[18] Photographic science and microdensitometry in X-ray diffraction data collection

1985 ◽  
pp. 199-211
Author(s):  
Michael Elder
Keyword(s):  
Data Collection ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray

Masquerade: removing non-sample scattering from integrated reflection intensities

2012 ◽  
Vol 45 (2) ◽  
pp. 292-298 ◽  
Author(s):  
J. A. Coome ◽  
A. E. Goeta ◽  
J. A. K. Howard ◽  
M. R. Probert
Keyword(s):  
Data Collection ◽  
Diffraction Data ◽  
Low Temperatures ◽  
Test Case ◽  
X Rays ◽  
Atmospheric Conditions ◽  
X Ray Diffraction ◽  
New Approach ◽  
X Ray ◽  
Internal Agreement

X-ray diffraction experiments at very low temperatures require samples to be isolated from atmospheric conditions and held under vacuum. These conditions are usually maintainedviathe use of beryllium chambers, which also scatter X-rays, causing unwanted contamination of the sample's diffraction pattern. The removal of this contamination requires novel data-collection and processing procedures to be employed. Herein a new approach is described, which utilizes the differences in origin of scattering vectors from the sample and the beryllium to eliminate non-sample scattering. The programMasqueradehas been written to remove contaminated regions of the diffraction data from the processing programs. Coupled with experiments at different detector distances, it allows for the acquisition of decontaminated data. Studies of several single crystals have shown that this approach increases data quality, highlighted by the improvement in internal agreement factor with the test case of cytidine presented herein.

scholarly journals The finer things in X-ray diffraction data collection

1999 ◽  
Vol 55 (10) ◽  
pp. 1718-1725 ◽  
Author(s):  
J. W. Pflugrath
Keyword(s):  
Data Collection ◽  
Diffraction Data ◽  
Rotation Angle ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Software Suite ◽  
X Ray ◽  
Position Sensitive ◽  
X Ray Background ◽  
Position Sensitive Detectors

X-ray diffraction images from two-dimensional position-sensitive detectors can be characterized as thick or thin, depending on whether the rotation-angle increment per image is greater than or less than the crystal mosaicity, respectively. The expectations and consequences of the processing of thick and thin images in terms of spatial overlap, saturated pixels, X-ray background andI/σ(I) are discussed. Thed*TREKsoftware suite for processing diffraction images is briefly introduced, and results fromd*TREKare compared with those from another popular package.

The structure of cubic MOF [{Ca(H2O)6}{CaGd(oxydiacetate)3}2].4H2O. A comparison between structural models obtained from Rietveld refinement of conventional and synchrotron X-ray powder diffraction data and standard refinement of single-crystal X-ray diffraction data

2012 ◽  
Vol 27 (4) ◽  
pp. 232-242 ◽  
Author(s):  
Leopoldo Suescun ◽  
Jun Wang ◽  
Ricardo Faccio ◽  
Guzmán Peinado ◽  
Julia Torres ◽  
...  
Keyword(s):  
Data Collection ◽  
Single Crystal ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Structural Models ◽  
Initial Time ◽  
High Symmetry ◽  
Powder Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray

The structure of the metal–organic framework (MOF) compound [{Ca(H2O)6}{CaGd(oxydiacetate)3}2]·4H2O was determined by single-crystal X-ray diffraction and refined using conventional single-crystal X-ray diffraction data. In addition, the structure was refined using powder diffraction data collected from two sources, a conventional X-ray diffractometer in Bragg–Brentano geometry and a 12-detector high resolution synchrotron-based diffractometer in transmission geometry. Data from the latter were processed in three different ways to account for crystalline decay or radiation damage. One dataset was obtained by averaging the multiple detector patterns, another dataset was obtained by cutting the non-overlapping portions of each detector to consider only the first few minutes of data collection and a dose-corrected dataset was obtained by fitting the independent peaks in every dataset and extrapolating the intensity and peak position to the initial time of data collection or to zero-absorbed dose. The compared structural models obtained show that special processing of powder diffraction data produced a much accurate model, close to the single-crystal-based model for this particular compound with heavy atoms in high symmetry positions that do not contribute to a significant number of diffraction intensities.

scholarly journals Use of the Bruker AXS SMART BREEZE™ System for Macromolecular X-ray Data Collection

2016 ◽  
Vol 13 (4) ◽  
Author(s):  
Christiana Standle ◽  
Blake Overson ◽  
Cody Black ◽  
Guizella Rocabado ◽  
Bruce Howard
Keyword(s):  
Data Collection ◽  
Diffraction Data ◽  
Undergraduate Research ◽  
Inorganic Compounds ◽  
Copper Anode ◽  
X Ray Diffraction ◽  
Small Unit ◽  
X Ray ◽  
Unit Cells ◽  
Protein Enzyme

