P213 BN: a novel large-cell boron nitride polymorph

Abstract

A new boron nitride polymorph, P213 BN (space group: P213), is investigated by first-principles calculations, including its structural properties, stability, elastic properties, anisotropy and electronic properties. It is found that the new boron nitride polymorph P213 BN is mechanically, dynamically and thermodynamically stable. The bulk modulus (B), shear modulus (G) and Young’s modulus of P213 BN are 91 GPa, 41 GPa and 107 GPa, respectively, all of which are larger than that of Y carbon and TY carbon. By comparing with c-BN, the Young’s modulus, shear modulus and Poisson’s ratio of P213 BN show tiny anisotropy in the (001), (010), (100) and (111) planes. At the same time, in contrast with most boron nitride polymorphs, P213 BN is a semiconductor material with a smaller band gap of 1.826 eV. The Debye temperature and the anisotropic sound velocities of P213 BN are also investigated in this work.