{"title":"The role of the coordination defect (CD) in the structures of anion-deficient, fluorite-related compounds.","authors":"D J M Bevan, Lisandra L Martin, Raymond L Martin","doi":"10.1107/S0108768112051105","DOIUrl":null,"url":null,"abstract":"<p><p>The various superstructure phases that occur with the anion-deficient compositions of binary oxides MO(2-x) with the fluorite structure as parent are explored here in terms of the original 'coordination defect' (or CD) concept in which each vacant oxygen site, □, is 'coordinated' by six O atoms thereby creating the octahedral 'structure-determining' entity [M(3.5)□O(6)]. It emerges that the structure and composition of each anion-deficient (polymorph) phase can be described in terms of crystallographic `motifs' which comprise sets of parallel coplanar polygons based on ½<210>(F) and ½<111>(F) CD linkages.</p>","PeriodicalId":7107,"journal":{"name":"Acta Crystallographica Section B-structural Science","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2013-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108768112051105","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta Crystallographica Section B-structural Science","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1107/S0108768112051105","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2013/1/19 0:00:00","PubModel":"Epub","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
Abstract
The various superstructure phases that occur with the anion-deficient compositions of binary oxides MO(2-x) with the fluorite structure as parent are explored here in terms of the original 'coordination defect' (or CD) concept in which each vacant oxygen site, □, is 'coordinated' by six O atoms thereby creating the octahedral 'structure-determining' entity [M(3.5)□O(6)]. It emerges that the structure and composition of each anion-deficient (polymorph) phase can be described in terms of crystallographic `motifs' which comprise sets of parallel coplanar polygons based on ½<210>(F) and ½<111>(F) CD linkages.
期刊介绍:
Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials publishes scientific articles related to the structural science of compounds and materials in the widest sense. Knowledge of the arrangements of atoms, including their temporal variations and dependencies on temperature and pressure, is often the key to understanding physical and chemical phenomena and is crucial for the design of new materials and supramolecular devices. Acta Crystallographica B is the forum for the publication of such contributions. Scientific developments based on experimental studies as well as those based on theoretical approaches, including crystal-structure prediction, structure-property relations and the use of databases of crystal structures, are published.