First-principles approach was used to explore the structural, mechanical, electronic and optical properties of the chalcogenide compound La \(_{2}\) ZrSe \(_{5}\) in its orthorhombic phase. To the best of one’s knowledge, a number of this compound’s physical characteristics, including its electronic properties, mechanical behavior, optical dispersion behavior and vibrational characteristics are still understudied. The calculated lattice parameters and unit cell volume are compared with those from previous research to check the reliability of our findings. By analyzing its elastic constants, the mechanical stability of La \(_{2}\) ZrSe \(_{5}\) is evaluated, showing its mechanical resilience. The material’s analysis of mechanical descriptors, including the independent elastic coefficients of bulk, shear and Young’s modulus, as well as ratios such as Pugh’s and Poisson’s ratio, suggests anisotropic and ductile behavior. The electronic properties were further examined by figuring out the band structure, partial and total density of states. According to the findings, La \(_{2}\) ZrSe \(_{5}\) is a semiconductor with a fundamental band gap of approximately 1.25 eV as computed using hybrid functional, suggesting that it may find use in optoelectronics such as photodetectors, field effect transistors, light-emitting diodes and electronics. This work will provide helpful guidance for future experiments and theoretical investigations of the material.
