In this work the complete valence-band structure of molybdenum dichalcogenides ${\mathrm{MoS}}_{2},$ ${\mathrm{MoSe}}_{2},$ and $\ensuremath{\alpha}\ensuremath{-}{\mathrm{MoTe}}_{2}$ is presented discussed in comparison. The valence bands have been studied using both angle-resolved photoelectron spectroscopy (ARPES) with synchrotron radiation, as well ab initio band-structure calculations. ARPES measurements carried out constant-final-state (CFS) mode. results calculations show general very...

Abstract A novel method to calculate transition pathways between two known protein conformations is presented. It based on a molecular dynamics simulation starting from one conformational state as initial structure and using the other for directing constraint. The exemplified with T ↔ R of insulin. most striking difference these states that in 8 N-terminal residues B chain are arranged an extended strand whereas they forming helix. Both were simulated. proves capable finding continuous...

Almost all experiments and future applications of transition metal dichalcogenide monolayers rely on a substrate for mechanical stability, which can significantly modify the optical spectra monolayer. Doping from might lead to domination by trions. Here we show ab initio many-body theory that negative trion (A-) splits into three excitations, with both inter- intra-valley character, while positive counterpart (A+) consists only one inter-valley excitation. Furthermore, enhances screening,...

We report state-of-the-art first-principles calculations of the quasiparticle energies prototype homopolar and heteropolar covalent semiconductors described in terms electron self-energy operator. The wave functions are calculated within density-functional theory using local-density approximation employing nonlocal, norm-conserving pseudopotentials. operator is evaluated GW approximation. Employing plasmon-pole for frequency dependence dielectric matrix...

Ab initio calculations of structural and electronic properties the C(001)-(2 \ifmmode\times\else\texttimes\fi{} 1) diamond surface are reported discussed in direct comparison with Si(001) Ge(001). Our results strongly favor a symmetric dimer reconstruction as opposed to an asymmetric Si Ge (001). The physical origin quantitative nature reconstructions investigated systematically, it is shown by analyzing chemical trends why most subtle case for unequivocal structure determination.

We report ab initio calculations of the lattice constants and electronic band structure hexagonal wurtzite-structure semiconductors ZnO ZnS. employ local-density approximation solve Kohn-Sham equations for nonlocal, separable, norm-conserving pseudopotentials self-consistently. use basis sets localized Gaussian orbitals with s, p, d, ${\mathit{s}}^{\mathrm{*}}$ symmetry. In particular, we investigate influence Zn 3d electrons on results structure. Results employing both ${\mathrm{Zn}}^{2+}$...

We report the construction of pseudopotentials that incorporate self-interaction corrections and electronic relaxation in an approximate but very efficient, physically well-founded, mathematically well-defined way. These potentials are particularly useful for II-VI compounds which distinguished by their highly localized strongly bound cationic semicore d electrons. Self-interaction to local-density approximation (LDA) density-functional theory accounted solids a significant degree...

We report an efficient scheme for evaluating the quasiparticle corrections to local-density-approximation (LDA) band structures within GW approximation. In this scheme, self-energy are evaluated in a sufficiently flexible Gaussian orbital basis set instead of using plane-wave Fourier representations relevant two-point functions. It turns out that has include orbitals up f-type symmetry, when LDA calculations d-type symmetry needed convergence. For bulk Si, both schemes yield virtually...

We present the results of a comparative ab initio study single-walled SiC, BN, and BeO nanotubes (NTs) in zigzag armchair configurations. Within density functional theory, we employ self-interaction-corrected pseudopotentials that were shown previously to yield reliable for both structural electronic properties related bulk crystals. Using these pseudopotentials, investigate dependence atomic relaxation, strain energy, Young's modulus, structure on nanotube diameter compound ionicity....

We perform first-principles density-functional calculations to investigate the electronic and atomic structure formation energies of native defects selected impurities (O, Si, Mg) in InN. For p-type material, nitrogen vacancy has lowest energy. In n-type material all defect are high. discuss effect band-gap underestimate density functional theory (DFT), compare obtained using DFT (in local-density approximation, LDA) with a recently developed self-interaction relaxation-corrected (SIRC)...

Optimal adsorption geometries and respective surface band structures for monolayers of group-IV to group-VII adatoms on semi-infinite Si(001) substrates have been calculated from first principles using a self-consistent total-energy scheme. The calculations are based the local-density approximation employ nonlocal, norm-conserving pseudopotentials together with Gaussian orbital basis sets. geometry substrate is properly taken into account by employing our scattering theoretical method...

Atomically thin materials such as graphene or MoS2 are of high in-plane symmetry. Crystals with reduced symmetry hold the promise for novel optoelectronic devices based on their anisotropy in current flow light polarization. Here, we present polarization-resolved optical transmission and photoluminescence spectroscopy excitons 1T'-ReSe2. On reducing crystal thickness from bulk to a monolayer, observe strong blue shift band gap 1.37 1.50 eV. The strongly polarized dipole vectors along...

