  This paper presents ab inition calculations of the surface phonon spectra of
GeSe layered semiconductor compound, based on the Density Functional
Perturbation Theory (DFPT). The surface has been imitated by a structure of
periodically arranged slabs of two layers of GeSe crystal separated from other
identical layers by the layers of vacuum sufficiently wide to ignore the effect
of the upper boundary of the double-layer upon its lower boundary. We discuss
the character of the surface modes located in the gaps, in the pockets, and in
the area of allowed phonon states for the bulk GeSe crystals, as well as
outside (above and below) the boundaries of the bulk phonon states.
