A5038840462- Advanced Chemical Physics Studies
- Rare-earth and actinide compounds
- Magnetic and transport properties of perovskites and related materials
- Physics of Superconductivity and Magnetism
- Boron and Carbon Nanomaterials Research
- High-pressure geophysics and materials
- Advanced Condensed Matter Physics
- Heusler alloys: electronic and magnetic properties
- Metal and Thin Film Mechanics
- Magnetic Properties of Alloys
- Inorganic Chemistry and Materials
- Magnetic properties of thin films
- Spectroscopy and Quantum Chemical Studies
- X-ray Diffraction in Crystallography
- Semiconductor materials and devices
- Surface and Thin Film Phenomena
- Electronic and Structural Properties of Oxides
- Solid-state spectroscopy and crystallography
- Inorganic Fluorides and Related Compounds
- Intermetallics and Advanced Alloy Properties
- Semiconductor materials and interfaces
- Iron-based superconductors research
- Electron and X-Ray Spectroscopy Techniques
- Graphene research and applications
- Superconductivity in MgB2 and Alloys
TU Wien
2012-2021
Agency for Science, Technology and Research
2020
Northwestern University
2020
Institute of High Performance Computing
2020
Institut des Matériaux Jean Rouxel
2011
Nantes Université
2011
University of Graz
1994-2010
University of Salzburg
2010
John Wiley & Sons (United States)
1979-2009
University of Vienna
1994-2008
The WIEN2k program is based on the augmented plane wave plus local orbitals (APW+lo) method to solve Kohn-Sham equations of density functional theory. APW+lo method, which considers all electrons (core and valence) self-consistently in a full-potential treatment, implemented very efficiently WIEN2k, since various types parallelization are available many optimized numerical libraries can be used. Many properties calculated, ranging from basic ones, such as electronic band structure or atomic...
A comparison of DFT methods Density functional theory (DFT) is now routinely used for simulating material properties. Many software packages are available, which makes it challenging to know the best use a specific calculation. Lejaeghere et al. compared calculated values equation states 71 elemental crystals from 15 different widely codes employing 40 potentials (see Perspective by Skylaris). Although there were variations in values, most recent and converged toward single value, with...
We have examined two criteria for determining the exchange parameter $\ensuremath{\alpha}$ which occurs in $X\ensuremath{\alpha}$ local-statistical-exchange approximation, an approximation widely used energy-band and molecular calculations. These are (i) adjustment of statistical total energy to Hartree-Fock energy, leading ${\ensuremath{\alpha}}_{\mathrm{HF}}$, (ii) satisfaction virial theorem, ${\ensuremath{\alpha}}_{\mathrm{vt}}$. calculated values corresponding these neutral atoms H...
We present a detailed analysis of the $\mathrm{APW}+\mathrm{lo}$ basis set for band-structure calculations. This consists energy independent augmented plane-wave (APW) functions. The linearization is introduced through local orbitals evaluated at same as APW It shown that results obtained with converge much faster and often more systematically towards final value. thereby allows accurate treatment systems were previously unaccessible to linearized APW. Furthermore, it converges total LAPW...
The thermal properties of the 14 nonmagnetic cubic metals through 4d transition series are derived from first-principles electronic-structure calculations coupled with a Debye treatment vibrating lattice. temperatures and Gr\"uneisen constants an analysis compressional characteristics rigid-lattice binding curves used to define contribution lattice vibrations free energy. A minimization resulting energy respect volume yields temperature-dependent separations coefficients expansion....
The band structure of chromium dioxide, which is an important material because its magnetic properties, has been calculated with the augmented spherical wave method by performing self-consistent spin-polarised calculations. majority-spin electrons are metallic, whereas minority-spin semiconducting. A new class half-metallic ferromagnets found in rutile structure.
The different magnetic phases of the bcc and fcc forms Fe, Co, Ni are studied by analyzing total-energy surfaces in moment-volume parameter space obtained from energy-band calculations using a local-spin-density approximation. surfaces, found calculating total energies while holding both moment volume fixed, offer method for studying that inaccessible to traditional self-consistent-field methods. We find moments can change discontinuously with there ranges coexistence phases. In multiphase...
