Face-centered-cubicB80metal: Density functional theory calculations

Abstract

Listen

Translate article

By means of ab initio calculations within the density functional theory, we have found that ${\text{B}}_{80}$ fullerenes can condense to form stable face-centered-cubic (fcc) solids. It is shown that when forming a crystal, ${\text{B}}_{80}$ cages are geometrically distorted, the ${\text{I}}_{h}$ symmetry is lowered to ${\text{T}}_{h}$, and four boron-boron chemical bonds are formed between every two nearest neighbor ${\text{B}}_{80}$ cages. The cohesive energy of ${\text{B}}_{80}$ fcc solid is 0.23 eV/atom with respect to the isolated ${\text{B}}_{80}$ fullerene. The calculated electronic structure reveals that the fcc ${\text{B}}_{80}$ solid is a metal. The predicted solid phase would constitute a form of pure boron and might have diverse implications. In addition, a simple electron counting rule is proposed, which could explain the stability of ${\text{B}}_{80}$ fullerene and the recently predicted stable boron sheet.