A computational estimation on structural, electronic, elastic, optic and dynamic properties of Li2TlA (A=Sb and Bi): First-principles calculations

The structural, electronic, optic, elastic and dynamic properties of Li2TlSb and Li2TlBi full-Heusler structure are studied by first principles calculations. The plane wave pseudo-potential method with a generalized gradient approximation was used to calculate all these properties. Quantum Espresso program was used to examine structural, electronic and dynamic properties, and Abinit program was used to examine optical and elastic properties. The change correlation function chosen is the Perdew - Burke - Ernzerhof function. The currently calculated structural properties are in good agreement with other theoretical results. Based on the linear harmony of the stress-strain relationship, the elastic constants of these structures have been determined. Poisson's coefficients and Zener anisotropy factor, Bulk, Shear and Young Module are computed. With the density functional perturbation theory, the frequencies of the phonon distribution spectra throughout the entire brillouin region were calculated and all values were found to be positive. These results show that the dynamic stabilities of Li2TlBi and Li2TlSb crystals are strong. The results obtained in this study are thought to be useful in future scientific studies to explore the applications of these materials such as optoelectronic devices and sensors.