First‐Principles Insights Into Structural Stability and Electronic Properties of La‐Substituted SrNbO ₃ (Sr _{0 .}

Using spin‐polarized density functional theory within the full‐potential linearized augmented plane wave framework, we investigated the structural and electronic properties of La‐substituted SrNbO ₃ (Sr _{0 . 875} La _{0 . 125} NbO ₃ ). We used volume optimization and equation‐of‐state fitting to check further structural stability. This showed that cubic symmetry was preserved after La atom was added by replacing Sr atom. The computed spin‐resolved electronic band structure shows that multiple bands cross the Fermi level, showing metallic behavior of material under doped condition. There is a distinct spin asymmetry observed at the Fermi energy. This is because 12.5% La doping at the Sr site causes finite spin polarization. The total density of states study shows that most of the electronic states at the Fermi level have contribution from Nb‐4d orbitals while the valence‐band region has substantial Nb 4d–O 2p hybridization. The contribution of Sr and La states near the Fermi level is relatively small, indicating that their primary role is to act as electron donors to the system. These results provide insight into the modification of electronic structure and spin characteristics of SrNbO ₃ upon La substitution and may serve as a basis for further theoretical and experimental investigations of doped perovskite oxides.