Phases of the iron-oxygen binary system are significant to most scientific disciplines, directly affecting planetary evolution, life, and technology. Iron oxides have unique electronic properties strongly interact with environment, particularly through redox reactions. The phase diagram therefore has been among thoroughly investigated, yet it still holds striking findings. Here, we report discovery an iron oxide formula Fe(4)O(5), synthesized at high pressure temperature. previously...

The authors have performed a systematic computational study of the hydrogen storage capacity model organometallic compounds consisting Sc, Ti, and V transition metal atoms bound to CmHm rings (m=4-6). For all complexes considered, is limited by 18-electron rule. maximum retrievable H2 uptake predicted 9.3 wt% using ScC4H4, slightly better than 9.1 TiC4H4, much larger approximately 7 with VC4H4, where only four molecules can be adsorbed. kinetic stability these hydrogen-covered reviewed in...

Motional heating of ions in microfabricated traps is one the open challenges hindering experimental realizations large-scale quantum processing devices. Recently, a series measurements rates surface-electrode ion characterized their frequency, distance, and temperature dependencies, but our understanding microscopic origin this noise remains incomplete. In work we develop theoretical model for electric field which associated with random distribution adsorbed atoms on trap electrode surface....

The elastic properties and mechanical stability of zirconium alloys hydrides have been investigated within the framework density functional perturbation theory. Results show that lowest-energy cubic Pn3[combining macron]m polymorph δ-ZrH1.5 does not satisfy all Born requirements for stability, unlike its nearly degenerate tetragonal P42/mcm polymorph. Elastic moduli predicted with Voigt-Reuss-Hill approximations suggest α-Zr, Zr-alloy Zr-hydride polycrystalline aggregates is limited by shear...

We review the recent progress achieved in theoretical description of chemical reactions at low temperatures. In particular, we discuss crucial role played by van der Waals interaction potential quantum-mechanical scattering calculations atom–diatom collisions cold and ultracold regimes, where abstraction proceed tunnelling. The importance zero-energy resonances enhancing reactivity zero-temperature limit is assessed. impact Feshbach associated with decay metastable states complexes on...

Among the numerous constituents of eukaryotic cells, DNA macromolecule is considered as most important critical target for radiation-induced damages. However, up to now ion-induced collisions on components remain scarcely approached and theoretical support still lacking describing main ionizing processes. In this context, we here report a description proton-induced ionization RNA bases well sugar–phosphate backbone. Two different quantum-mechanical models are proposed: first one based...

The structures of the only known minerals containing peroxide, namely studtite [(UO2)O2(H2O)4] and metastudtite [(UO2)O2(H2O)2], have been investigated using density functional theory. structure crystallizing in orthorhombic space group Pnma (Z = 4) is reported for first time at atomic level computed lattice parameters, a 8.45, b 8.72, c 6.75 Å, demonstrate that unit cell larger than previously dimensions 2) derived from experimental X-ray powder diffraction data.

A recently developed molecular three-continuum approximation is employed to compute differential cross sections for the ionization of hydrogen molecules by electron impact. Within framework this approximation, chosen final electronic wavefunction takes into account character target as well correlate motion between aggregates in channel reaction. Fivefold-differential a function both momenta state and orientation are studied different kinematical arrangements. Interference structures coming...

Thermal energy storage in salt hydrate phase change materials, such as magnesium chloride hydrates, represents an attractive option for solar applications. In this study, the structural, electronic, and thermodynamic properties of dichloride hexahydrate, MgCl2·6H2O, its dehydrated phases, MgCl2·nH2O (n = 4, 2, 1), were computed within framework density functional theory. Densities states predicted, phonon analysis using perturbation theory was performed at equilibrium volume to derive...

Fast highly charged C and O ion-induced total ionization of an RNA base molecule, uracil (C${}_{4}$H${}_{4}$N${}_{2}$O${}_{2}$, $m=112$ amu), has been investigated in a wide energy range keV to MeV. A combined study the collision products using time-of-flight mass spectrometer electron allows one determine absolute cross sections (TCSs). Experimental measurements TCSs are compared theoretical predictions performed classical trajectory Monte Carlo over-barrier (CTMC-COB) quantum mechanical...

The mechanical properties and stability of studtite, (UO₂)(O₂)(H₂O)₂·2H₂O, metastudtite, (UO₂)(O₂)(H₂O)₂, were investigated using density functional perturbation theory.

