Potential ultra-incompressible material ReN: First-principles prediction

The structural, elastic and electronic properties of ReN are investigated by first-principles calculations based on density functional theory (DFT). The most stable structure of ReN is a NiAs-like structure, belonging to space group P63/mmcP63/mmc with a=2.7472a=2.7472 and c=5.8180c=5.8180 Å. ReN is a metallic ultra-incompressible solid and it exhibits low elastic anisotropy. Its linear incompressibility along the cc-axis exceeds that of diamond. Its ultra-incompressibility is attributed to the high valence electron density and strong covalence bondings. Our results indicate that ReN can be used as a potential ultra-incompressible conductor. In particular, a superconducting transition temperature is predicted as Tc≈4.8Tc≈4.8 K for NiAs-like ReN, which agrees well with the available experimental value.