arXiv subjects

S. Takami

Publications and source records attributed to S. Takami.

3 recordsLinked to original sources

arXiv1999

Density-functional-theory calculations of molecular nitrogen on ruthenium cluster

Density-functional-theory calculations for the adsorption of molecular nitrogen on ruthenium surface are reported. It is found that nitrogen molecule is adsorbed while standing perpendicular to the triangular surface of ruthenium. The doping by K atoms favours the adsorption of molecular nitrogen. The calculation of the adsorption energy has also been performed on iron and osmium clusters which shows that ruthenium adsorbs better than iron or osmium. It is found that potential for atomic nitrogen is deeper and more stable than that of molecular nitrogen and hence atomic nitrogen is important for catalysis.

cond-mat.mtrl-sci↗

arXiv1998

Non-axial Octupole Deformations of N=Z Nuclei in $A \sim 60-80$ Mass Region

By performing a fully three dimensional Hartree-Fock calculation with use of the Skyrm forces, we demonstrate possibility of exotic deformations violating both the reflection and the axial symmetries of N=Z nuclei in $A \sim 60-80$ mass region. The \Ytwo tetrahedral shape predicted in excited \Zr arises from a shell gap at $N,Z = 40$ which is enhanced for the tetrahedron deformation. Softness toward the \Ythree triangular deformation of the oblate state in \Se is also predicted.

nucl-th↗

arXiv1997

Tetrahedral and Triangular Deformations of $Z=N$ Nuclei in Mass Region $A \sim 60-80$

We study static non-axial octupole deformations in proton-rich $Z=N$ nuclei, $^{64}$Ge, $^{68}$Se, $^{72}$Kr, $^{76}$Sr, $^{80}$Zr and $^{84}$Mo, by using the Skyrme Hartree-Fock plus BCS calculation with no restrictions on the nuclear shape. The calculation predicts that the oblate ground state in $^{68}$Se is extremely soft for the $Y_{33}$ triangular deformation, and that in $^{80}$Zr the low-lying local minimum state coexisting with the prolate ground state has the $Y_{32}$ tetrahedral deformation.

nucl-th↗