Ilchuk, H., M. Solovyov, I. Lopatynskyi, F. Honchar, and F. Tsyupko. 2021. “First Principles DFT Calculations of the Optical Properties of A4BX6 Group Crystals”. Physics and Chemistry of Solid State 22 (1):117-22. https://doi.org/10.15330/pcss.22.1.117-122.