′�?, that has a frequency of 295 cm−1, is attributed for the stretching vibration of Ga–Se bonds. The two-phonon absorption of your 295 cm−1 phonon corresponds towards the crystal IR absorption edge, rather than the residual absorption peak. Density purposeful concept computations show the residual absorption with the BGSe crystal https://baga4se7crystal39517.thechapblog.com/32020136/the-smart-trick-of-baga4se7-crystal-that-nobody-is-discussing