First-principles investigation of structural, electronic, and optical, features of NaXO ₃ (X = Cr, Mo) single perovskite materials for energy storage, catalysis, and optoelectronic applications

In this study we have explored the structure, elastic, optoelectronic, and thermodynamic properties of cubic NaXO ₃ (X = Cr, Mo) perovskites, using first-principles calculations with the density functional theory within Wien2k frame work. Structural optimization is used in the cubic phase to confirm the lattice stability and its mechanical stability is checked by calculating the elastic constants. Phonon dispersion and quasi-harmonic thermodynamic studies establish the existence of localized soft modes in cubic NaCrO ₃ , whereas NaMoO ₃ is dynamically stable; both compounds have strong vibrational properties and show no signs of thermal phase transitions in the temperature range studied. Elastic constants demonstrate mechanical stability and brittle nature for NaCrO ₃ while ductile behavior for NaMoO ₃ , which is backed up by Cauchy pressures and Pugh ratio analysis. Both compounds are suggestively metallic in nature according to electronic band structure and density of states calculations, and highly spin polarized. NaCrO ₃ has strong magnetism and NaMoO ₃ has weak magnetism. Optical analysis shows high reflectivity in the low-energy regime and dielectric response of a metallic type. The results offer theoretical understanding of the multifunctional nature of the NaXO ₃ (X = Cr, Mo) perovskites and their use in spintronic and energy storage applications.