MODEL OF A COVALENT PURE BORON QUASI-CRYSTAL

The possibility of constructing a model of covalent icosahedral phase of pure boron i-B, is shown by decorating a 3 D Penrose tiling from an idealized suitable icosahedral cluster extracted from the approximant rhombohedral crystal beta-B. Covalence means that the configuration of the first neighbouring atoms follows the rule of 5-fold inverted umbrellas. This covalent quasicrystal i-B, not yet discovered, would have the 6 dimensional space gronp F m ($) over bar 3 ($) over bar 5 and a quasilattice constant of 0.637 or 0.392 nm.