The Bruker AXS SMART BREEZE™ system is a single-crystal X-ray diffractometer designed to collect data from crystals of small organic or inorganic compounds. It is typically equipped with a Molybdenum-anode sealed tube to facilitate data collection from small unit cells. We recently acquired this system, but chose to have it installed with a copper-anode sealed tube with the hope of using it to collect data from larger unit cells such as those found in crystals of proteins or other macromolecules. This is the first and only BREEZE™ system installed by Bruker AXS with a copper-anode to date. Here we show that this system is capable of efficiently collecting quality X-ray diffraction data from crystals of the enzymes lysozyme and xylanase. This capability to collect diffraction data from both macromolecular and small-molecule crystals greatly expands the scope of undergraduate research projects that can be addressed using this instrument. KEYWORDS: X-ray; Diffraction; Crystallography; Diffractometer; Protein; Enzyme; Crystal; Structure

scholarly journals Data-collection strategies

1999 ◽  
Vol 55 (10) ◽  
pp. 1703-1717 ◽  
Author(s):  
Zbigniew Dauter
Keyword(s):  
Data Collection ◽  
Information Content ◽  
Diffraction Data ◽  
Optimal Strategy ◽  
Reciprocal Lattice ◽  
Experimental Setup ◽  
X Ray Diffraction ◽  
X Ray ◽  
Factors Influencing ◽  
Collection Strategies

The optimal strategy for collecting X-ray diffraction data from macromolecular crystals is discussed. Two kinds of factors influencing the completeness of data are considered. The first are geometric, arising from the symmetry of the reciprocal lattice and from the experimental setup; they affect quantitatively the completeness of the measured set of reflections. The second concern the quality, or information content, of the recorded intensities of these measured reflections.

scholarly journals Visualisation of membrane protein crystals using X-ray imaging

2014 ◽  
Vol 70 (a1) ◽  
pp. C351-C351
Author(s):  
Anna Warren ◽  
Wes Armour ◽  
Danny Axford ◽  
Mark Basham ◽  
Thomas Connolley ◽  
...  
Keyword(s):  
Data Collection ◽  
Diffraction Data ◽  
Cubic Phase ◽  
Informed Decision Making ◽  
Macromolecular Crystallography ◽  
X Ray Diffraction ◽  
Shape Estimation ◽  
X Ray ◽  
Raster Scanning ◽  
X Ray Imaging

The focus in macromolecular crystallography is moving towards even more challenging target proteins that often crystallise on much smaller scales and are frequently mounted in opaque or highly refractive materials.[1,2] It is therefore essential that X-ray beamline technology develops in parallel to accommodate such difficult samples. In this poster the use of X-ray microradiography and microtomography is reported as a tool for crystal visualisation, location and characterization on the macromolecular crystallography beamlines at the Diamond Light Source. The technique is particularly useful for microcrystals, and crystals mounted in opaque materials such as lipidic cubic phase. X-ray diffraction raster scanning can be used in combination with radiography to allow informed decision-making at the beamline prior to diffraction data collection. It is demonstrated that the X-ray dose required for a full tomography measurement is similar to a diffraction grid scan. However, for sample location and shape estimation alone, just a few radiographic projections may be required; hence reducing the dose the crystals will be exposed to prior to the diffraction data collection.[3]

scholarly journals Some notes on choices in data collection

1999 ◽  
Vol 55 (10) ◽  
pp. 1771-1772 ◽  
Author(s):  
Philip R. Evans
Keyword(s):  
Data Collection ◽  
Exposure Time ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
X Ray

Collecting optimum X-ray diffraction data involves a number of choices and compromises, including choice of crystal, source, rotation range, exposure time and programs for integration and scaling. This paper presents a series of questions which should be considered in planning a data-collection experiment.

Condensation-free X-ray diffraction data collection with capillaries at 277 K

1999 ◽  
Vol 32 (1) ◽  
pp. 134-135
Author(s):  
Daniel Lim ◽  
Qilu Ye ◽  
Zongchao Jia
Keyword(s):  
Data Collection ◽  
Diffraction Data ◽  
Temperature Gradients ◽  
X Ray Diffraction ◽  
X Ray

Crystallization at 277 K is routinely practiced in most crystallography laboratories. Data collection from such crystals at this temperature has been facilitated by the widespread use of versatile cryocooling devices capable of maintaining crystals at cryogenic to near room temperatures. However, temperature gradients can potentially develop along a capillary cooled by a gas stream, which may result in condensation around the crystal. A convenient protocol has been developed and used successfully to prevent this problem. By the placement of oil plugs close to both sides of the crystal, the enclosed airspace is kept free of condensation, even while the capillary is cooled for extended periods of time by a gas stream flowing at an angle to the capillary. This technique eliminates the need to work with very short capillaries and can be implemented without modification to an existing cryostat configuration.

Sign in / Sign up

Export Citation Format

Share Document