Ryoji Sahara

Lattice relaxation of monosize CeO2−x nanocrystalline particles

Lattice constants in monosize CeO2−x nanocrystalline particles increase with decreasing particle size. This phenomenon called lattice relaxation is well explained by the model that the number of surface oxygen is reduced to half and its nominal valence is not −2 or −0.5 but −1. This suggests that all the surface oxygen form O22− species in the nanocrystallites.

First-principles study of hydrogen storage over Ni and Rh doped BN sheets

Absorption of hydrogen molecules on Nickel and Rhodium-doped hexagonal boron nitride (BN) sheet is investigated by using the first principle method. The most stable site for the Ni atom was the on top side of nitrogen atom, while Rh atoms deservers a hollow site over the hexagonal BN sheet. The first hydrogen molecule was absorbed dissociatively over Rh atom, and molecularly on Ni doped BN sheet. Both Ni and Rh atoms are capable to absorb up to three hydrogen molecules chemically and the metal atom to BN sheet distance increases with the increase in the number of hydrogen molecules. Finally, our calculations offer explanation for the nature of bonding between the metal atom and the hydrogen molecules, which is due to the hybridization of metal d orbital with the hydrogen s orbital. These calculation results can be useful to understand the nature of interaction between the doped metal and the BN sheet, and their interaction with the hydrogen molecules.

Probing the Structure, Stability and Hydrogen Adsorption of Lithium Functionalized Isoreticular MOF-5 (Fe, Cu, Co, Ni and Zn) by Density Functional Theory

Li adsorption on isoreticular MOFs with metal Fe, Cu, Co, Ni and Zn was studied using density function theory. Li functionalization shows a considerable structural change associated with a volume change in isoreticular MOF-5 except for the Zn metal center. Hydrogen binding energies on Li functionalized MOFs are seen to be in the range of 0.2 eV, which is the desired value for an ideal reversible storage system. This study has clearly shown that Li doping is possible only in Zn-based MOF-5, which would be better candidate to reversibly store hydrogen.

First-principles study of the structural, electronic, and elastic properties of R Rh 3 B x C 1 − x ( R = Sc and Y)

We study the variation in the structural and electronic properties as well as bulk modulus of perovskite-type

Ab initio studies of structural, elastic, and electronic properties of RRh3BX (R=Sc, Y, La, and Ce)

R{\mathrm{Rh}}_{3}{\mathrm{B}}_{x}{\mathrm{C}}_{1\ensuremath{-}x}

Theoretical and experimental investigation of the excellent p–n control in yttrium aluminoborides

with

Body-centered-cubic lattice model with many-body interactions representing the melting transition in Si

R=\mathrm{Sc}

TOMBO: All-electron mixed-basis approach to condensed matter physics

and Y as a function of the boron concentration. These compounds are realized in the whole range of

A lattice Monte Carlo simulation of the FePt alloy using a first-principles renormalized four-body interaction.

0\ensuremath{\leqslant}x\ensuremath{\leqslant}1

Theoretical Investigation of Stabilizing Mechanism by Boron in Body-Centered Cubic Iron Through (Fe,Cr)23(C,B)6 Precipitates

in cubic structure. We use first-principles projected augmented wave method and the generalized gradient approximation for the exchange-correlation functional within the density-functional theory. Different configurations of boron and carbon atoms for a given