This paper summarises the theory and functionality behind Questaal, an open-source suite of codes for calculating electronic structure related properties materials from first principles. The formalism linearised muffin-tin orbital (LMTO) method is revisited in detail developed further by introduction short-ranged tight-binding basis functions full-potential calculations. LMTO presented both Green's function wave formulations bulk layered systems. suite's code uses a sophisticated...

We perform an ab initio study of the ordered phases IrMn and ${\text{IrMn}}_{3}$, most widely used industrial antiferromagnets. Calculation form strength magnetic anisotropy allows construction effective spin model, which is tested against experimental measurements regarding ground state N\'eel temperature. Our challenging result extremely strong second-order for ${\text{IrMn}}_{3}$ appearing in its frustrated triangular state, surprising since $L{1}_{2}$ phase has a cubic symmetry. explain...

Abstract Mn 3 Sn has recently attracted considerable attention as a magnetic Weyl semimetal exhibiting concomitant transport anomalies at room temperature. The topology of the electronic bands, their relation to ground state and nonzero Berry curvature lie heart problem. examination full Hamiltonian reveals otherwise hidden aspects these unusual physical properties. Here, we report spin wave spectra measured over wide momentum—energy range by inelastic neutron scattering technique. Using...

In order to derive tensorial exchange interactions and local magnetic anisotropies in itinerant systems, an approach combining the spin-cluster expansion with relativistic disordered moment scheme is introduced. The theoretical background computational aspects of method are described detail. site-resolved anisotropy contributions for IrMn${}_{3}$/Co(111) interface, a prototype bias system, calculated including large number sites from both antiferromagnet ferromagnet. Our calculations reveal...

The exchange bias effect in compensated IrMn3/Co(111) system is studied using multiscale modeling from "ab initio" to atomistic calculations. We evaluate numerically the out-of-plane hysteresis loops of bi-layer for different thickness ferromagnetic layer. results show existence a perpendicular field and an enhancement coercivity system. In order elucidate possible origin bias, we analyze selected by tuning contributions interactions across interface. Our indicate that primarily induced...

The thermal decomposition of diborane-phosphine mixtures in a hydrogen atmosphere and the reduction boron tribromide-phosphorus trichloride with have been used for deposition phosphide on basal plane hexagonal silicon carbide substrates. In process, substrate must be maintained at temperatures below 900°C to minimize contribution gas-phase reactions, layers showed only preferred orientations. process was carried out over wide temperature range, deposited face substrates 1050°–1150°C were...

The structure of weeksite, K 1.26Ba0.25Ca0.12((UO2)2(Si5O13))H2O, orthorhombic, a 14.209(2), b 14.248(2), c 35.869(4) A, V 7262(2) A 3 , space group Cmmb, has been solved by direct methods using data collected with Mo KX-radiation and CCD- based detector refined full-matrix least-squares techniques, on the basis F 2 for all unique reflections, to an agreement factor (R1) 7.0% goodness-of-fit ( S) 1.04, calculated 1565 observed reflections Fo ≤ 4� F). contains four U 6+ positions, each which...

The fusion temperature (Tφ), the oxygen partial pressure (PO2) during melting and quenching rate from Tφ all influence optical absorption in 5.06-eV (245-nm) region. These observations are consistent with assumption that defect responsible for is an vacancy or complex of vacancies. activation energy formation GeO2 glasses which repsonsible 2.3 eV larger than diffusion (∼1 eV).

The crystal growth of boron phosphide, BP, has been investigated using two approaches: (i) the addition phosphorus to a boron‐nickel or boron‐copper melt, and (ii) recrystallization phosphide from nickel copper solution in temperature gradient. To determine optimum conditions for processes, solubility subphosphide was determined over wide range. found be higher than that phosphide. Boron crystals about 3‐mm size were obtained by melt at 1300°C above, followed slow cooling. gradient 1200°C...

