Insights into the Prediction Structural, Electronic, Optic, Elastic, and Phonon Properties of Half-Heusler Compound LiAgSe via Density Functional Theory

Abstract

The structural, electronic, optic, elastic and dynamic features of LiAgSe half-Heusler structure are studied by using first principle calculations. LiAgSe half-Heusler compound is examined with the Generalized Gradient Approximation using the Density Functional Theory. The Quantum Espresso simulation program is preferred to investigate its structural, electronic and dynamic features. The ABINIT simulation program is preferred to investigate its elastic and optic properties. The electronic band structure graph of the LiAgSe crystal formed as a result of the calculation shows that this crystal has a semi-metallic structure. Optic properties such as, complex dielectric constant, extinction coefficient, reflectivity, for the volume of LiAgSe are calculated and plotted. In this study, elastic constants, Poisson's ratio and Debye Temperature values of LiAgSe half-Heusler crystal are determined. Apart from these, phonon dispersion curve graph is obtained. It has been calculated that the LiAgSe half-Heusler crystal is not dynamically stable in the ground state. However, when applied a pressure under nearly 16.396 GPa the crystal becomes stable.