Silicon-based counterpart of alpha-graphyne

We present the first principles density functional calculations of electronic structure and energetics of silicon-based counterpart of alpha-graphyne, labeled as alpha-silicyne. Both LDA and GGA functionals are applied for exchange-correlation potentials. We show that graphyne-like silicon in 2D buckled structure (equilibrium buckling delta z congruent to 0.73 and Delta z congruent to 1.45 A) has approximate to 2.33 eV and approximate to 1.96 eV lower energies than planar geometry for GGA and LDA functionals, respectively. The single and triple bond lengths of silicon are consistent with previously reported values. As a different case from graphyne, which is semimetallic, the electronic band structures of buckled a-silicyne do not show Dirac fermion indicating a metallic nature. The metallic character of the system is largely determined by p-electronic states of the triple bonded silicon atoms. (C) 2014 Elsevier B.V. All rights reserved.