Richardson, IG (2013) The importance of proper crystal-chemical and geometrical reasoning demonstrated using layered single and double hydroxides. Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 69 (2). 150 - 162. ISSN 2052-5206
Abstract
Atomistic modelling techniques and Rietveld refinement of X-ray powder diffraction data are widely used but often result in crystal structures that are not realistic, presumably because the authors neglect to check the crystal-chemical plausibility of their structure. The purpose of this paper is to reinforce the importance and utility of proper crystal-chemical and geometrical reasoning in structural studies. It is achieved by using such reasoning to generate new yet fundamental information about layered double hydroxides (LDH), a large, much-studied family of compounds. LDH phases are derived from layered single hydroxides by the substitution of a fraction (x) of the divalent cations by trivalent. Equations are derived that enable calculation of x from the a parameter of the unit cell and vice versa, which can be expected to be of widespread utility as a sanity test for extant and future structure determinations and computer simulation studies. The phase at x = 0 is shown to be an α form of divalent metal hydroxide rather than the β polymorph. Crystal-chemically sensible model structures are provided for β-Zn(OH) and Ni- and Mg-based carbonate LDH phases that have any trivalent cation and any value of x, including x = 0 [i.e. for α-M(OH)mHO phases]. © 2013 International Union of Crystallography Printed in Singapore - all rights reserved.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © International Union of Crystallography. This open-access article is distributed under the terms of the Creative Commons Attribution Licence http://creativecommons.org/licenses/by/2.0/uk/legalcode, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited. |
Keywords: | Atomistic modelling techniques; X-ray powder diffraction; layered double hydroxides |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Civil Engineering (Leeds) > Institute for Resilient Infrastructure (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 19 May 2014 08:59 |
Last Modified: | 16 Nov 2016 09:17 |
Published Version: | http://dx.doi.org/10.1107/S205251921300376X |
Status: | Published |
Publisher: | International Union of Crystallography |
Refereed: | Yes |
Identification Number: | 10.1107/S205251921300376X |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:76178 |