Critical remark on the FSDP-related correlations in chalcogenide glasses as treated in the paper [Alekberov RI, Isayev AI, Mekhtiyeva SI, Fábián M. Local structures and optical properties of As-Se-Te(S) chalcogenide glasses. Phys B: Condens Matter 2018; 550: 367–375]

In the paper [Phys. B 550 (2018) 367–375], Alekberov, Isayev, Mekhtiyeva and Fábián have performed very erroneous calculation on diameter of voids responsible for the first sharp diffraction peak (FSDP) in neutron diffraction patterns of As2Se3-based glasses. The authors used wrong relation for the FSDP position taken from entirely speculative assertion presented by Kavetskyy in [Semicond. Phys. Quantum Electron. Optoelectron. 16 (2013) 136–139], assuming unreasonable equivalence between chemistry of chalcogenide glasses and typical polymers. In this communication, the deep reason for this incorrectness was disclosed, and alternative variant to estimate diameters of interstitial voids responsible for the FSDP in As2Se3-based glasses was presented. Keywords: Chalcogenide glass, Neutron diffraction, First sharp diffraction peak, Interstitial void, Positron annihilatio