High Pressure Phase Transition and Elastic Properties of Lutetium Monopnictides

The pressure induced structural phase transition and elastic properties of lutatium monopnictides LuX (⁠$X = N,$ P, Bi) have been studied using the first principles density functional theory within the generalized gradient approximation. The present work indicates that there is a structural phase transition from their ambient NaCl‐ $(B1)$ structure to CsCl‐ $(B2)$ structure at 299, 105 and 27 GPa along with the volume collapse of 4.7, 6.8 and 7.0%, respectively. Structural parameters like lattice constant $(a0),$ bulk modulus (B) and pressure derivatives of bulk moduli (B′) are presented. We also report the second order elastic constants for these compounds.