scholarly journals Precession electron diffraction – a topical review

IUCrJ ◽  
2015 ◽  
Vol 2 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Paul A. Midgley ◽  
Alexander S. Eggeman
Keyword(s):  
Electron Diffraction ◽  
Method Development ◽  
Scanning System ◽  
Local Orientation ◽  
Electron Crystallography ◽  
X Ray ◽  
X Ray Crystallography ◽  
Topical Review ◽  
Crystal Texture ◽  
Precession Electron Diffraction

In the 20 years since precession electron diffraction (PED) was introduced, it has grown from a little-known niche technique to one that is seen as a cornerstone of electron crystallography. It is now used primarily in two ways. The first is to determine crystal structures, to identify lattice parameters and symmetry, and ultimately to solve the atomic structureab initio. The second is, through connection with the microscope scanning system, to map the local orientation of the specimen to investigate crystal texture, rotation and strain at the nanometre scale. This topical review brings the reader up to date, highlighting recent successes using PED and providing some pointers to the future in terms of method development and how the technique can meet some of the needs of the X-ray crystallography community. Complementary electron techniques are also discussed, together with how a synergy of methods may provide the best approach to electron-based structure analysis.

scholarly journals Closing the gap between electron and X-ray crystallography

2015 ◽  
Vol 71 (6) ◽  
pp. 737-739 ◽  
Author(s):  
Enrico Mugnaioli
Keyword(s):  
Electron Diffraction ◽  
Structure Characterization ◽  
Diffraction Tomography ◽  
X Rays ◽  
Electron Crystallography ◽  
X Ray ◽  
X Ray Crystallography ◽  
Closing The Gap ◽  
Refinement Algorithm

The development of a proper refinement algorithm that takes into account dynamical scattering guarantees, for electron crystallography, results approaching X-rays in terms of precision, accuracy and reliability. The combination of such dynamical refinement and electron diffraction tomography establishes a complete pathway for the structure characterization of single sub-micrometric crystals.

The structure of nano-twinned rhombohedral YCuO2.66 solved by electron crystallography

2019 ◽  
Vol 75 (1) ◽  
pp. 107-112 ◽  
Author(s):  
Holger Klein ◽  
V. Ovidiu Garlea ◽  
Céline Darie ◽  
Pierre Bordet
Keyword(s):  
Electron Diffraction ◽  
Two Dimensions ◽  
Electron Diffraction Data ◽  
Electron Crystallography ◽  
One Dimensional ◽  
X Ray ◽  
Spin Interactions ◽  
Structure Solution ◽  
Precession Electron Diffraction ◽  
Frustrated Spin

In the search for frustrated spin interactions, a YCuO2.66 phase has been synthesized by a treatment under oxygen pressure of YCuO2.5. X-ray powder diffraction and electron diffraction studies have been conducted. Electron diffraction shows that the sample is twinned on a 10 nm scale. Precession electron diffraction data obtained from a twinned crystal was treated in order to obtain intensities corresponding to only one of the orientations of the twins. From this data a structure solution was obtained where, as in YCuO2.5, the Cu atoms form triangular planes. The Cu atoms are linked in two dimensions by oxygen atoms in the present structure whereas in YCuO2.5 they are only linked in one-dimensional chains.

scholarly journals Structural Analysis of Ligand Protected Smaller Metallic Nanocrystals by Atomic Pair Distribution Function Under Precession Electron Diffraction

2019 ◽  
Author(s):  
M. Mozammel Hoque ◽  
Sandra Vergara ◽  
Partha P. Das ◽  
Daniel Ugarte ◽  
Ulises Santiago ◽  
...  
Keyword(s):  
Distribution Function ◽  
Electron Diffraction ◽  
Pair Distribution Function ◽  
Electron Diffraction Data ◽  
Face Centered Cubic ◽  
X Ray ◽  
Atomic Pair Distribution Function ◽  
Atomic Pair ◽  
Pdf Analysis ◽  
Precession Electron Diffraction

