Diverse forms of $\sigma$ bonding in two-dimensional Si allotropes: Nematic orbitals in the $Mo{S}_2$ structure

Abstract

The interplay of $s{p}^2$- and $s{p}^3$-type bonding defines silicon allotropes in two- and three-dimensional forms. A novel two-dimensional phase bearing structural resembleance to a single MoS${}_2$ layer is found to possess a lower total energy than low-buckled silicene and to be stable in terms of its phonon dispersion relations. A new set of cigar-shaped, nematic orbitals originating from the Si $s{p}^2$ orbitals realizes bonding with a 6-fold coordination of the inner Si atoms of the layer. The identification of these nematic orbitals advocates diverse Si bonding configurations different from those of C atoms.

5 pages, 4 figures

References in corpus (4)

• Germanene: a novel two-dimensional Germanium allotrope akin to Graphene and Silicene
• Electronic structure of silicon-based nanostructures
• Local Reconstructions of Silicene Induced by Adatoms
• First-principles study on competing phases of silicene: Effect of substrate and strain

Cited by in corpus (3)

• Adsorption of Group-IV Elements on Graphene, Silicene, Germanene, Stanene: Dumbbell Formation
• Semimetallic single atomic layer silicon allotrope with Dirac fermions
• Atomically-thin metallic Si and Ge allotropes with high Fermi velocities