We introduce a scanning probe technique that enables three-dimensional imaging of local electrostatic potential fields with subnanometer resolution. Registering single electron charging events molecular quantum dot attached to the tip an atomic force microscope operated at 5 K, equipped qPlus tuning fork, we image quadrupole field molecule. To demonstrate quantitative measurements, investigate dipole metal adatom adsorbed on surface. show because its high sensitivity can potentials large...

The effect of a magnetic field on the optical absorption in semiconductors has been measured experimentally and modeled theoretically for various systems previous decades. We present new first-principles approach to systematically determine response excitons fields, i.e. exciton $g$ factors. By utilizing $GW$-Bethe-Salpeter equation methodology we show that factors extracted from Zeeman shift electronic bands are strongly renormalized by many-body effects which trace back extent reciprocal...

We report results of an efficient approach for performing self-consistent ab initio calculations structural and electronic properties II-VI semiconductors which overcomes to a large extent well-known shortcomings the local-density approximation (LDA) these d-band compounds. Dominant atomic self-interaction corrections are taken into account by employing appropriately constructed pseudopotentials in framework standard LDA calculations. Our ZnO, ZnS, CdS, CdSe excellent agreement with whole...

We present first-principles calculations of structural and electronic properties group-III nitrides in wurtzite zinc-blende structure. For a most accurate treatment these wide-band-gap semiconductors within local density approximation we employ our self-interaction- relaxation-corrected pseudopotentials together with Gaussian-orbital basis sets. The results for BN, AlN, GaN, InN are good agreement host experimental data yielding consistent theoretical description this class technologically...

Quasiparticle band structure calculations which include the most important cationic core states in $\mathrm{GW}$ approximation of self-energy operator are reported for a prototype II-VI semiconductor. The salient feature our results cubic CdS is finding that complete $N$ shell needs to be included pseudopotential and order obtain reasonable agreement with experiment.

We report ab initio calculations of the surface electronic structure hexagonal wurtzite semiconductors ZnO and CdS. The are carried out self-consistently in local-density approximation employing separable norm-conserving pseudopotentials. Localized Gaussian orbitals used basis set for an efficient description strongly localized wave functions. Zn 3d Cd 4d electrons explicitly taken into account as valence since they important a quantitative structural well properties, our investigations bulk...

The electronic structure of semi-infinite semiconductors with energy-optimized reconstructed surfaces is calculated self-consistently for the first time. Using local-density-functional formalism and scattering theory, calculations yield potential, charge density, surface band structure, wave-vector-resolved layer densities states extreme spectral resolution. results quantitatively explain recent spectroscopy data on occupied empty Ge(001) (2\ifmmode\times\else\texttimes\fi{}1) Si(001)...

Employing the $GW$ method, we discuss electronic and topological properties of ${\mathrm{Bi}}_{2}{\mathrm{Te}}_{3}$ ${\mathrm{Sb}}_{2}{\mathrm{Te}}_{3}$ thin films consisting one to six quintuple layers (QLs). Although both bulk materials are three-dimensional insulators, two-dimensional phases their differ. We find nontrivial quantum spin Hall phase, together with a sizable band gap 0.13 eV, for film 2 QL thickness, whereas hosts topologically trivial structure. All our results in excellent...

We present quasiparticle band structures for the clean, reconstructed Ge(001)-(2\ifmmode\times\else\texttimes\fi{}1), as well hydrogen-terminated H:Ge(001)-(2\ifmmode\times\else\texttimes\fi{}1) and sulfur-terminated S:Ge(001)-(1\ifmmode\times\else\texttimes\fi{}1) surface. The electronic self-energy operator is evaluated within GW approximation which allows one to overcome well-known deficiencies of LDA band-structure calculations. find good agreement our results with a number...

We report ab initio calculations of structural and electronic properties hexagonal 6H-SiC(0001) surfaces. The have been carried out self-consistently within a local density approximation employing supercell geometries, smooth norm-conserving pseudopotentials in separable form Gaussian orbital basis sets. In systematic study, we investigated the relaxation, as well ($\sqrt{3}$\ifmmode\times\else\texttimes\fi{}$\sqrt{3}$)R30\ifmmode^\circ\else\textdegree\fi{} reconstructions both Si-...

We report a detailed experimental and theoretical investigation of the Fermi-surface topology layered transition-metal dichalcogenide $2H\ensuremath{-}{\mathrm{NbSe}}_{2},$ which undergoes second-order phase transition into an incommensurate two-dimensional charge-density-wave at 33.5 K. High-resolution angle-resolved photoemission with synchrotron radiation yields two Nb $4d$-related cylinders Se ${4p}_{z}$-derived pocket around center Brillouin zone, in good agreement results fully...