来源：Science Direct
Rare-earth mono-nitrides (REN) are important rare-earth compounds whose structural stability and electronic structure are strongly influenced by localized 4f states. In this work, a first-principles investigation is carried out on NdN, PmN, SmN, EuN, and GdN to examine their structural stability and electronic structure. Density Functional Theory (DFT) calculations using the Quantum Espresso package are employed to investigate the rocksalt (Fm–3m) and CsCl-type (Pm–3m) crystal phases. The calculated lattice parameters are compared with available experimental and theoretical values. Energy–volume relations are used to compare the relative energetic stability of the two phases, while band structures and density of states are examined to characterize the electronic states and orbital contributions. The results indicate that the rocksalt (Fm–3m) phase is energetically more favorable for the investigated compounds, whereas the Pm–3m phase has comparatively higher total energy. The electronic states near the Fermi level are strongly affected by localized rare-earth 4f states and their hybridization with N-2p and rare-earth 5d states. These results provide a theoretical description of the structural stability and electronic structure of the investigated rare-earth mononitrides.