Our density functional theory study of hydroperoxy (OOH) intermediates on various model titanosilicalite (TS-1) Ti centers explores how microstructural aspects of Ti sites effect propylene epoxidation reactivity and shows that Ti sites located adjacent to Si vacancies in the TS-1 lattice are more reactive than fully coordinated Ti sites, which we find do not react at all. We show that propylene...

The energetic properties of ternary Zr–Nb–Sn Zirconium-based alloy with concentration dissolved alloying elements ∼ 1 . 5 % are studied by using density functional theory. possibility additions separated different distances to dissolve/segregate in a host matrix is analyzed the help mixing energy and solute–solute binding energy. ability solutes trap single vacancy discussed studying formation ...

We perform first-principles density-functional theory calculations to investigate the structural and electronic properties and the formation energies of nitrogen vacancies in wurtzite InN. We report an extensive and systematic study of the favorable atomic and electronic configurations of up to six vacancies in large supercells. The isolated vacancy acts as a donor in a p-type material where th...

Using density functional theory (DFT) calculations, we investigated oxygen vacancy diffusion and aggregation in relation to dielectric breakdown in amorphous silicon dioxide (a-SiO2). Our calculations indicate the existence of favourable sites for the formation of vacancy dimers and trimers in the amorphous network with maximum binding energies of approximately 0.13 eV and 0.18 eV, respectively...

Based on the density functional theory (DFT), the electronic properties of O-doped pure and sulfur vacancy-defect monolayer WS₂ are investigated by using the first-principles method. For the O-doped pure monolayer WS₂, four sizes (2 × 2 × 1, 3 × 3 × 1, 4 × 4 × 1 and 5 × 5 × 1) of supercell are discussed to probe the effects of O doping concentration on the electronic structure. For the 2 × 2 × ...

We present an in-depth analysis of the atomic and electronic structure of the quasi-one-dimensional 1D surface reconstruction of Ga on Si 112 based on scanning tunneling microscopy and spectroscopy STM and STS , Rutherford-backscattering spectrometry RBS , and density functional theory DFT calculations. A new structural model of the Si 112 6 1-Ga surface is inferred. It consists of Ga zigzag ch...

The electronic behavior of metallic carbon nanotubes under the influence of atomistic vacancy defects present in the channel is theoretically investigated using non-equilibrium Green’s function method self-consistently coupled with three-dimensional electrostatics. A nearest neighbor tight binding model based on a single pz orbital is used for the device Hamiltonian. A single vacancy defect in ...

We find, using a local density approximation +Hubbard U method, that oxygen vacancies tend to cluster in a linear way in SrTiO(3), a prototypical perovskite oxide, accompanied by strong electron localization at the 3d state of the nearby Ti transition metal ion. The vacancy clustering and the associated electron localization lead to a profound impact on materials properties, e.g., the reduction...

Using first principles based on density functional theory (DFT), the CO, NH3, NO, and NO2 gas adsorbed intrinsic Graphite-like ZnO (g−ZnO) vacancy-deficient g−ZnO were systematically studied. For g−ZnO, adsorption energy of defective systems increased significantly due to introduction Zn vacancy (VZn). Especially, for Zn-vacancy (VZn/g−ZnO) 1.366 eV, 2.540 eV 2.532 respectively. In addition, wi...