′�?, using a frequency of 295 cm−1, is attributed to the stretching vibration of Ga–Se bonds. The 2-phonon absorption with the 295 cm−1 phonon corresponds to the crystal IR absorption edge, instead of the residual absorption peak. Density functional idea computations demonstrate that the residual absorption of your BGSe crystal https://baga4se7-crystal29629.theideasblog.com/33252567/not-known-details-about-baga4se7-crystal