The interlayer binding energy of graphite is obtained by a semiempirical method in which ab initio calculations based on the density functional theory (DFT) are supplemented with an empirical van der Waals (vdW) interaction. local approximation (LDA) and generalized gradient (GGA) used DFT calculations, damping (or interpolation) function to combine these results vdW interaction fitted observed spacing $c$-axis elastic constant. energies calculated LDA GGA quite different, but combined...

Irradiation-induced vacancy-type defects in Fe-based dilute binary alloys (Fe-C, Fe-Si, Fe-P, Fe-Mn, Fe-Ni, and Fe-Cu), model of nuclear reactor pressure vessel steels, are studied by positron annihilation methods, lifetime, coincidence Doppler broadening (CDB) radiation. The were induced 3 MeV electron irradiation at room temperature. defect concentrations much higher than that pure Fe irradiated the same condition, indicating strong interactions between vacancies solute atoms formation...

We apply the density-functional theory to study energetics of lithium ion adsorption on single-wall carbon nanotubes (SWNTs). use both local-density approximation (LDA) and generalized-gradient (GGA) for exchange-correlation energy functional. Both LDA GGA calculations indicate that processes onto pristine defective (8,0) SWNT are exothermic with respect metallic lithium. On other hand, (5,5) can be endothermic depending defect structures. As ring surface becomes large, barrier diffusion...

Pressure and compressibility of simple metals such as alkali metals, Zn, Al Pb are calculated in the liquid state near triple point, using pseudopotential formalism for electron-ion interaction. Effective ion-ion interaction is defined naturally by calculating total energy to second order its contributions pressure bulk modulus separately use so-called equation modified properly include effects density-dependence (due electronic screening effect) effective potential. It found that these much...

A new general formulation for calculating the wave-number dependence of plasmon damping in metals, including effects both electron-electron and electron-ion interactions, is presented. As an important application formalism, case electron gas investigated. The detailed calculation probabilities decay by producing two electron-hole pairs made. exchange processes are also numerical result q 2 coefficient rate considerably smaller than that obtained previous theories. process via excitation one...

Energy spectra of positron annihilation radiation were measured in polymer blends polyethylene and ethylene vinyl acetate copolymer (E/VA) by means the coincidence Doppler broadening technique. Positron with core electrons oxygen was appreciably increased addition small amounts E/VA to detected a sensitivity one order magnitude higher than would be expected from number density atoms blends. This clearly shows that is sensitively trapped polar group demonstrates usefulness positrons as...

In this paper we have developed a theory of energetics for isolated single-wall carbon nanotubes (SWNTs) deformed in the radial direction, and applied to investigate their deformation characteristics stability under hydrostatic pressure. The starting point is strain energy SWNTs predicted by ab initio calculations based on density functional (DFT), which shows same behavior as that obtained continuum elastic shell model. We extend result inflated with circular cross section calculate SWNT...

Nanostructural evolution of Cr (Cr-rich) precipitates in a Cu-0.78%Cr-0.13%Zr alloy has been studied after aging and overaging (reaging) by laser assisted local electrode 3 dimensional atom probe (Laser-LEAP). This material is candidate for the first wall divertor components future fusion reactors. After prime at 460°C, enriched with Zr were observed. Further reaging 600°C caused to grow almost spherical 5 nm (1 h) diameter plate-like ones 20 (4 h), respectively. impurities Si Fe...

We have developed a semiempirical method to obtain interlayer binding energy of graphite in the previous work [M. Hasegawa and K. Nishidate, Phys. Rev. B 70, 205431 (2004)]. In present paper, we revisit this approach develop an improved method, which ab initio calculations based on density functional theory (DFT) are also corrected through empirical atom-atom van der Waals (vdW) interaction. The local approximation (LDA) generalized gradient (GGA) used DFT calculations. parametrized damping...

Three dimensional dopant distributions in polycrystalline Si gate of n-type (n-) and p-type (p-) metal-oxide-semiconductor field effect transistor (MOSFET) structure were investigated by laser-assisted three atom probe. The remarkable difference distribution between n-MOSFET p-MOSFET was clearly observed. In gate, As P atoms segregated at grain boundaries the interface oxide. No diffusion into oxide On other hand, p-MOSFET, no segregations B or observed, directly

We performed density-functional electronic structure calculations for wurtzite CdS with native defects and Cu impurity. investigate formation energies ionization levels of the in various charge states. Our results reveal that S vacancy is a double donor strongly localized orbital at defect site, could act as an intrinsic compensation under $p$-type doping. On other hand, interstitial tetrahedral site acceptor which forms into dumbbell-like atomic configuration nearest atom. The impurity...

Assuming that the electron-ion pseudopotential is weak authors have developed a density functional theory for one-particle densities and thermodynamic properties of inhomogeneous liquid simple metals. They show Helmholtz free energy can be written as sum total electrostatic energy, non-Coulombic part an electron jellium Ge(n), corresponding quantity one-component classical plasma Gi( rho ) coupling term. In limit uniform their yields electron-electron, ion-ion direct correlation functions...

Linear screening theory for the interionic interaction in simple liquid metals is extended by including pair and three-ion interactions due to third-order perturbation term electron-ion interaction. Additional potentials, phi 2(3)(r), of both sodium potassium are large attractive short range. The position sharply rising part potential moves a smaller distance several percent with inclusion 2(3)(r). role 2(3)(r) essential if Anderson Weeks Chandler give good description structures. On other...

Effects of electron-ion interaction on the plasmon damping in metals are investigated by using a general formulation developed previous paper. Damping with small wavenumber q is mainly determined processes which dacays into (i) one electron-hole pair interband transition and (ii) simultaneous absorption or emission phonon. These give negative 2 -coefficient region. On other hand, process decays another phonon gives nearly proportional to . As whole, including contribution electron-electron...

The stability, electronic structure, and positron-electron pair momentum of body-centered-cubic (bcc) copper, which is metastable, are theoretically studied compared with those stable face-centered-cubic (fcc) copper ferromagnetic iron (bcc Fe). We first perform structure calculations based on the local-density approximation or generalized gradient (GGA) find that GGA well reproduces measured bulk properties, i.e., lattice constants, cohesive energies, moduli. calculated energies fcc bcc...

We have performed first-principles density-functional projector augmented-wave calculations to investigate the energetics of Mg and B adsorption on polar zinc oxide (ZnO) surfaces, thereby understand origin peculiar affinities between an epitaxial $\mathrm{Mg}{\mathrm{B}}_{2}$ film ZnO substrate. found that (0001) Zn surface is relatively inert, while $(000\overline{1})$ O very reactive in atomic species, where a triplaner $\mathrm{B}{\mathrm{O}}_{3}$ (a hump $\mathrm{Mg}{\mathrm{O}}_{3}$)...