Mackinawite,tetragonal FeS, has been synthesised by reacting iron with Na2S solutions. A Rietveld structure refinement of X-ray powder diffractipn data, recorded using X-rays monochromated from synchrotron radiationwith a wavelength of 0.6023 A, has been performed. The structure has been refined in the tetragonal sJ'.!lcegroup, P4/nmm, and has the following cell parameters: a = 3.6735(4), c = 5...

We present the results of a plane wave based density functional study of the structure and properties of tetragonal zirconia in the range of pressures from 0 to 50 GPa. We predict a transition to a fluorite-type cubic structure at 37 GPa which is likely to be of a soft mode origin and is accompanied by a power law decrease of the frequency of the Raman-active A(1g) mode. A detailed study of the...

A study of the magnetic and structural properties of the double perovskite Ba2GdMoO6 has been performed. The crystal structure distorts from the ideal cubic (Fm3m) structure to the tetragonal space group I4/m at 220 K, before undergoing a second distortion to a triclinic system (I1) at 80 K. The phase transition to triclinic symmetry is also evident in magnetic susceptibility measurements. The ...

It was shown that the structure and particle size of zirconia nanoparticles has been controlled through the homogeneous precipitation process by using templates. Hexamine as the template led to ZrO2 nanoparticles with tetragonal structure, whereas coffee extract favored monoclinic structures. Field Emission Scanning electron microscopy (FeSEM), Transmission electron microscopy (TEM) measurement...

The bifunctional diaminohydroxyphosphoribosylaminopyrimidine deaminase/5-amino-6-(5-phosphoribosylamino)uracil reductase (RibD) represents a potential antibacterial drug target. The structure of recombinant Acinetobacter baumannii RibD is reported in orthorhombic and tetragonal crystal forms at 2.2 and 2.0 Å resolution, respectively. Comparisons with orthologous structures in the Protein Data B...