Ángel Gómez Vegas

Learn More
The generation and maintenance of subcellular organization in bacteria is critical for many cell processes and properties, including growth, structural integrity and, in pathogens, virulence. Here, we investigate the mechanisms by which the virulence protein IcsA (VirG) is distributed on the bacterial surface to promote efficient transmission of the(More)
The structural behavior of the antifluorite Na(2)S, disodium sulfide, has been studied under pressure up to 22 GPa by in situ synchrotron X-ray diffraction experiments in a diamond anvil cell at room temperature. At approximately 7 GPa, Na(2)S undergoes a first phase transition to the orthorhombic anticotunnite (PbCl(2)) structure (Pnma, Z = 4). The lattice(More)
We introduce and discuss an interpretative model of the structure and bonding of inorganic crystals containing metallic elements. The central idea is the conception of the crystal structure of such an inorganic compound as a metallic matrix whose geometric and electronic structures govern the formation and localization of the anions in the lattice. This is(More)
The bixbyite structure (Mn(2)O(3)) (Ia3) is often described as a distorted face-centered cubic (f.c.c.) array of Mn atoms, with O atoms occupying 3/4 of the tetrahedral holes. The empty M(4) tetrahedra are centred at 16c. In anti-bixbyite structures (Mg(3)N(2)), cation vacancies are centred in empty N(4) tetrahedra. If 16 hypothetical atoms were located at(More)
As in SiO2 which, at high pressures, undergoes the alpha-quartz-->stishovite transition, GaAsO4 transforms into a dirutile structure at 9 GPa and 1173 K. In 2002, a new GaAsO4 polymorph was found by quenching the compound from 6 GPa and 1273 K to ambient conditions. The powder diagram was indexed on the basis of a hexagonal cell (a=8.2033, c=4.3941 A,(More)
The high-pressure behaviour of dirubidium sulfide, Rb(2)S, with antifluorite-type structure under room conditions (space group Fm ̄3m) has been studied up to 8 GPa at room temperature using angle-dispersive X-ray powder diffraction in a diamond-anvil cell (DAC). X-ray measurements have allowed us to completely characterize two phase transitions upon(More)
Theoretical calculations of the electron-localization function show that, at the volumes of the two CaO phases (rocksalt and CsCl type), the parent Ca structures (fcc: face-centred cubic and sc: simple cubic, respectively) exhibit charge concentration zones which coincide with the positions occupied by the O atoms in their oxides. Similar features, also(More)
The structures of 94 ternary aluminates are reinterpreted on the basis of the Zintl-Klemm concept and Pearson's generalized octet rule. In aluminates of highly electropositive metals such as alkali, alkaline-earth and rare-earth metals, the Al atoms form three-dimensional skeleta which can be interpreted as if the Al atoms were behaving as Zintl polyanions,(More)
More than 100 examples are provided of the structural identity between the cation arrays in oxides and their corresponding alloys (binary compounds). Halides and halogenates, sulfides and sulfites and/or sulfates, selenides and selenates, phosphides and phosphates show this behaviour. In some cases, the structure of the cation subarray corresponds to the(More)