′�?, having a frequency of 295 cm−1, is attributed on the stretching vibration of Ga–Se bonds. The two-phonon absorption on the 295 cm−1 phonon corresponds to your crystal IR absorption edge, rather then the residual absorption peak. Density practical theory computations clearly show the residual absorption of the BGSe crystal https://baga4se7crystal42841.blogerus.com/55125159/baga4se7-crystal-an-overview