Masayoshi Mikami

First-principles computation of material properties: the ABINIT software project

The density functional theory (DFT) computation of electronic structure, total energy and other properties of materials, is a field in constant progress. In order to stay at the forefront of knowledge, a DFT software project can benefit enormously from widespread collaboration, if handled properly. Also, modern software engineering concepts can considerably ease its development. The ABINIT project relies upon these ideas: freedom of sources, reliability, portability, and self-documentation are emphasised, in the development of a sophisticated plane-wave pseudopotential code. We describe ABINITv3.0, distributed under the GNU General Public License. The list of ABINITv3.0 capabilities is presented, as well as the different software techniques that have been used until now: PERL scripts and CPP directives treat a unique set of FORTRAN90 source files to generate sequential (or parallel) object code for many different platforms; more than 200 automated tests secure existing capabilities; strict coding rules are followed; the documentation is extensive, including online help files, tutorials, and HTML-formatted sources

A brief introduction to the ABINIT software package

Abstract A brief introduction to the ABINIT software package is given. Available under a free software license, it allows to compute directly a large set of properties useful for solid state studies, including structural and elastic properties, prediction of phase (meta)stability or instability, specific heat and free energy, spectroscopic and vibrational properties. These are described, and corresponding applications are presented. The emphasis is also laid on its ease of use and extensive documentation, allowing newcomers to quickly step in.

Host-to-activator energy transfer in a new blue-emitting phosphor SrHfO3 : Tm3+

Abstract A new phosphor, SrHfO3xa0:xa0Tm3+, shows a blue luminescence of high color purity with a peak at 457xa0nm originated from 3 P 0 state. Below the fundamental absorption edge at around 200xa0nm, an excitation band presumably due to a charge transfer state (CTS) of Tm3+ is observed. This situation allows efficient energy transfer from the host to Tm3+ via the CTS, providing a relatively high-energy efficiency of Tm3+ luminescence in oxides, which is about 4% under 25xa0kV electron-beam excitation.

First-principles study of yttrium oxysulfide: bulk and its defects

Abstract First-principles electronic-structure calculations of yttrium oxysulfide (Y 2 O 2 S) and its intrinsic point defects have been performed for the first time. From the calculation of the bulk, it is found that the material has an indirect band gap and that the top of the valence bands shows anisotropic character which means anisotropic mass of the hole. From the calculation of the defects, it is found that the anion vacancies and the interstitial sulfur induce relatively deep levels in the band gap, whereas the interstitial oxygen induces relatively a shallow hole trap level. These findings are discussed with defect-related phenomena in the oxysulfides. Further, negative-U characters are found in the oxygen vacancy and the interstitial sulfur from the result of the defect formation energies. These defect properties can be explained from the viewpoint of covalency of the bonds newly appearing in the defect geometries.

First-principles study ofCe3+-dopedlanthanum silicate nitride phosphors: Neutral excitation, Stokes shift, and luminescent center identification

We study from first principles two lanthanum silicate nitride compounds, LaSi

Lattice dynamics and optical properties of yttrium oxysulfide

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Nonlinear cathodoluminescence from insulators

N

First-principles study of the luminescence of Eu2+-doped phosphors

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Lattice dynamics and dielectric properties of TiO 2 anatase: A first-principles study

and La

COMPLEX OXYNITRIDE PHOSPHOR, LIGHT-EMITTING DEVICE USING SAME, IMAGE DISPLAY, ILLUMINATING DEVICE, PHOSPHOR-CONTAINING COMPOSITION AND COMPLEX OXYNITRIDE

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