Theoretical study of the hydrogen adsorption on AlB nanowire

Abstract

a b s t r a c tWe studied AlB nanowires as hydrogen storage materials based on density functional theory and Rigged QED theory. In this paper, we focused on the adsorption energy and the electronic structure of models. AlB nanowire models are compared with an Al nanowire model and AlB 2 crystal structure in terms of density of states, electron density, kinetic energy density, tension density and stress tensor density. These results revealed AlB nanowires do not have the conductivity, while the Al nanowire and AlB 2 bulk have it. It was also shown that the stabilization energies of AlB nanowires for the hydrogen adsorption are larger than that of Al nanowire. Adsorped hydrogens are more stable in the AlB nanowires than the Al nanowire.

The effect of electric current on chemical bonding of hydrogen adsorption on an aluminum nanowire

“…In comparison with Ref. , the shape of the surface with zero kinetic energy density is similar and the distribution pattern of the eigenvectors of stress tensor is also similar. However, the value of the largest eigenvalue of the stress tensor is larger than the work by about one order of magnitude.…”

“…This structure was optimized with keeping the fivefold symmetry in Ref. . The distance between the center of a pentagon and an aluminum nucleus on the pentagon is reduced to 2.35 Å.…”

“…In Refs. and , the aluminum nanowire, which has the structure tying Al 13 clusters one to the next, was studied as a candidate for hydrogen storage material. The chemical bonding between hydrogen and aluminum atoms was studied and classified as the covalent bond .…”

Theoretical study of lithium ionic conductors by electronic stress tensor density and electronic kinetic energy density

“…In order for efficient material search, it is important to characterize the chemical bonding of the lithium ionic conductors through the quantum chemical electronic structure calculation, and establish the connection with their material properties like chemical stability, diffusivity, and so on. We have been developing the characterization scheme of electronic structure using the electronic stress tensor density and kinetic energy density based on the rigged quantum electrodynamics (RQED) theory, and have applied it to various quantum systems . As a preliminary stage of our research, we have applied our method to the crystal structures of and .…”

“…Actually, as will be shown below, the stress tensor alone is not sufficient to characterize the ionicity and we need to see the pattern of the electronic kinetic energy density. Our definition of the kinetic energy density is not positive‐definite and there exist zero surfaces, which are designated as “electronic interfaces.” The outermost electronic interface can give a clear image of the intrinsic shape of atoms and molecules, and it has been used to investigate various chemical reactions in our past works . To characterize ionicity, the electronic interface is found to play an important role.…”