The structural, mechanical and thermodynamic properties of 1 : layered dioctahedral kaolinite clay, Al₂Si₂O₅(OH)₄, were investigated using density functional theory corrected for dispersion interactions. Good agreement is obtained with the recent experimental values reported well-crystallized samples.

We investigate the (0001) surface of single crystal quartz with a submonolayer Rb adsorbates. Using Rydberg atom electromagnetically induced transparency, we electric fields resulting from adsorbed on surface, and measure activation energy show that induces negative electron affinity (NEA) surface. The NEA allows low electrons to bind cancel field Our results will be important for integrating atoms into hybrid quantum systems, as fundamental probes atom-surface interactions, studies 2D gases...

A molecular three-continuum-type approximation is developed to study the $(e,2e)$ reaction for ${\mathrm{H}}_{2}$ targets. The nature of target treated within framework a two-effective-center approximation. correlate motion particles in final channel taken into account by an adequate product Coulomb functions. Triple differential cross sections are computed. good agreement with available experiments obtained.

The sequential growth of small titanium clusters with up to 15 atoms and the dissociative chemisorption H2 on minimum energy have been studied within density functional theory under generalized gradient approximation. It has found that low-energy grow three dimensionally from Ti4 follow a pentagonal pattern. Ti7 Ti13 show higher stability than other configuration bipyramid icosahedron structures, respectively. second difference binding plot indicates these two are highly stable; this agrees...

We combine experimental observations with ab initio calculations to study the reversible hydrogenation of single-wall carbon nanotubes using high boiling polyamines as reagents. Our characterize nature adsorption bond and identify preferential geometries at different coverages. find barrier for sigmatropic rearrangement chemisorbed hydrogen atoms be approximately 1 eV, thus facilitating surface diffusion formation energetically favored, axially aligned adsorbate chains. Chemisorbed modifies...

We use ab initio density functional calculations to study the microscopic mechanism underlying recently demonstrated hydrogenation of ${\text{C}}_{60}$ fullerene by diethylenetriamine reagent. Our results indicate that optimal monoaddition reaction is exothermic, involving an $\ensuremath{\approx}0.5\text{ }\text{eV}$ high activation barrier associated with simultaneous docking polyamine group and H transfer ${\text{C}}_{60}$. calculated vibrational frequencies can be used experimentally...

In this work, we report total cross sections for the single electron capture process induced on DNA/RNA bases by high-energy protons. The calculations are performed within both continuum distorted wave and wave-eikonal initial state approximations. biological targets described framework of self-consistent methods based complete neglect differential overlap model whose accuracy has first been checked simpler bio-molecules such as water vapour. Furthermore, multi-electronic problem...

The structure of dehydrated schoepite, α-UO2(OH)2, was investigated using computational approaches that go beyond standard density functional theory and include van der Waals dispersion corrections (DFT-D). Thermal properties were also obtained from phonon frequencies calculated with perturbation (DFPT) including corrections. While the isobaric heat capacity computed first-principles reproduces available calorimetric data to within 5% up 500 K, some entropy estimates based on measurements...

The interplay between thermodynamics and mechanical properties in the transformation of studtite, (UO2)(O2)(H2O)2·2H2O, into metastudtite, (UO2)(O2)(H2O)2, two important corrosion phases observed on surface uranium dioxide exposed to water, is revealed using density functional perturbation theory. Phonon calculations within quasi-harmonic approximation predict that standard entropy change for (UO2)(O2)(H2O)2·2H2O → (UO2)(O2)(H2O)2 + 2H2O reaction ΔS0 = +80 J·mol–1·K–1 production water liquid...

Transformer cores exhibiting higher operating power and improved efficiency are of great interest to electrical utilities, industry, the de-carbonization effort. Minnealloy, α″-Fe16(C,N)2, a martensite made only iron, nitrogen, carbon, has shown largest saturation magnetization any soft ferromagnet, 250 emu/g, tunable magnetocrystalline anisotropy. Given this represents significant increase in transferred per cycle compared legacy transformer core materials, we investigate three novel,...

A new, complete, theoretical rotational and vibrational line list for the A2Π ← X2Σ+ electronic transition in MgH is presented. The includes energies oscillator strengths all possible allowed transitions was computed using best available potential dipole moment function with former adjusted to account experimental data. X as well new lists B' 2Σ+ (pure rovibrational) were included comprehensive stellar atmosphere models M, L, T dwarfs solar-type stars. resulting spectra, when compared...