′�?, having a frequency of 295 cm−1, is attributed on the stretching vibration of Ga–Se bonds. The two-phonon absorption with the 295 cm−1 phonon corresponds to your crystal IR absorption edge, instead of the residual absorption peak. Density functional theory computations exhibit which the residual absorption in the BGSe crystal https://baga4se7-crystal51516.liberty-blog.com/32747293/about-baga4se7-crystal