Showing papers by "Susumu Saito published in 2007"
TL;DR: In this paper, the reactivities of I h C 60 and D 5 h C 70 fullerenes were studied in the framework of density functional theory and the reaction energy was defined as energy gain at the minimum energy configuration from the infinite distance configuration.
Abstract: We study the reactivities of I h C 60 and D 5 h C 70 fullerenes in the framework of the density-functional theory To quantify the reactivities of fullerenes, we calculate the total energies of the system consisting of a fullerene and a C atom as a function of the distance from each C site on the fullerene surface to the C atom, and obtain the reaction energy defined as energy gain at the minimum-energy configuration from the infinite distance configuration Surprisingly, it is found that some of the C 70 sites have larger reaction energies than that of C 60 , although C 70 is energetically more stable than C 60 This result sheds new light on the formation process of fullerenes and the abundance of C 60 in soot
9 citations
TL;DR: In this article, the energy and electronic structure of MgB 2 nanotubes were studied in the framework of density-functional theory and it was found that in the case of (4,4) nanotube, the presence of the outer M...
Abstract: We study the energetics and the electronic structure of MgB 2 nanotubes in the framework of the density-functional theory. It is found that in the case of (4,4) nanotube the presence of the outer M...
6 citations
TL;DR: In this paper, it was shown that chemical bonding in deltahedral boron hydrides can be understood within the three-center two-electron (3c2e) bonding model in line with other families of boranes.
Abstract: We demonstrate, based on first-principles calculations, that chemical bonding in deltahedral boron hydrides, BnHn2- also known as closo boranes, can be understood within the three-center two-electron (3c2e) bonding model in line with other families of boranes. We show that bonding in the triangular lattice of BnHn2- cages can be described by delocalized resonant 3c2e bonding. We also find that the reason for all the BnHn2- to be dianions can be attributed to the reduction of boron coordination number in the deltahedral cage structure from that of boron sheet with triangular lattice.
1 citations
TL;DR: In this article, the temperature-dependent site selectivities of Cs and Rb ions in CsRb2C60 and Cs2RbC60 superconductors are computed using the free energy obtained from the configuration entropy and the total energy calculated using the ab initio pseudopotential density-functional theory.