Antiferromagnets (AFMs) are strong candidates for the future spintronic and memory applications largely because of their inherently fast dynamics lack stray fields, with ${\mathrm{Mn}}_{2}\mathrm{Au}$ being one most promising. For numerical modeling magnetic material properties, it is common to use ab initio methods, atomistic models, micromagnetics. However, each method alone describes physics within certain limits. Multiscale methods bridging gap between these three approaches have been...

Yttrium iron garnet is a complex ferrimagnetic insulator with 20 magnon modes which used extensively in fundamental experimental studies of magnetisation dynamics.As transition metal oxide moderate gap (2.8 eV), yttrium requires careful treatment electronic correlation.We have applied quasiparticle self-consistent GW to provide fully ab initio description the structure and resulting magnetic properties, including parameterisation Heisenberg model for exchange interactions.Subsequent spin...

The site-specific behavior of iron in an orthoenstatite-structured 57Fe-enriched (M1)(M2)Si2O6 powdered sample was explored using synchrotron Mössbauer spectroscopy and diamond-anvil cells two independent experiments at ambient temperature. In one experiment, NaCl used as the pressure- transmitting medium (ambient pressure to 36 GPa), other Ne surrounded (4.1 26.8 GPa). hyperfine parameters M1 M2 sites room are excellent agreement with previous literature values obtained conventional yield...

${\mathrm{KCoO}}_{2}$ has been found in 1975 to exist a unique structure with $P4/nmm$ space group featuring Co atoms square pyramidal coordination. The the plane are linked by O arrangement reminiscent of cuprates. However, its electronic not studied until now. Unlike ${\mathrm{LiCoO}}_{2}$ and ${\mathrm{NaCoO}}_{2}$, which octahedral coordination nonmagnetic band insulators, unusual ${d}^{6}\phantom{\rule{4pt}{0ex}}{\mathrm{Co}}^{3+}$ is here shown lead magnetic stabilization an insulating...

The dc electrical properties of a series high purity GeO2 glasses fused and equilibrated at various temperatures (Tφ) in air were measured. Tφ ranged from 1200 to 1690 °C. observed changes are not correlated concentration any the impurities as determined by neutron activation analyses or IR measurements OH concentrations. resistivity was found obey an Arrhenius function with enthalpy approximately 1.0 eV for all Tφ’s except =1200 charge carrier concluded be Na+ ion. mobility ion calculated...

Among North American survivors of critical illness, we aim to describe the prevalence post-traumatic stress disorder (PTSD), and its subtypes intrusion, avoidance, hyperarousal.

Using first-principles calculations, based on disordered local moment theory, combined with the self-interaction corrected spin density approximation, we study magnetic interactions in GdX intermetallics for X = Cu, Zn, Ga, Cd, and Mg. Our predicted orders ordering temperatures both at zero other pressures agree well experiments including large increase Curie temperature of GdCd under pressure that is shown by our own experimental measurements. From results it emerges...

KCoO2 has been found in 1975 to exist a unique structure with P4/nmm spacegroup Co square pyramidal coordination the atoms plane linked by O arrangement reminiscent of cuprates but its electronic not studied until now. Unlike LiCoO2 and NaCoO2 octahedral coordination, which are non-magnetic band insulators, unusual d6 Co^{3+} is here shown lead magnetic stabilization an insulating high moments 4{\mu}B per Co. The calculated using quasiparticle self-consistent (QS)GW method basic formation...

Questaal is a set of codes developed for calculating the electronic structure materials from first principles. Developed by Mark van Schilfgaarde and his collaborators, descends work Ole K. Andersen group in Stuttgart during 80's on linear muffin-tin orbital (LMTO) method. This an atom-centred basis that construction particularly efficient solving band problem. As has evolved, variety techniques aimed at addressing both different material problems implementing levels theory have been...

Antiferromagnets (AFMs) are strong candidates for the future spintronic and memory applications largely because of their inherently fast dynamics lack stray fields, with Mn2Au being one most promising. For numerical modelling magnetic material properties, it is common to use ab-initio methods, atomistic models micromagnetics. However, each method alone describes physics within certain limits. Multiscale methods bridging gap between these three approaches have been already proposed...