (MEM) in crystallography is reconstruction electron density from phased structure factors. Here application MEM to incommensurately modulated crystals and incommensurate composite considered. The computed directly superspace, where (3+d)-dimensional unit cell (d > 0) determined scattering data aperiodic crystals. Periodic = are treated as a special case general formalism. use symmetry discussed an efficient algorithm proposed for handling...

The charge-flipping structure-solution algorithm introduced by Oszlányi and Süto in 2004 has been adapted to accommodate powder diffraction data. In particular, a routine for repartitioning the intensities of overlapping reflections implemented within iterative procedure. This is done modifiying electron density map with histogram-matching algorithm, then using Fourier coefficients obtained from this repartition structure factor amplitudes each overlap group. effectiveness demonstrated five...

X-ray diffraction, dynamical mechanical analysis and infrared reflectivity studies revealed an antiferrodistortive phase transition in EuTiO3 ceramics. Near 300K the perovskite structure changes from cubic Pm-3m to tetragonal I4/mcm due antiphase tilting of oxygen octahedra along c axis (a0a0c- Glazer notation). The is analogous SrTiO3. However, some ceramics as well single crystals show different spectra bringing evidence a crystal structure. In such samples electron diffraction...

Electron diffraction is a unique tool for analysing the crystal structures of very small crystals. In particular, precession electron has been shown to be useful method ab initio structure solution. this work it demonstrated that data can also successfully used refinement, if dynamical theory calculation diffracted intensities. The on from three materials - silicon, orthopyroxene (Mg,Fe)(2)Si(2)O(6) and gallium-indium tin oxide (Ga,In)(4)Sn(2)O(10). atomic occupancies mixed crystallographic...

Determination of lattice parameters from 3D electron diffraction (3D ED) data measured in a transmission microscope is hampered by number effects that seriously limit the achievable accuracy. The distortion patterns optical elements often most severe problem. A thorough analysis experimental datasets shows that, addition to well known distortions, namely barrel-pincushion, spiral and elliptical, an additional distortion, dubbed parabolic, may be observed data. In precession data, parabolic...

We report on the latest advancements in Microcrystal Electron Diffraction (3D ED/MicroED), as discussed during a symposium at National Center for CryoEM Access and Training housed New York Structural Biology Center. This snapshot describes cutting-edge developments various facets of field identifies potential avenues continued progress. Key sections discuss instrumentation access, research applications small molecules biomacromolecules, data collection hardware software, reduction finally...

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 demonstrated successful eight known incommensurately modulated from experimental data. output the an electron density with symmetry P1. structure recovered locating positions operators and averaging over symmetry-related pixels. a accuracy result in detail on tetraphenylphosphonium...

Temperature-dependent x-ray diffraction of the low-dimensional spin 1/2 quantum magnet TiOCl shows that phase transition at T_{c2} = 90 K corresponds to a lowering lattice symmetry. Below T_{c1} 66 twofold superstructure develops, indicates formation spin-singlet pairs via direct exchange between neighboring Ti atoms, while role superexchange is found be negligible. thus identified as spin-Peierls system pure 1D chains atoms. The first-order character explained by competition structurally...

X-ray analysis reveals a zeolite structure in which 10-sided channels are periodically disrupted by 12-sided channels.