Pressure induced Structural Phase Transition in SrS

Pressure induced structural phase transition in SrS from NaCl (B1) structure to CsCl (B2) structure has been studied using plane wave pseudopotential density functional theory as implemented in Quantum Espresso code. Ultrasoft pseudopotential along with generalised gradient approximation (GGA) has been used for total energy calculation. The electronic band structure has been calculated for B1 phase of SrS. We also report the vibrational properties such as phonon frequencies along major symmetry directions using density functional perturbation theory. The phase transition pressure is calculated by comparing enthalpies of both phases and its presently calculated value is 17.95 GPa, in very good agreement with the experimental results.