AbstractHalide perovskites are potential candidates for their use in solar cells. In this study, an investigation of the structural, mechanical and electro-optical properties of $$\mathrm{ABX}_{3}$$ ABX 3 ($$A=K, Rb, Cs$$ A = K , R b , C s ; $$B=Ge, Sn, Pb$$ B = G e , S n , P b and $$X=Cl,Br,I$$ X = C l , B r , I ), under isosymmetric compression, is presented. All the calculations are performed with generalized gradient approximation schemes. We have examined the effect of cation and anion substitution on their overall properties.
AbstractDie Oxidation von weißem CsAgCl2 mit flüssigem Chlor führt zu schwarzem CsAgCl3. Guinier‐Simon‐Aufnahmen lassen auf Isotypie mit der Struktur des tetragonalen Cs2Au2Cl6. schließen. Somit liegt eine gemischtvalente Silber(I, III)‐ Verbindung, das erste ternäre Chlorid mit Silber in der Oxidationsstufe +3, vor (I4/mmm, a = 722,23(12) pm, c = 1082,4(4) pm). Bei der thermischen Zersetzung von CsAgCl3 entsteht die Hochtemperaturmodifikation von CsAgCl2.
AbstractCrystals of Cs2Sb SbCl6Sb are diamagnetic and have a cubic structure of the antifluorite type. These facts may be explained either in terms of statistical disorder between Sb(III) and Sb(V) or in terms of electron exchange between SbCl and SbCl. A calculation is presented of the exchange interaction between the nearest SbCl complexes. The exchange integral £ is taken in form £ = (Es − Et)/2 where Es and Et are energies of singlet and triplet states. It is established that CI atoms mainly contribute to the exchange interaction. Sign and value of the exchange integral correspond to an antiferromagnetically ordered state in Cs2SbCl6 at room temperature.
Ibrahim Olanrewaju Alade, Ismail Adewale Olumegbon, Aliyu Bagudu
Lattice constant mismatch between materials affects the quality of thin film fabrication. For this reason, lattice constants information is vital in the design of materials for technological applications. The determination of lattice constants via experimental analysis is relatively expensive and laborious. As a result, several linear empirical models have been proposed to predict the lattice constant of crystal structures. However, the accuracies of these models are limited partly due to their failure to account for nonlinearity in the atomic parameters-lattice constant relationship. Machine learning techniques have shown excellent ability to deal with nonlinear problems in many areas of materials science; hence, they are considered suitable computation tools to study the crystal structure of materials. In this contribution, we developed a support vector regression (SVR) model to predict the lattice constant of cubic crystals of the form A2XY6 (A = K, Cs, Rb, TI; X = tetravalent cation; and Y = F, Cl, Br, I). The SVR algorithm uses the ionic radii and electronegativities data of the constituent elements of A2XY6 cubic crystals as model inputs. The robustness of the proposed model was demonstrated by comparing our result with an existing linear model based on 26 cubic crystal samples. The result revealed a total relative deviation of 1.757 and 2.704 for the SVR model and the existing linear equation, respectively. This result proves that the SVR model has a huge potential in the search for new materials for different applications.
Palanisamy Uma Maheswari, Renuga Duraisamy, Murugesan Kanagavel
et al.
Background:The ligand Hpyramol is a redox active, which on coordination with Cu(II) cleaves DNA without any added reductant. Another ligand phendione is known for its wide application towards anticancer activities. We combined the ligands with CuCl2 to have an intercalation moiety and a redox active ligand in participation towards telomere DNA cleavage and anticancer activity.Objective:In this study, our aim is to interact it with Human telomere DNA and to see their effects on cancer cells.Methods:The complex [Cu(L)(L’)Cl] has interacted with the human telomere DNA sequence (TTAGGG), HTelo20. The HTelo20 was stabilized under both parallel and antiparallel G-quadruplex conformations and the complex [Cu(L)(L’)Cl] has interacted followed by circular dichroism spectroscopy and gel electrophoresis.Results:The parallel G-quadruplex and randomly coiled conformations of HTelo20 were easily cleaved than the anti-parallel G-quadruplex conformation. The nature of DNA cleavage was found to be oxidative rather hydrolytic. The formation of phenoxyl radical species under electrochemical and controlled potential electrolysis conditions by the complex [Cu(L)(L’)Cl] proves the possibility of oxidative nature of DNA cleavage. The comet assay also proves the DNA cleavage induced by the complex [Cu(L)(L’)Cl] inside the nucleus of HeLa cancer cells.Conclusion:The complex [Cu(L)(L’)Cl] was tested for anticancer activity, induced by ROS and DNA cleavage. The IC50 values resulted in nanomolar concentrations with selected cancer cell lines. Relatively the Cu complex shows less toxicity with the normal cell line L132.