Structural and Vibrational Properties of Strontium Chalcogenides

In the present work, various physical properties viz., equilibrium lattice constant, isothermal bulk modulus, its pressure derivative, total energy, equation of state, phonon dispersion, p-dos, electronic band structure, pressure induced phase transition have been calculated using plane wave pseudopotential density functional theory (DFT) as implemented in Quantum Espresso code (QE). The calculated cohesive properties of all compounds studied here are found to agree well with the corresponding theoretical and experimental data available in literature. In particular, the isothermal bulk modulus, which is a direct test of validity of any self consistent calculation of total energy of a material (which is calculated here by fitting the total energies to the Murnaghan equation of state for all four compounds), agrees well with the experimental data and in line with the other theoretical findings.