On the significance of Bragg reflections

Acta Crystallographica. Section A, Foundations of Crystallography
Mads Ry Vogel JørgensenBo Brummerstedt Iversen

Abstract

Recently Henn & Meindl [Acta Cryst. (2010), A66, 676-684] examined the significance of Bragg diffraction data through the descriptor W = (I(1/2))/(σ(I)). In the Poisson limit for the intensity errors W equals unity, but any kind of data processing (background subtraction, integration, scaling, absorption correction, Lorentz and polarization correction etc.) introduces additional error as well as remaining systematic errors and thus the significance of processed Bragg diffraction data is expected to be below the Poisson limit (W(Bragg) < 1). Curiously, it was observed by Henn & Meindl for several data sets that W(Bragg) had values larger than one. In the present study this is shown to be an artefact due to the neglect of a data scale factor applied to the standard uncertainties, and corrected values of W(Bragg) applied to Bragg data on an absolute scale are presented, which are all smaller than unity. Furthermore, the error estimation models employed by two commonly used data-processing programs {SADABS (Bruker AXS Inc., Madison, Wisconsin, USA) and SORTAV [Blessing (1997). J. Appl. Cryst. 30, 421-426]} are examined. It is shown that the empirical error model in SADABS very significantly lowers the significance of the Bragg data...Continue Reading

References

Dec 22, 2005·Acta Crystallographica. Section D, Biological Crystallography·Philip Evans
Jun 3, 2010·Acta Crystallographica. Section D, Biological Crystallography·Kay Diederichs
Oct 22, 2010·Acta Crystallographica. Section A, Foundations of Crystallography·Julian Henn, Kathrin Meindl
Dec 1, 2010·Journal of Applied Crystallography·David Waterman, Gwyndaf Evans

❮ Previous
Next ❯

Citations

Jun 20, 2015·Journal of Applied Crystallography·Lennard KrauseDietmar Stalke
Oct 9, 2014·IUCrJ·Mads R V JørgensenBo B Iversen
Mar 1, 2018·Chemistry : a European Journal·Alessandro GenoniSimon Grabowsky
Aug 2, 2017·Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials·Kasper TolborgBo B Iversen
Aug 2, 2017·Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials·Regine Herbst-Irmer, Dietmar Stalke
Jul 21, 2020·Journal of Applied Crystallography·Lennard KrauseJacob Overgaard

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.

Related Papers

Acta Crystallographica. Section E, Structure Reports Online
Mei LuoJing-Cheng Zhang
Acta Crystallographica. Section E, Structure Reports Online
Zohreh DerikvandJafar Attar Gharamaleki
Acta Crystallographica. Section E, Structure Reports Online
Hai-Wei Kuai, Xiao-Chun Cheng
© 2022 Meta ULC. All rights reserved