Structural stabilities, electronic and elastic properties for LaSb: A first-principles study

We theoretically study the pressure induced solid–solid phase transitions, electronic and elastic properties of LaSb by using first-principles calculations based on density functional theory (DFT), in the presence and in the absence of spin–orbit coupling (SOC). The calculations indicate that there exists a structural phase transition from NaCl-type (B1) structure to body centered tetragonal (BCT) structure at the transition pressure ( p t ) of 13.73 GPa (without SOC) and 13.84 GPa (with SOC). The origin of the SOC having a minor effect on obtaining p t was analyzed. The chemical bond between La and Sb is mainly ionic. The calculated band structures indicate that B1 and BCT phases of LaSb are metallic. A pseudogap appears around the Fermi level of the total density of states (DOS) of B1-LaSb, which may contribute to its stability. The calculated elastic constants are well consistent with the experimental values.