Soufyane Belhachi, Alsanaoyt Alhmidy, Munerah Aziz Alharbi, Mika Sillanpaa
A comprehensive first-principles investigation within the GGA[Formula: see text] framework was performed to explore the structural, electronic, magnetic, thermodynamic and optical properties of the inverse perovskite nitrides Er 3 AlN, Tm 3 AlN and Yb 3 AlN. To the best of our knowledge, this study represents the first systematic and comparative analysis of these late rare-earth anti-perovskite nitrides, addressing the lack of detailed understanding of their fundamental properties. The results confirmed that all compounds are thermodynamically stable in a cubic structure, with optimized lattice parameters in the range of 4.78–4.80[Formula: see text]Å. Electronic structure calculations revealed a metallic nature for all systems, accompanied by a ferromagnetic ground state, particularly pronounced in Tm 3 AlN, highlighting their potential for spin-dependent applications. The calculated bulk moduli (64.1–69.3[Formula: see text]GPa) indicated good mechanical stability. Optical analysis showed strong responses in the (4–8[Formula: see text]eV) energy range, associated with interband transitions and metallic reflectivity. Furthermore, complementary neutron-transport simulations demonstrated enhanced neutron absorption capabilities, with a performance trend of Er 3 AlN [Formula: see text] Tm 3 AlN [Formula: see text] Yb 3 AlN, supporting their relevance in radiation-tolerant environments. Overall, the combination of metallicity, magnetic ordering, thermal stability and optical activity establishes these materials as promising candidates for advanced functional applications, including spintronics, UV optoelectronics and radiation-resistant technologies.