Related papers: Helium under high pressure: A comparative study of…
Density functional theory (DFT) can run into serious difficulties with localized states in elements such as transition metals with occupied-d states and oxygen. In contrast, Hartree-Fock (HF) method can be a better approach for such…
The electronic structures of rare-earth elements in the HCP structure, and Europium in the BCC structure, are calculated by use of density-functional theory, DFT. Simulation of X-ray photoemission spectroscopy (XPS) and bremsstrahlung…
Recent experimental results on two hcp phases of barium under high pressure show interesting variation of the lattice parameters. They are here interpreted in terms of electronic structure calculation by using the LMTO method and…
We have calculated the electronic structure of Eu for the bcc, hcp, and fcc crystal structures for volumes near equilibrium up to a calculated 90 GPa pressure using the augmented-plane wave method in the local-density approximation. The…
Hybrid density functionals, which replaces a fraction of density functional theory (DFT) exchange with exact Hartree-Fock (HF) exchange, have been used to study the structural, magnetic, and electronic properties of delta-Plutonium. The…
The equation of state, structural behavior and phase stability of {\alpha}-uranium have been investigated up to 1.3 TPa using density functional theory, adopting a simple description of electronic structure that neglects the spin-orbit…
To understand the pressure-induced changes in the electronic structure and the electron-phonon interaction in yttrium, we have studied hexagonal close-packed (hcp) yttrium, stable at ambient pressure and double hexagonal close-packed (dhcp)…
The electronic structures of element cerium under high pressure remain unclear all the time. We tried to calculate the electronic structures of $\alpha'$, $\alpha"$, and $\epsilon$-Ce which only exist in the presence of pressure, by using…
Lithium - the lightest alkali metal - exhibits unexpected structures and electronic behaviour at high pressures. As the heavier alkalis, Li is bcc at ambient pressure and transforms first to fcc (at 7.5 GPa). The post-fcc high-pressure form…
We compare the behavior of the finite-temperature Hartree-Fock model with that of thermal density functional theory using both ground-state and temperature-dependent approximate exchange functionals. The test system is bcc Li in the…
Density Functional Theory (DFT) calculations show a weak interaction between hydrogen and helium in iron, in contrast to previous reports of a strong trapping of hydrogen at helium. The strong preference of He and H to occupy regions with…
Density-functional calculations are presented for high-pressure structural phases of S and Se. The structural phase diagrams, phonon spectra, electron-phonon coupling, and superconducting properties of the isovalent elements are compared.…
We scrutinize the accuracy of the pseudopotential approximation in density-functional theory (DFT) calculations of surfaces by systematically comparing to results obtained within a full-potential setup. As model system we choose the CO…
We discuss the role of dynamical many-electron effects in the physics of iron and iron-rich solid alloys under applied pressure on the basis of recent ab initio studies employing the dynamical mean-field theory (DMFT). Electronic…
Helium (He) is the most inert noble gas at ambient conditions. It adopts a hexagonal close packed structure (P63/mmc) and remains in the insulating phase up to 32 TPa. In contrast, lithium (Li) is one of the most reactive metals at zero…
Density functional theory (DFT) is a widespread and effective tool in electronic structure calculations for ground-state electron systems. Its success has prompted exploration into the use of DFT for non-collective excited states. The delta…
We present in full detail a newly developed formalism enabling density functional perturbation theory (DFPT) calculations from a DFT+$U$ ground state. The implementation includes ultrasoft pseudopotentials and is valid for both insulating…
Understanding the properties of molecular solids at high pressure is a key element in the development of new solid-state theories. However, the most commonly used generalized-gradient approximation (GGA) of the density functional theory…
Evolutionary searches were employed to predict the most stable structures of perovskites with helium atoms on their A-sites up to pressures of 10 GPa. The thermodynamics associated with helium intercalation into [CaZr]F6, structure that…
Internal energies, enthalpies, phonon dispersion curves, and superconductivity of atomic metallic hydrogen are calculated. The (standard) use pseudopotentials in density-functional theory are compared with full (Coulomb)-potential…