New quasi-planar surfaces of bare boron

New very stable quasi-planar clusters of bare boron are found by systematic ab initio density functional and quantum chemical methods. They are composed of dove-tailed hexagonal pyramids different from the classical forms of alpha- or beta-rhombohedral boron crystallines. The quasi-planar structures are considered to be fragments of quasi-planar surfaces, which can easily be obtained and constructed from a basic unit of hexagonal pyramids. A new investigation on double layers of boron quasi-planar surfaces shows an increase in the stability of the system which can be related to the overlap of pi-orbitals between the layers. Therefore, we predict the existence of a series of parallel boron layers, as in graphite. These proposed surfaces can serve as lightweight protective armor, as a neutron-absorber material in fission reactions, or as very high temperature semiconductors.