Electronic and elastic properties of PbS under pressure

The electronic structures and elastic properties of lead sulfide are studied usingfirst-principles calculations. The energy band structure and density of state (DOS) of PbS at 0 GPa are calculated. The band gap energy of PbS versus the pressure 0–40 GPa is obtained. We find that the band gap energy decreases as the pressure increases. The geometry optimized structural parameters for PbS under different pressures are listed. The lattice parameter a, and enthalpy E both decrease with increasing pressure. However, parameter B, S and Y increase with pressure. The normalized lattice constants and the elastic modulus as two functions of pressure from 0–40 GPa are obtained. The calculated elastic constants C11 and C12 increase but with different rates under increasing pressure. However, C44 decrease under increasing pressure.