Atomic pair distribution function (PDF) analysis has been widely used to investigate nanocrystalline and structurally disordered materials. Experimental PDFs retrieved from electron diffraction (ePDF) in transmission electron microscopy (TEM) represent an attractive alternative to traditional PDF obtained from synchrotron X-ray sources, when employed on minute samples. Nonetheless, the inelastic scattering produced by the large dynamical effects of electron diffraction may obscure the interpretation of ePDF. In the present work, precession electron diffraction (PED-TEM) has been employed to obtain the ePDF of two different sub-monolayer samples ––lipoic acid protected (~ 4.5 nm) and hexanethiolated(~ 4.2 nm, ~ 400-kDa core mass) gold nanoparticles­­––randomly oriented and measured at both liquid-nitrogen and room temperatures, with high dynamic-range detection of a CMOS camera. The electron diffraction data were processed to obtain ePDFs which were subsequently compared with PDF of different ideal structure-models. The results demonstrate that the PED-ePDF data is sensitive to different crystalline structures such as monocrystalline (truncated octahedra) versus multiply-twinned (decahedra, icosahedra) structuresof the face-centered cubic gold lattice. The results indicate that PED reduces the residual from 46% to 29%; in addition, the combination of PED and low temperature further reduced the residual to 23%, which is comparable to X-ray PDF analysis. Furthermore, the inclusion of PED resulted in a better estimation of the coordination number from ePDF. To the best of our knowledge, the precessed electron-beam technique (PED) has not been previously applied to nanoparticles for analysis by the ePDF method.

scholarly journals Serial Electron Diffraction Data Processing With diffractem and CrystFEL

2021 ◽  
Vol 8 ◽  
Author(s):  
Robert Bücker ◽  
Pascal Hogan-Lamarre ◽  
R. J. Dwayne Miller
Keyword(s):  
Electron Diffraction ◽  
Data Processing ◽  
Three Dimensional ◽  
Electron Diffraction Data ◽  
New Techniques ◽  
X Ray ◽  
X Ray Crystallography ◽  
Level Of Automation ◽  
Rotation Method ◽  
High Level

Serial electron diffraction (SerialED) is an emerging technique, which applies the snapshot data-collection mode of serial X-ray crystallography to three-dimensional electron diffraction (3D Electron Diffraction), forgoing the conventional rotation method. Similarly to serial X-ray crystallography, this approach leads to almost complete absence of radiation damage effects even for the most sensitive samples, and allows for a high level of automation. However, SerialED also necessitates new techniques of data processing, which combine existing pipelines for rotation electron diffraction and serial X-ray crystallography with some more particular solutions for challenges arising in SerialED specifically. Here, we introduce our analysis pipeline for SerialED data, and its implementation using the CrystFEL and diffractem program packages. Detailed examples are provided in extensive supplementary code.

scholarly journals Combining electron crystallography and X-ray crystallography to study the MlotiK1 cyclic nucleotide-regulated potassium channel

2009 ◽  
Vol 167 (3) ◽  
pp. 220-226 ◽  
Author(s):  
Gina M. Clayton ◽  
Steve G. Aller ◽  
Jimin Wang ◽  
Vinzenz Unger ◽  
João H. Morais-Cabral
Keyword(s):  
Potassium Channel ◽  
Cyclic Nucleotide ◽  
Electron Crystallography ◽  
X Ray ◽  
X Ray Crystallography

scholarly journals Comparing serial X-ray crystallography and microcrystal electron diffraction (MicroED) as methods for routine structure determination from small macromolecular crystals

IUCrJ ◽  
2020 ◽  
Vol 7 (2) ◽  
pp. 306-323 ◽  
Author(s):  
Alexander M. Wolff ◽  
Iris D. Young ◽  
Raymond G. Sierra ◽  
Aaron S. Brewster ◽  
Michael W. Martynowycz ◽  
...  
Keyword(s):  
Electron Diffraction ◽  
Structural Information ◽  
Biological Macromolecules ◽  
Structural Studies ◽  
Macromolecular Crystallography ◽  
Delivery Methods ◽  
X Ray ◽  
X Ray Crystallography ◽  
Physical Conditions ◽  
Serial Crystallography

Innovative new crystallographic methods are facilitating structural studies from ever smaller crystals of biological macromolecules. In particular, serial X-ray crystallography and microcrystal electron diffraction (MicroED) have emerged as useful methods for obtaining structural information from crystals on the nanometre to micrometre scale. Despite the utility of these methods, their implementation can often be difficult, as they present many challenges that are not encountered in traditional macromolecular crystallography experiments. Here, XFEL serial crystallography experiments and MicroED experiments using batch-grown microcrystals of the enzyme cyclophilin A are described. The results provide a roadmap for researchers hoping to design macromolecular microcrystallography experiments, and they highlight the strengths and weaknesses of the two methods. Specifically, we focus on how the different physical conditions imposed by the sample-preparation and delivery methods required for each type of experiment affect the crystal structure of the enzyme.

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