Structural, mechanical, and electronic properties of P21/m-Carbon✰

Abstract

The structural, mechanical, and electronic properties of P21/m-carbon were comprehensively investigated by using first principles calculations. Our calculated structure parameters are in good agreement with the previous theoretical values. P21/m-carbon consists of 10 atoms in a unit cell and is made of an exclusively sp3 hybridized bonding network. The calculated phonon spectra and elastic constant verify that P21/m-carbon is dynamically and mechanically stable at ambient pressure. The analysis of the electronic band structure reveals that P21/m-carbon is an insulator with a band gap of 5.47 eV. It has a large bulk moduli of 398 GPa and a high shear moduli of 457 GPa. Further mechanical properties demonstrate that P21/m-carbon is prone to be ductile and possesses a high Vickers hardness value of 82.3 GPa. These values show that P21/m-carbon simultaneously possesses ultra-incompressible and the superhard property. Furthermore, the X-ray diffraction spectra is also theoretically simulated to provide more structure information for future experimental observations.