New potential super-incompressible phase of ReN$_{2}$

The structural, elastic, and electronic properties of ReN$_{2}$ are investigated by first-principles calculations with density functional theory. The obtained orthorhombic $Pbcn$ structure is energetically the most stable structure at ambient pressure. ReN$_{2}$ is a metallic, superincompressible solid and presents a rather elastic anisotropy. The estimated Debye temperature and hardness are 735 K and 17.1 GPa, respectively. Its estimated hardness is comparative to that of Si$_{3}$N$_{4}$.