Related papers: On the crystal structure of lithium peroxide, Li2O…
The structures of the recently reported ordered perovskites SrLa(FeTi)O6 and BaLa(FeTi)O6 have been revisited using Rietveld analysis of the powder x-ray diffraction data. Our studies clearly show that earlier authors have incorrectly…
The crystal structure of Pb$_{10}$(PO$_4$)$_6$O, the proposed matrix for the potential room-temperature superconductor LK-99, Pb$_{10-x}$Cu$_x$(PO$_4$)$_6$O ($x = 0.9-1.0$), has been reinvestigated by single-crystal X-ray diffraction using…
We performed neutron powder diffraction experiments on lithium imide Li2NH, and have proposed a revised crystal structure model. Li2NH has a face-centered cubic structure with a partially occupied hydrogen site. Of the possible crystal…
The structure of a new member of the AxCoO2 x nH2O family (A=Li,Na,K) was determined by high-resolution synchrotron X-ray powder diffraction. Layered lithium cobalt oxide hydrate LixCoO2 x 2H2O crystallizes in a disordered monoclinic…
The crystal structure of Nb22O54 is reported for the first time, and the structure of orthorhombic Nb12O29 is reexamined, resolving previous ambiguities. Single crystal x-ray and electron diffraction were employed. These compounds were…
The behavior of identical particles interacting through the harmonic-repulsive pair potential has been studied in 3D using molecular dynamics simulations at a number of different densities. We found that at many densities, as the…
A percolation model is proposed to explain the structural phase transitions found in Li$_{1-x}$H$_x$IO$_3$ mixed crystals as a function of the concentration parameter $x$. The percolation thresholds are obtained from Monte Carlo simulations…
The orthorhombic crystal structure of the novel molecular-inorganic polymer $\mathrm{K_{2}SeO_{4}\cdot H_{2}SeO_{3}}$ was elucidated using single-crystal X-ray diffraction with MoK$\alpha$ radiation ($\lambda$= 0.71073 {\AA}), performed at…
We report the single-crystal X-ray analysis of the structure of the pyrochlore oxide superconductor KOs$_2$O$_6$. The structure was identified as the $\beta$-pyrochlore structure with space group $Fd\bar{3}m$ and lattice constant $a$ =…
A new superstructure of layered pristine LiNiO2 (LNO) was obtained optimizing a large supercell of the 166 space group, the one observed experimentally by XRD, and relaxing both cell parameters and internal positions. The crystal structure…
The effects of lithium absorption on the crystal structure and electronic properties of IrSi3, a binary silicide with a noncentrosymmetric crystal structure, were studied. X-ray and neutron diffraction experiments revealed that hexagonal…
Using first-principles density functional theory calculations, we investigate a family of stable two-dimensional crystals with chemical formula $A_2B_2$, where $A$ and $B$ belong to groups IV and V, respectively ($A$ = C, Si, Ge, Sn, Pb;…
A new modification of KOs2O6, the representative of a new structural type (Pearson symbol aP18, a=5.5668(1)A, b=6.4519(2)A, c=7.2356(2)A, space group P-1, no.2) was synthesized employing high pressure technique. Its structure was determined…
We analyze the geometrical background under which many Lie groups relevant to particle physics are endowed with a (possibly multiple) hexagonal structure. There are several groups appearing, either as special holonomy groups on the…
We report the synthesis and structural study of mixed oxides in the Ln2ScNbO7 series. New phases with Ln = Pr, Eu, Gd and Dy are obtained. All crystallize in the cubic pyrochlore structure type, space group F-d3m, with no Sc-Nb ordering on…
Lithium (Li) is a prototypical simple metal at ambient conditions, but exhibits remarkable changes in structural and electronic properties under compression. There has been intense debate about the structure of dense Li, and recent…
In the exploration of new osmium based double perovskites, Sr2FeOsO6 is a new insertion in the existing family. The polycrystalline compound has been prepared by solid state synthesis from the respective binary oxides. PXRD analysis shows…
A hexagonal structure of solid molecular hydrogen with $P6_122$ symmetry is calculated to be more stable below about 200 GPa than the monoclinic $C2/c$ structure identified previously as the best candidate for phase III. We find that the…
Structural changes of Li2C2 under pressure were studied by synchrotron x-ray diffraction in a diamond anvil cell under hydrostatic conditions and by using evolutionary search methodology for crystal structure prediction. We show that the…
The crystal structure of the layered, perovskite-related LaTiO_3.41 (La_5Ti_5O_{17+\delta}) has been studied by synchrotron powder x-ray diffraction under hydrostatic pressure up to 27 GPa (T = 295 K). The ambient-pressure phase was found…