CP-C20, a new metallic cubic carbon allotrope with an sp2 network

Abstract

A cubic carbon phase, called cP-C20, is predicted by first-principles calculations. CP-C20 belonging to Pm-3 symmetry consists of 20 atoms in a unit cell. It has an sp2 network and possesses hollow configurations. The calculated elastic constants and phonon properties confirm mechanical and dynamical stabilities in the new carbon phase. The ab initio molecular dynamics (MD) simulations confirm its thermal stability at 300 ​K and 1000K since the configuration can also keep after MD 20 ps. Moreover, there is a zero band gap in the band structure, revealing that this new metallic carbon allotrope may act as electrodes in electronic devices.