title: Low-dimensional boron structures based on icosahedron B₁₂.
abstract: One-dimensional icosahedral boron chains and two-dimensional icosahedral boron sheets (icosahedral α, δ6, and δ4 sheets) that contain icosahedra B12 as their building units have been predicted in a computer simulation study using a state-of-the-art semi-empirical Hamiltonian. These novel low-dimensional icosahedral structures exhibit interesting bonding and electronic properties. Specifically, the three-center, two-electron bonding between icosahedra B12 of the boron bulk (rhombohedral boron) transforms into a two-center bonding in these new allotropes of boron sheets. In contrast to the previously reported stable buckled α and triangular boron monolayer sheets, these new allotropes of boron sheets form a planar network. Calculations of electronic density of states (DOS) reveal a semiconducting nature for both the icosahedral chain and the icosahedral δ6 and δ4 sheets, as well as a nearly gapless (or metallic-like) feature in the DOS for the icosahedral α sheet. The results for the energy barrier per atom between the icosahedral δ6 and α sheets (0.17 eV), the icosahedral δ6 and δ4 sheets (0.38 eV), and the icosahedral α and δ4 sheets (0.27 eV), as indicated in the respective parentheses, suggest that these new allotropes of boron sheets are relatively stable.
authors.affiliation: Department of Physics and Astronomy, University of Louisville, Louisville, Kentucky, 40292, USA.
authors.forename: C B
authors.initials: CB
authors.lastname: Kah
authors.forename: M
authors.initials: M
authors.lastname: Yu
authors.forename: P
authors.initials: P
authors.lastname: Tandy
authors.forename: C S
authors.initials: CS
authors.lastname: Jayanthi
authors.forename: S Y
authors.initials: SY
authors.lastname: Wu