Phase transition, mechanical properties and stability of strontium chalcogenides under high pressure

Phase transition pressure, relative volume change and mechanical properties of strontium chalcogenides (SrX, X = S, Se, Te) have been studied. A potential model has been developed which includes Coulombic, three-body interaction, van der Waals forces, and overlap repulsive interaction operative up to second neighbor ions. This model is improved by including the covalency effects. It is found that the inclusion of covalency effect has improved the results.