First-Principles Study of Structural, Electronic, and Elastic Properties of Sb₂S₃ under Pressure

The effects of pressure on the lattice parameters, electronic properties and elastic properties of Sb₂S₃ under 0–30 GPa are studied by first-principles calculation. The calculated results of structural parameters of generalized gradient approximation (GGA)-Perdew–Burke–Ernzerhof (PBE) are less than 3% different from the previous experimental values. With the increase of pressure, the bandgap of Sb₂S₃ becomes smaller and smaller. At a pressure of 35 GPa, the conduction band coincides with the valence band. Metallization will occur. The Poisson's ratio results show that the Poisson's ratio of Sb₂S₃ crystal is 0.2892 at 10 GPa. When the pressure increases to 30 GPa, the mechanical stability criterion is no longer satisfied, and the mechanical properties will be unstable. At atmospheric pressure, there is no virtual screen in the phonon dispersion spectrum of Sb₂S₃. At 30 GPa, the phonon appears virtual screen and the structure is unstable. This is consistent with the results of the previous mechanical stability calculation. Finally, the wave velocity and anisotropy of Sb₂S₃ are calculated by its elastic coefficients. All the conclusions, herein, can provide a theoretical basis for the future study of Sb₂S₃ under high pressure. So, it is necessary to study the skills of Sb₂S₃ under high pressure.