Crystal structure and formula revision of deliensite, Fe[(UO2)2(SO4)2(OH)2](H2O)7

AbstractThe crystal structure of deliensite, Fe[(UO2)2(SO4)2(OH)2](H2O)7, was solved by direct methods and refined toR1= 6.24% for 5211 unique observed reflections [Iobs&gt; 3σ(I)], on a crystal that was found to consist of rotational and inversion (merohedral) twins, from Jeroným mine, Abertamy in the Czech Republic. The presence of four twin domains was taken into account in the refinement. The structure is orthorhombic, space groupPnn2, with unit-cell parametersa= 15.8514(9),b= 16.2478(7),c= 6.8943(3) Å,V= 1775.6(1) Å3andZ= 4. The crystal structure of deliensite contains uranyl-sulfate sheets with a phosphuranylite topology, consisting of dimers of edge-sharing uranyl pentagonal bipyramids linked by corner-sharing with sulfate tetrahedra. The sheets lie in the (100) plane and are decorated by [Fe2+O(H2O)5] octahedra; two weakly bonded H2O molecules are present in the interlayer. The [Fe2+O(H2O)5] octahedron is linked directly to the sheet via the uranyl oxygen atom. Adjacent sheets are linked by hydrogen bonds only. The sheet topology and geometrical isomerism is discussed and a comparison of the composition obtained from electron-probe microanalysis, powder-diffraction data, Raman and infrared spectra of deliensite samples from Mas d'Alary, Lodève, France; L'Ecarpière mine, Gétigné, France; and several localities at Jáchymov, Western Bohemia, Czech Republic is made.</jats:p

Vertical knowledge transfer in Czech organizations

For organizations the losing key employees is the greatest threat; if the organizations lose the key workers, they cannot use their premises, data, information and other resources. The article aims at evaluation of the level of vertical knowledge transfer in organizations in the Czech Republic. The partial goals of this article are to determine dependencies between the examined qualitative features. The article has been drawn up using scientific methods, in particular logical methods, such as analysis, synthesis, induction, deduction and comparison. The results were obtained from longitudinal quantitative research in organizations in the Czech Republic from 2010 to 2014. The article identifies the factors affecting vertical knowledge transfer and presents a method of eliminating the risk of losing key knowledge workers. Vertical knowledge transfer is a new supporting factor of organizations’ productivity and business continuity