The II-VI semiconductors ZnO and ZnSe have been investigated by x-ray $^{67}\mathrm{ssbauer}$ spectroscopy at high external pressures. In ZnSe, the recoilfree fraction f increases from f=0.50% ambient pressure to 1.19% 6.1 GPa. It then decreases f=0.92% as is further raised 8.2 This decrease of caused softening phonon modes which occurs far below crystallographic phase transition (13.5 GPa). high-pressure (NaCl structure), low-frequency acoustic-phonon become harder high-frequency optic...
By using the augmented-plane-wave method in connection with X alpha for exchange, self-consistent band structures eight compounds have been calculated. means of wavefunctions, a charge analysis is presented. The Slater-Koster LCAO interpolation scheme applied to yield accurate densities states and partial states.
Recently, Engel and Vosko have proposed an alternative form of a generalized gradient approximation (GGA) [Phys. Rev. B 47, 13 164 (1993)] within density-functional theory. This version the GGA (EV93) was obtained by optimizing exchange-correlation potential ${\mathit{V}}_{\mathrm{xc}}$ instead corresponding energy ${\mathit{E}}_{\mathrm{xc}}$. We applied this functional to various solids found that equilibrium lattice constants generally are far too large in comparison experiment, so...
For the treatment of strongly correlated electrons, corresponding Hartree-Fock exchange energy is used instead local density approximation (LDA) or generalized gradient (GGA) functional, as suggested recently [P. Nov\'ak et al., Phys. Status Solidi B 243, 563 (2006)]. If this done only inside atomic spheres, using an augmented plane wave scheme, a significant simplification and reduction computational cost achieved with respect to usual but costly implementation formalism in solids. Starting...
We present the results of Kohn-Sham calculations on molecules, surfaces, and solids which were obtained using a recently proposed exchange-correlation energy functional [Z. Wu R. E. Cohen, Phys. Rev. B 73, 235116 (2006)]. The Wu-Cohen (WC) functional, like well-known PBE [J. P. Perdew et al., Lett. 77, 3865 (1996)], is generalized gradient approximation form was derived from homogeneous electron gas mathematical relations obeyed by exact functional. molecular systems show that among...
Recently, a simple analytical form for the exchange potential was proposed by Becke and Johnson. This potential, which depends on kinetic-energy density, shown to reproduce very well shape of exact (obtained with optimized effective method) atoms. Calculations solids show that Becke–Johnson leads better description band gaps semiconductors insulators respect standard local density Perdew–Burke–Ernzerhof approximations exchange–correlation potential. Comparison is also made values obtained...
The cubic Laves phase of YCo2 is near a transition from paramagnetic to magnetically ordered state. Self-consistent energy-band calculations yield the total energy and magnetic moment as functions volume. new fixed spin-moment (FSM) method, which allows one calculate an explicit function magnetisation, introduced. At theoretical equilibrium volume found be strongly enhanced Pauli paramagnet, but at slightly larger lattice constant metamagnetic seems possible. Its occurrence can understood on...
The electric field gradient can be obtained from self-consistent energy-band calculations by the linearized-augmented-plane-wave method provided that a general potential is used. This first-principles method, which does not rely on any Sternheimer antishielding factor, tested for ${\mathrm{Li}}_{3}$N and yields gradients Li(1), Li(2), N in excellent agreement with NMR experiments. mainly determined local distortions of electronic charge density, especially case polarizable...
The electric-field gradient (EFG) for all hcp metals from Be to Cd is obtained energy-band calculations using the full-potential linearized-augmented-plane-wave (LAPW) method. Our first-principles method, which does not rely on any Sternheimer antishielding factor, yields EFG's in good agreement with experiment and predicts also sign of EFG's. EFG was found be determined mainly by nonspherical distribution valence-electron density close nucleus. In general, contributions originating p states...
The thermoelectric properties of filled gallium-germanium clathrates are analyzed from a band-structure point view. Using the virtual crystal approximation undoped calculated to be semiconductors with band gaps around 0.6--0.9 eV. conduction bands hybridize unoccupied d states guest atoms. This means that n-doped type-I depend strongly on atom while p doped relatively unaffected. type-VIII structures have disperse centered voids in framework structure. explains low effective masses observed...
The electric-field gradients (EFG's) of ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{7}$, ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6.5}$, and ${\mathrm{YBa}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{6}$ are calculated on a first-principles basis using the full-potential linear augmented-plane-wave (LAPW) method in which exchange correlation effects treated by local-density approximation (LDA). Good agreement with experimental EFG's their anisotropies is found for Cu(1)...