′�?, having a frequency of 295 cm−1, is attributed on the stretching vibration of Ga–Se bonds. The two-phonon absorption of the 295 cm−1 phonon corresponds towards the crystal IR absorption edge, as opposed to the residual absorption peak. Density functional idea computations clearly show the residual absorption in the BGSe https://baga4se7-crystal12221.p2blogs.com/31822199/a-simple-key-for-baga4se7-crystal-unveiled