{"title":"The polar phase of Li2Ge4O9 at 298, 150 and 90 K.","authors":"Günther J Redhammer, Gerold Tippelt","doi":"10.1107/S0108270113025110","DOIUrl":null,"url":null,"abstract":"<p><p>Dilithium tetragermanate is orthorhombic, space group P2(1)ca, at 298 K, and is thus in a polar and probably a ferroelectric state. The structure contains two independent Li, four Ge and nine O atoms, all on general positions with site symmetry 1. Three tetrahedrally coordinated Ge positions form crumpled crankshaft-like chains, forming sheets within the ac plane, and these are interconnected by the fourth, octahedrally coordinated, Ge sites along the b direction. The GeO4 tetrahedra and GeO6 octahedra form a three-dimensional framework containing two different cavities, hosting the two 4+1-coordinated Li sites. Cooling to 90 K does not alter the space-group symmetry; the tetrahedral chains behave as a rigid unit and changes occur mainly within the Li coordination spheres.</p>","PeriodicalId":7368,"journal":{"name":"Acta crystallographica. Section C, Crystal structure communications","volume":null,"pages":null},"PeriodicalIF":0.8000,"publicationDate":"2013-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1107/S0108270113025110","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Acta crystallographica. Section C, Crystal structure communications","FirstCategoryId":"92","ListUrlMain":"https://doi.org/10.1107/S0108270113025110","RegionNum":4,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2013/9/28 0:00:00","PubModel":"Epub","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
Dilithium tetragermanate is orthorhombic, space group P2(1)ca, at 298 K, and is thus in a polar and probably a ferroelectric state. The structure contains two independent Li, four Ge and nine O atoms, all on general positions with site symmetry 1. Three tetrahedrally coordinated Ge positions form crumpled crankshaft-like chains, forming sheets within the ac plane, and these are interconnected by the fourth, octahedrally coordinated, Ge sites along the b direction. The GeO4 tetrahedra and GeO6 octahedra form a three-dimensional framework containing two different cavities, hosting the two 4+1-coordinated Li sites. Cooling to 90 K does not alter the space-group symmetry; the tetrahedral chains behave as a rigid unit and changes occur mainly within the Li coordination spheres.
期刊介绍:
Acta Crystallographica Section C: Structural Chemistry is continuing its transition to a journal that publishes exciting science with structural content, in particular, important results relating to the chemical sciences. Section C is the journal of choice for the rapid publication of articles that highlight interesting research facilitated by the determination, calculation or analysis of structures of any type, other than macromolecular structures. Articles that emphasize the science and the outcomes that were enabled by the study are particularly welcomed. Authors are encouraged to include mainstream science in their papers, thereby producing manuscripts that are substantial scientific well-rounded contributions that appeal to a broad community of readers and increase the profile of the authors.