Mechanical properties and electronic structure of the incompressible rhenium carbides and nitrides: A first-principles study

TL;DR

This study uses first-principles calculations to analyze the stability, mechanical properties, and electronic structure of newly synthesized incompressible rhenium carbides and nitrides, revealing their strong covalent bonding origins.

Contribution

It provides the first detailed computational investigation of Re2C, Re2N, Re3N, and Re3C, demonstrating their stability and incompressibility linked to covalent bonding and hybridization.

Findings

Re3C is stable and incompressible.

Incompressibility is due to strong covalent Re-C and Re-N bonds.

Electronic structure shows hybridization of Re 5d and C/N 2p orbitals.

Abstract

By means of first-principles calculations, the structural stability, mechanical properties and electronic structure of the newly synthesized incompressible Re2C, Re2N, Re3N and an analogous compound Re3C have been investigated. Our results agree well with the available experimental and theoretical data. The proposed Re3C is shown to be energetically, mechanically and dynamically stable and also incompressible. Furthermore, it is suggested that the incompressibility of these compounds is originated from the strong covalent bonding character with the hybridization of 5d orbital of Re and the 2p orbital of C or N, and a zigzag topology of interconnected bonds, e.g., Re-Re, Re-C or Re-N bonding.