Unveiling the Potential of Ba₂Zn₅As₆ and Ba₂Zn₅Sb₆: A Comprehensive DFT Study

Abstract In this study, the structural, elastic, electronic, optical, and thermoelectric properties of Ba 2 Zn 5 X 6 (X = As, Sb) compounds within the orthorhombic space group Pmna (No. 53) are investigated using density functional theory (DFT). The analysis of phonon dispersion and elastic constants confirms that the compounds are both dynamically and mechanically stable. These results indicate that the Ba 2 Zn 5 X 6 (X = As, Sb) compounds have relatively low mechanical properties, indicating that they are likely to have low thermal conductivity. The vibrations of Ba atoms play an important role in the phonon thermal conductivity. In terms of electronic properties, the band structure analysis indicates that the compounds possess an indirect band gap (Γ‐Y). The calculation of optical properties in the energy range 0–12 eV reveals important information about dielectric functions, refractive index, reflection, optical conductivity, and absorption coefficient. These calculations have shown that the compounds exhibit good optical efficiency. Furthermore, a detailed investigation and discussion of their thermoelectric properties, such as Seebeck coefficient, electronic thermal conductivity, and power factor, indicate that these compounds can be candidates for thermoelectric devices. These calculations provide valuable insights into enhancing the thermoelectric performance of these compounds.