First-principles study of the elastic and optical properties of the pseudocubic Si₃As₄, Ge₃As₄ and Sn₃As₄

The elastic and optical properties of Si₃As₄, Ge ₃As₄ and Sn₃As₄ systems with pseudocubic structure have been investigated by first-principles calculations. Our calculated results show that these compounds are mechanically stable after evaluating the calculated elastic constants. The calculated band structures and densities of state show that the three arsenides are semiconductors with narrow indirect band gaps. Furthermore, the optical constants, such as the dielectric function, refractive index and energy loss function, are calculated and presented in the study.