Determination and understanding of the structural electronic dynamic elastic and optic properties of Li2GaSb and Li3Sb by density functional theory

In this work, the structural, electronic, elastic, optical and dynamic properties of Li 3 Sb and Li 2 GaSb crystal structures were researched by using the density functional theory applied in Abinit and Quantum Espresso package programs. All calculations in both programs were performed using the Generalized Gradient Approximation as an exchange–correlation function in Kohn–Sham equations. When the structural properties of the crystals were examined, they were found to be in good agreement with other theoretical results. As a result of the calculations related to the electronic properties, it was determined that the Li 3 Sb crystal exhibited semiconducting properties and the Li 2 GaSb crystal exhibited metallic properties. Then, focusing on the dynamic properties of Li 3 Sb and Li 2 GaSb crystals, it was concluded that both crystals are dynamically stable. From the calculations made, it was concluded that the stable state did not deteriorate when pressure was applied to the Li 3 Sb crystal, but the stable state deteriorated when pressure was applied to the Li 2 GaSb crystal from 528 kbar pressure. In addition, the calculations showed that the thermal conductivity of Li 3 Sb is higher than that of Li 2 GaSb. By calculating the elastic properties, it was found that Li 3 Sb is a brittle material while Li 2 GaSb is an elastic material. Finally, based on the semiconductor properties of the Li 3 Sb crystal, its optical properties were investigated.