Lattice Dynamics and Elastic Properties of GaSe

Abstract

Abstract Lattice dynamics of gallium selenide is studied by using both, the Born‐von Karman model with 22 interatomic force constants and the central two‐body‐force model with 10 constants ignoring completely any long‐range interaction. The second model including four equilibrium conditions leads to a good description of the elastic properties. The isolated layer dynamics is also considered. The striking feature of the acoustical modes appearing in an isolated layer is the quadratic dispersion of the out‐of‐plane acoustical mode in a small part of the Brillouin zone.