Among the perspective research directions in modern physics, an important role is played by the investigation of amorphous nanostructures [1-3]. The effect of the drop in lattice thermal conductivity in these compounds can be used in thermoelectric applications [4, 5]. It is difficult both theoretically and practically to make in fact a distinction between truly amorphous solids and crystalline solids if the crystal sizes are very small [6]. Even amorphous materials have a certain short-range order at the atomic length scale due to the nature of chemical bonding. Furthermore, in very small crystals, a large fraction of the atoms are located at the crystal surface or near it; relaxation of the surface and interfacial effects distort the atomic positions and decrease the structural order.