SrTcN 3 Nitride Perovskite: A First‐Principles Investigation of Electronic, Optical, Thermoelectric, Phonon, Thermodynamic, and Mechanical Properties

A comprehensive first‐principles study has been conducted on the nitride perovskite SrTcN 3 , focusing on its structural, electronic, thermal, optical, phonon, and mechanical properties. SrTcN 3 crystallises in a monoclinic phase with corner‐sharing TcN6 octahedra and demonstrates thermodynamic and dynamic stability. The Goldschmidt tolerance factor ∼0.98 and elastic constants confirm mechanical robustness. Electronic structure analysis reveals a semiconducting nature, featuring strong Tc 4d–N 2p hybridisation. High electrical conductivity and moderate Seebeck coefficients lead to a promising power factor. Optical properties include a high refractive index, strong absorption, and a static dielectric constant. Phonon dispersion analysis confirms the absence of imaginary modes, indicating dynamic stability, with a high Debye temperature. The combination of mechanical robustness, high Debye temperature, favourable electronic transport behaviour, strong optical absorption, and notable dielectric response positions SrTcN 3 as a theoretically promising multifunctional material, supporting further exploration for high‐temperature semiconducting environments, radiation‐tolerant platforms, and concept‐level dielectric or photonic applications.