Related papers: Ab initio wavefunction based methods for excited s…
We investigate the electronic structure of the transition-metal oxide YVO3 by a hybrid first-principles scheme. The density-functional theory with the local-density-approximation by using the local muffin-tin orbital basis is applied to…
We study the structural and electronic properties of phase III of solid hydrogen using accurate many-electron theories and compare to state-of-the-art experimental findings. The atomic structures of phase III modelled by C2/c-24 crystals…
We calculate correlation functions of exactly-solvable one-dimensional flat-band models by utilizing the "molecular-orbital" representation. The models considered in this paper have a gapped ground state with flat-band being fully occupied,…
Orbital degrees of freedom can have pronounced effects on the fundamental properties of electrons in solids. In addition to influencing bandwidths, gaps, correlation strength and dispersion, orbital effects have also been implicated in…
The band gap of alkali halides, alkaline-earth oxides, Al2O3 and SiO2 crystals has been calculated using the Perturbed-Ion model supplemented with some assumptions for the treatment of excited states. The gap is calculated in several ways:…
Recent work from our research group has demonstrated that symmetry-projected Hartree--Fock (HF) methods provide a compact representation of molecular ground state wavefunctions based on a superposition of non-orthogonal Slater determinants.…
Charge carrier concentrations in acceptor-doped proton-conducting perovskites are to a large extent determined by the hydration and oxidation of oxygen vacancies, which introduce protons and holes, respectively. First-principles modeling of…
We develop a simple model to compute the energy-dependent decay factors of metal-induced gap states in metal/insulator interfaces considering the collective behaviour of all the bulk complex bands in the gap of the insulator. The agreement…
Theoretical descriptions of the spectrum of electronic excitations in real metals have not yet reached a fully predictive, "first-principles" stage. In this paper we begin by presenting brief highlights of recent progress made in the…
The conductance of bulk metal--insulator--metal junctions is evaluated by the Landauer formula using an \textit{ab initio} electronic structure calculated using a plane-waves basis set within density-functional theory (DFT) and beyond,…
Hexagonal boron nitride ($\it h$-BN) exhibits dominant $\pi$-bands near the Fermi level, similar to graphene. However, unlike graphene, where tight-binding (TB) models accurately reproduce band edges near the $K$ and $K^{\prime}$ points in…
A non-iterative method is presented to calculate the closest Wannier functions (CWFs) to a given set of localized guiding functions, such as atomic orbitals, hybrid atomic orbitals, and molecular orbitals, based on minimization of a…
We report the calculated fundamental band gaps of \emph{wurtzite} ternary alloys Zn$_{1-x}$M$_x$O (M=Mg, Cd) and the band offsets of the ZnO/Zn$_{1-x}$M$_x$O heterojunctions, these II-VI materials are important for electronics and…
In this work an overall electronic structure including the position and formation energies of various intrinsic defects are computed for anatase using Density Functional Theory aided by Hubbard correction (DFT+U). The intrinsic point…
Electronic structure of the manganese oxide solid is studied by the quantum Monte Carlo (QMC) methods. The trial wavefunctions are built using orbitals from unrestricted Hartree-Fock and Density Functional Theory, and the electron-electron…
In this paper we present an approach aimed at performing many-body calculations of Born-effective charges of crystalline insulators, by including the electron-correlation effects. The scheme is implemented entirely in the real space, using…
We report on optical properties of various polymorphs of hafnia predicted within the framework of density functional theory. The full potential linearised augmented plane wave method was employed together with the Tran-Blaha modified…
Magic angle twisted bilayer graphene (MATBG) hosts narrow moir\'e bands with meV-scale energy splittings, making its correlated phases sensitive to both material parameters and modeling choices in low-energy downfolding. We develop an ab…
UV emitters based on the semiconductor alloy aluminium gallium nitride, (Al,Ga)N, have attracted significant interest in recent years due to their potential for optoelectronic devices. To guide the design of such devices with improved…
We compute the electronic band structure and optical properties of boron arsenide using the relativistic quasiparticle self-consistent $GW$ approach, including electron-hole interactions through solution of the Bethe-Salpeter equation. We…