′�?, by using a frequency of 295 cm−one, is attributed to your stretching vibration of Ga–Se bonds. The 2-phonon absorption on the 295 cm−1 phonon corresponds towards the crystal IR absorption edge, as opposed to the residual absorption peak. Density functional theory computations display the residual absorption from the BGSe https://arthurhnool.digitollblog.com/32443484/baga4se7-crystal-an-overview