Microscopic partition of pressure and elastic constants in CdTe polymorphs

• Pressure ranges of stability of CdTe polymorphs are successfully computed.
• A cubic B2 phase is predicted at pressures above 70 GPa.
• Microscopic pressures are defined without resorting to energy partitions.
• Cd shows a greater mechanical resistance than Te when pressure is applied.
• Atomic equations of state are proposed for Cd and Te along the polymorphic sequence.

Within the framework of density functional theory, first principles calculations were carried out to determine pressure stability ranges of zinc-blende (B3), cinnabar (Cinn), rock-salt (B1), orthorhombic (Cmcm  ), and cesium chloride (B2) phases of CdTe. In agreement with experimental observations, we found a B3→Cinn→B1→Cmcm pressure-induced sequence, and predict the B2 phase as a potential high pressure polymorph. The equations of state of all these polymorphs and the components of the elasticity tensor of the B3 phase at zero pressure were determined and microscopically analyzed in terms of atomic contributions. The concept of local pressure allows for quantifying differences in the role played by Cd and Te as regards the compressibility of CdTe phases, and suggests the existence of a general behavior under pressure for binary II–VI semiconductors.